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89
Long-Term Climate and Development Futures
Section 3
3.4.2 Advancing Integrated Climate Action for Sustainable
Development
An inclusive, equitable approach to integrating adaptation, mitigation
and development can advance sustainable development in the long
term (high confidence). Integrated responses can harness synergies for
sustainable development and reduce trade-offs (high confidence). Shifting
development pathways towards sustainability and advancing climate
resilient development is enabled when governments, civil society
and the private sector make development choices that prioritise risk
reduction, equity and justice, and when decision-making processes,
finance and actions are integrated across governance levels, sectors
and timeframes (very high confidence) (see also Figure 4.2). Inclusive
processes involving local knowledge and Indigenous Knowledge
increase these prospects (high confidence). However, opportunities
for action differ substantially among and within regions, driven by
historical and ongoing patterns of development (very high confidence).
Accelerated financial support for developing countries is critical to enhance
mitigation and adaptation action (high confidence). {WGII SPM C.5.4,
WGII SPM D.1, WGII SPM D.1.1, WGII SPM D.1.2, WGII SPM D.2,
WGII SPM D.3, WGII SPM D.5, WGII SPM D.5.1, WGII SPM D.5.2;
WGIII SPM D.1, WGIII SPM D.2, WGIII SPM D.2.4, WGIII SPM E.2.2,
WGIII SPM E.2.3, WGIII SPM E.5.3, WGIII Cross-Chapter Box 5}
Policies that shift development pathways towards sustainability
can broaden the portfolio of available mitigation and adaptation
responses (medium confidence). |
{WGII SPM C.5.4,
WGII SPM D.1, WGII SPM D.1.1, WGII SPM D.1.2, WGII SPM D.2,
WGII SPM D.3, WGII SPM D.5, WGII SPM D.5.1, WGII SPM D.5.2;
WGIII SPM D.1, WGIII SPM D.2, WGIII SPM D.2.4, WGIII SPM E.2.2,
WGIII SPM E.2.3, WGIII SPM E.5.3, WGIII Cross-Chapter Box 5}
Policies that shift development pathways towards sustainability
can broaden the portfolio of available mitigation and adaptation
responses (medium confidence). Combining mitigation with action
to shift development pathways, such as broader sectoral policies,
approaches that induce lifestyle or behaviour changes, financial
regulation, or macroeconomic policies can overcome barriers and
open up a broader range of mitigation options (high confidence).
Integrated, inclusive planning and investment in everyday decision-
making about urban infrastructure can significantly increase the
adaptive capacity of urban and rural settlements. Coastal cities and
settlements play an important role in advancing climate resilient
development due to the high number of people living in the Low
Elevation Coastal Zone, the escalating and climate compounded risk
that they face, and their vital role in national economies and beyond
(high confidence). {WGII SPM.D.3, WGII SPM D.3.3; WGIII SPM E.2,
WGIII SPM E.2.2; SR1.5 SPM D.6}
Observed adverse impacts and related losses and damages,
projected risks, trends in vulnerability, and adaptation limits
demonstrate that transformation for sustainability and climate
resilient development action is more urgent than previously
assessed (very high confidence). Climate resilient development
integrates adaptation and GHG mitigation to advance
sustainable development for all. |
Coastal cities and
settlements play an important role in advancing climate resilient
development due to the high number of people living in the Low
Elevation Coastal Zone, the escalating and climate compounded risk
that they face, and their vital role in national economies and beyond
(high confidence). {WGII SPM.D.3, WGII SPM D.3.3; WGIII SPM E.2,
WGIII SPM E.2.2; SR1.5 SPM D.6}
Observed adverse impacts and related losses and damages,
projected risks, trends in vulnerability, and adaptation limits
demonstrate that transformation for sustainability and climate
resilient development action is more urgent than previously
assessed (very high confidence). Climate resilient development
integrates adaptation and GHG mitigation to advance
sustainable development for all. Climate resilient development
pathways have been constrained by past development, emissions and
climate change and are progressively constrained by every increment
of warming, in particular beyond 1.5°C (very high confidence).
Climate resilient development will not be possible in some regions
and sub-regions if global warming exceeds 2°C (medium confidence).
Safeguarding biodiversity and ecosystems is fundamental to climate
resilient development, but biodiversity and ecosystem services have
limited capacity to adapt to increasing global warming levels, making
climate resilient development progressively harder to achieve beyond
1.5°C warming (very high confidence). {WGII SPM D.1, WGII SPM D.1.1,
WGII SPM D.4, WGII SPM D.4.3, WGII SPM D.5.1; WGIII SPM D.1.1}
The cumulative scientific evidence is unequivocal: climate change
is a threat to human well-being and planetary health (very
high confidence). Any further delay in concerted anticipatory
global action on adaptation and mitigation will miss a brief and
rapidly closing window of opportunity to secure a liveable and
sustainable future for all (very high confidence). Opportunities for
near-term action are assessed in the following section. |
{WGII SPM D.1, WGII SPM D.1.1,
WGII SPM D.4, WGII SPM D.4.3, WGII SPM D.5.1; WGIII SPM D.1.1}
The cumulative scientific evidence is unequivocal: climate change
is a threat to human well-being and planetary health (very
high confidence). Any further delay in concerted anticipatory
global action on adaptation and mitigation will miss a brief and
rapidly closing window of opportunity to secure a liveable and
sustainable future for all (very high confidence). Opportunities for
near-term action are assessed in the following section. {WGII SPM D.5.3;
WGIII SPM D.1.1} |
90 |
91
Section 4
Near-Term Responses
in a Changing Climate |
92
Section 4
Section 1
Section 4
Section 4 : Near-Term Responses in a Changing Climate
4.1 The Timing and Urgency of Climate Action
The magnitude and rate of climate change and associated risks
depend strongly on near-term mitigation and adaptation actions
(very high confidence). Global warming is more likely than not to reach
1.5°C between 2021 and 2040 even under the very low GHG emission
scenarios (SSP1-1.9), and likely or very likely to exceed 1.5°C under
higher emissions scenarios141. Many adaptation options have medium
or high feasibility up to 1.5°C (medium to high confidence, depending
on option), but hard limits to adaptation have already been reached
in some ecosystems and the effectiveness of adaptation to reduce
climate risk will decrease with increasing warming (high confidence).
Societal choices and actions implemented in this decade determine the
extent to which medium- and long-term pathways will deliver higher or
lower climate resilient development (high confidence). Climate resilient
development prospects are increasingly limited if current greenhouse
gas emissions do not rapidly decline, especially if 1.5°C global warming
is exceeded in the near term (high confidence). Without urgent, effective
and equitable adaptation and mitigation actions, climate change
increasingly threatens the health and livelihoods of people around
the globe, ecosystem health, and biodiversity, with severe adverse
consequences for current and future generations (high confidence).
{WGI SPM B.1.3, WGI SPM B.5.1, WGI SPM B.5.2; WGII SPM A, WGII
SPM B.4, WGII SPM C.2, WGII SPM C.3.3, WGII Figure SPM.4, WGII SPM
D.1, WGII SPM D.5, WGIII SPM D.1.1 SR1.5 SPM D.2.2}. |
Without urgent, effective
and equitable adaptation and mitigation actions, climate change
increasingly threatens the health and livelihoods of people around
the globe, ecosystem health, and biodiversity, with severe adverse
consequences for current and future generations (high confidence).
{WGI SPM B.1.3, WGI SPM B.5.1, WGI SPM B.5.2; WGII SPM A, WGII
SPM B.4, WGII SPM C.2, WGII SPM C.3.3, WGII Figure SPM.4, WGII SPM
D.1, WGII SPM D.5, WGIII SPM D.1.1 SR1.5 SPM D.2.2}. (Cross-Section
Box.2, Figure 2.1, Figure 2.3)
141 In the near term (2021–2040), the 1.5°C global warming level is very likely to be exceeded under the very high GHG emissions scenario (SSP5-8.5), likely to be exceeded under
the intermediate and high GHG emissions scenarios (SSP2-4.5, SSP3-7.0), more likely than not to be exceeded under the low GHG emissions scenario (SSP1-2.6) and more likely
than not to be reached under the very low GHG emissions scenario (SSP1-1.9). The best estimates [and very likely ranges] of global warming for the different scenarios in the
near term are: 1.5 [1.2 to 1.7]°C (SSP1-1.9); 1.5 [1.2 to 1.8]°C (SSP1-2.6); 1.5 [1.2 to 1.8]°C (SSP2-4.5); 1.5 [1.2 to 1.8]°C (SSP3-7.0); and 1.6[1.3 to 1.9]°C (SSP5-8.5). |
The best estimates [and very likely ranges] of global warming for the different scenarios in the
near term are: 1.5 [1.2 to 1.7]°C (SSP1-1.9); 1.5 [1.2 to 1.8]°C (SSP1-2.6); 1.5 [1.2 to 1.8]°C (SSP2-4.5); 1.5 [1.2 to 1.8]°C (SSP3-7.0); and 1.6[1.3 to 1.9]°C (SSP5-8.5).
{WGI SPM B.1.3, WGI Table SPM.1} (Cross-Section Box.2)
142 Values in parentheses indicate the likelihood of limiting warming to the level specified (see Cross-Section Box.2).
143 Median and very likely range [5th to 95th percentile]. {WGIII SPM footnote 30}
144 These numbers for CO2 are 48 [36 to 69]% in 2030, 65 [50 to 96] % in 2035, 80 [61 to109] % in 2040 and 99 [79 to 119]% in 2050.
145 These numbers for CO2 are 22 [1 to 44]% in 2030, 37 [21 to 59] % in 2035, 51 [36 to 70] % in 2040 and 73 [55 to 90]% in 2050.
146 In this context, ‘unabated fossil fuels’ refers to fossil fuels produced and used without interventions that substantially reduce the amount of GHG emitted throughout the life
cycle; for example, capturing 90% or more CO2 from power plants, or 50 to 80% of fugitive methane emissions from energy supply. |
{WGIII SPM footnote 30}
144 These numbers for CO2 are 48 [36 to 69]% in 2030, 65 [50 to 96] % in 2035, 80 [61 to109] % in 2040 and 99 [79 to 119]% in 2050.
145 These numbers for CO2 are 22 [1 to 44]% in 2030, 37 [21 to 59] % in 2035, 51 [36 to 70] % in 2040 and 73 [55 to 90]% in 2050.
146 In this context, ‘unabated fossil fuels’ refers to fossil fuels produced and used without interventions that substantially reduce the amount of GHG emitted throughout the life
cycle; for example, capturing 90% or more CO2 from power plants, or 50 to 80% of fugitive methane emissions from energy supply. {WGIII SPM footnote 54}
In modelled pathways that limit warming to 1.5°C (>50%) with
no or limited overshoot and in those that limit warming to
2°C (>67%), assuming immediate actions, global GHG emissions
are projected to peak in the early 2020s followed by rapid and
deep GHG emissions reductions (high confidence) 142. In pathways
that limit warming to 1.5°C (>50%) with no or limited overshoot, net
global GHG emissions are projected to fall by 43 [34 to 60]%143 below
2019 levels by 2030, 60 [49 to 77]% by 2035, 69 [58 to 90]% by 2040
and 84 [73 to 98]% by 2050 (high confidence) (Section 2.3.1, Table 2.2,
Figure 2.5, Table 3.1)144. |
In pathways
that limit warming to 1.5°C (>50%) with no or limited overshoot, net
global GHG emissions are projected to fall by 43 [34 to 60]%143 below
2019 levels by 2030, 60 [49 to 77]% by 2035, 69 [58 to 90]% by 2040
and 84 [73 to 98]% by 2050 (high confidence) (Section 2.3.1, Table 2.2,
Figure 2.5, Table 3.1)144. Global modelled pathways that limit warming
to 2°C (>67%) have reductions in GHG emissions below 2019 levels
of 21 [1 to 42]% by 2030, 35 [22 to 55] % by 2035, 46 [34 to 63]
% by 2040 and 64 [53 to 77]% by 2050145 (high confidence). Global
GHG emissions associated with NDCs announced prior to COP26 would
make it likely that warming would exceed 1.5°C (high confidence)
and limiting warming to 2°C (>67%) would then imply a rapid
acceleration of emission reductions during 2030–2050, around
70% faster than in pathways where immediate action is taken to
limit warming to 2°C (>67%) (medium confidence) (Section 2.3.1)
Continued investments in unabated high-emitting infrastructure146 and
limited development and deployment of low-emitting alternatives
prior to 2030 would act as barriers to this acceleration and increase
feasibility risks (high confidence). {WGIII SPM B.6.3, WGIII 3.5.2,
WGIII SPM B.6, WGIII SPM B.6., WGIII SPM C.1, WGIII SPM C1.1,
WGIII Table SPM.2} (Cross-Section Box.2)
Deep, rapid, and sustained mitigation and accelerated implementation of adaptation reduces the risks of climate
change for humans and ecosystems. |
{WGIII SPM B.6.3, WGIII 3.5.2,
WGIII SPM B.6, WGIII SPM B.6., WGIII SPM C.1, WGIII SPM C1.1,
WGIII Table SPM.2} (Cross-Section Box.2)
Deep, rapid, and sustained mitigation and accelerated implementation of adaptation reduces the risks of climate
change for humans and ecosystems. In modelled pathways that limit warming to 1.5°C (>50%) with no or limited
overshoot and in those that limit warming to 2°C (>67%) and assume immediate action, global GHG emissions
are projected to peak in the early 2020s followed by rapid and deep reductions. As adaptation options often have
long implementation times, accelerated implementation of adaptation, particularly in this decade, is important
to close adaptation gaps. (high confidence) |
93
Near-Term Responses in a Changing Climate
Section 4
All global modelled pathways that limit warming to 2°C (>67%)
or lower by 2100 involve reductions in both net CO2 emissions
and non-CO2 emissions (see Figure 3.6) (high confidence).
For example, in pathways that limit warming to 1.5°C (>50%)
with no or limited overshoot, global CH4 (methane) emissions are
reduced by 34 [21 to 57]% below 2019 levels by 2030 and by
44 [31 to 63]% in 2040 (high confidence). Global CH4 emissions
are reduced by 24 [9 to 53]% below 2019 levels by 2030 and by
37 [20 to 60]% in 2040 in modelled pathways that limit warming to
2°C with action starting in 2020 (>67%) (high confidence). {WGIII SPM
C1.2, WGIII Table SPM.2, WGIII 3.3; SR1.5 SPM C.1, SR1.5 SPM C.1.2}
(Cross-Section Box.2)
All global modelled pathways that limit warming to 2°C (>67%)
or lower by 2100 involve GHG emission reductions in all sectors
(high confidence). The contributions of different sectors vary across
modelled mitigation pathways. In most global modelled mitigation
pathways, emissions from land-use, land-use change and forestry, via
reforestation and reduced deforestation, and from the energy supply
sector reach net zero CO2 emissions earlier than the buildings, industry
and transport sectors (Figure 4.1). Strategies can rely on combinations
of different options (Figure 4.1, Section 4.5), but doing less in one
sector needs to be compensated by further reductions in other sectors if
warming is to be limited. |
The contributions of different sectors vary across
modelled mitigation pathways. In most global modelled mitigation
pathways, emissions from land-use, land-use change and forestry, via
reforestation and reduced deforestation, and from the energy supply
sector reach net zero CO2 emissions earlier than the buildings, industry
and transport sectors (Figure 4.1). Strategies can rely on combinations
of different options (Figure 4.1, Section 4.5), but doing less in one
sector needs to be compensated by further reductions in other sectors if
warming is to be limited. (high confidence) {WGIII SPM C.3, WGIII SPM
C.3.1, WGIII SPM 3.2, WGIII SPM C.3.3} (Cross-Section Box.2)
Without rapid, deep and sustained mitigation and accelerated
adaptation actions, losses and damages will continue to
increase, including projected adverse impacts in Africa, LDCs,
SIDS, Central and South America147, Asia and the Arctic, and will
disproportionately affect the most vulnerable populations (high
confidence). {WGII SPM C.3.5, WGII SPM B.2.4, WGII 12.2, WGII 10.
Box 10.6, WGII TS D.7.5, WGII Cross-Chapter Box 6 ES, WGII Global
to Regional Atlas Annex A1.15, WGII Global to Regional Atlas Annex
A1.27; SR1.5 SPM B.5.3, SR 1.5 SPM B.5.7; SRCCL A.5.6} (Figure 3.2;
Figure 3.3)
147 The southern part of Mexico is included in the climatic subregion South Central America (SCA) for WGI. Mexico is assessed as part of North America for WGII. The climate change
literature for the SCA region occasionally includes Mexico, and in those cases WGII assessment makes reference to Latin America. Mexico is considered part of Latin America and
the Caribbean for WGIII. {WGII 12.1.1, WGIII AII.1.1} |
94
Section 4
Section 1
Section 4
a) Sectoral emissions in pathways that limit warming to 1.5°C
b) Greenhouse gas emissions by sector at
the time of net zero CO2, compared to 2019
The transition towards net zero CO2 will
have different pace across different sectors
CO2 emissions from the electricity/fossil fuel industries sector and
land-use change generally reach net zero earlier than other sectors
includes halting
deforestation
Percentage reduction in CO2 emissions relative to 2015
includes
decarbonised
electricity supply
Transport, industry
and buildings
Energy supply
(including electricity)
Non-CO2 emissions
Land-use
change
Key
Pathways consistent with limiting
warming to 1.5°C or 2°C by 2100
IMP-GS
IMP-Neg*
IMP-LD
IMP-SP
IMP-Ren
Gradual strengthening
High reliance on net negative emissions
High reliance on efficient resource use
Focus on sustainable development
Focus on renewables
Transport, industry and buildings
Non-CO2 emissions
Land-use change and forestry
Energy supply (including electricity)
*High overshoot
pathways to 2°C also reach net zero CO2
GHG emissions
(GtCO2-eq/yr)
Sources
Sinks
0
2020
2030
2040
2050
−125%
−100%
−75%
−25%
0%
net zero
halfway
to net zero
pathways for
2°C reach net zero
somewhat later
−20
20
40
60
2019
comparison
IMP-Neg
IMP-GS
IMP-Ren
IMP-LD
IMP-SP
these are different
ways to achieve
net zero CO2
Illustrative Mitigation
Pathways (IMPs)
net zero |
95
Near-Term Responses in a Changing Climate
Section 4
4.2 Benefits of Strengthening Near-Term Action
Figure 4.1: Sectoral emissions in pathways that limit warming to 1.5°C. Panel (a) shows sectoral CO2 and non-CO2 emissions in global modelled pathways that limit
warming to 1.5°C (>50%) with no or limited overshoot. The horizontal lines illustrate halving 2015 emissions (base year of the pathways) (dashed) and reaching net zero emissions
(solid line). The range shows the 5–95th percentile of the emissions across the pathways. The timing strongly differs by sector, with the CO2 emissions from the electricity/fossil fuel
industries sector and land-use change generally reaching net zero earlier. Non-CO2 emissions from agriculture are also substantially reduced compared to pathways without climate
policy but do not typically reach zero. Panel (b) Although all pathways include strongly reduced emissions, there are different pathways as indicated by the illustrative mitigation
pathways used in IPCC WGIII. The pathways emphasise routes consistent with limiting warming to 1.5°C with a high reliance on net negative emissions (IMP-Neg), high resource
efficiency (IMP-LD), a focus on sustainable development (IMP-SP) or renewables (IMP-Ren) and consistent with 2°C based on a less rapid introduction of mitigation measures followed
by a subsequent gradual strengthening (IMP-GS). Positive (solid filled bars) and negative emissions (hatched bars) for different illustrative mitigation pathways are compared to
GHG emissions from the year 2019. The category “energy supply (including electricity)” includes bioenergy with carbon capture and storage and direct air carbon capture and storage.
{WGIII Box TS.5, WGIII 3.3, WGIII 3.4, WGIII 6.6, WGIII 10.3, WGIII 11.3} (Cross-Section Box.2)
Accelerated implementation of adaptation will improve well-being by reducing losses and damages, especially
for vulnerable populations. |
Positive (solid filled bars) and negative emissions (hatched bars) for different illustrative mitigation pathways are compared to
GHG emissions from the year 2019. The category “energy supply (including electricity)” includes bioenergy with carbon capture and storage and direct air carbon capture and storage.
{WGIII Box TS.5, WGIII 3.3, WGIII 3.4, WGIII 6.6, WGIII 10.3, WGIII 11.3} (Cross-Section Box.2)
Accelerated implementation of adaptation will improve well-being by reducing losses and damages, especially
for vulnerable populations. Deep, rapid, and sustained mitigation actions would reduce future adaptation costs
and losses and damages, enhance sustainable development co-benefits, avoid locking-in emission sources,
and reduce stranded assets and irreversible climate changes. These near-term actions involve higher up-front
investments and disruptive changes, which can be moderated by a range of enabling conditions and removal or
reduction of barriers to feasibility. (high confidence)
Accelerated implementation of adaptation responses will bring
benefits to human well-being (high confidence) (Section 4.3). As
adaptation options often have long implementation times, long-term
planning and accelerated implementation, particularly in this decade, is
important to close adaptation gaps, recognising that constraints remain
for some regions. The benefits to vulnerable populations would be high
(see Section 4.4). |
Deep, rapid, and sustained mitigation actions would reduce future adaptation costs
and losses and damages, enhance sustainable development co-benefits, avoid locking-in emission sources,
and reduce stranded assets and irreversible climate changes. These near-term actions involve higher up-front
investments and disruptive changes, which can be moderated by a range of enabling conditions and removal or
reduction of barriers to feasibility. (high confidence)
Accelerated implementation of adaptation responses will bring
benefits to human well-being (high confidence) (Section 4.3). As
adaptation options often have long implementation times, long-term
planning and accelerated implementation, particularly in this decade, is
important to close adaptation gaps, recognising that constraints remain
for some regions. The benefits to vulnerable populations would be high
(see Section 4.4). (high confidence) {WGI SPM B.1, WGI SPM B.1.3, WGI
SPM B.2.2, WGI SPM B.3; WGII SPM C.1.1, WGII SPM C.1.2, WGII SPM
C.2, WGII SPM C.3.1, WGII Figure SPM.4b; SROCC SPM C.3.4, SROCC
Figure 3.4, SROCC Figure SPM.5}
Near-term actions that limit global warming to close to 1.5°C
would substantially reduce projected losses and damages related
to climate change in human systems and ecosystems, compared
to higher warming levels, but cannot eliminate them all (very
high confidence). The magnitude and rate of climate change and
associated risks depend strongly on near-term mitigation and adaptation
actions, and projected adverse impacts and related losses and damages
escalate with every increment of global warming (very high confidence).
Delayed mitigation action will further increase global warming which
will decrease the effectiveness of many adaptation options, including
Ecosystem-based Adaptation and many water-related options, as well
as increasing mitigation feasibility risks, such as for options based on
ecosystems (high confidence). |
The magnitude and rate of climate change and
associated risks depend strongly on near-term mitigation and adaptation
actions, and projected adverse impacts and related losses and damages
escalate with every increment of global warming (very high confidence).
Delayed mitigation action will further increase global warming which
will decrease the effectiveness of many adaptation options, including
Ecosystem-based Adaptation and many water-related options, as well
as increasing mitigation feasibility risks, such as for options based on
ecosystems (high confidence). Comprehensive, effective, and innovative
responses integrating adaptation and mitigation can harness synergies
and reduce trade-offs between adaptation and mitigation, as well as in
meeting requirements for financing (very high confidence) (see Section
4.5, 4.6, 4.8 and 4.9). {WGII SPM B.3, WGII SPM B.4, WGII SPM B.6.2,
WGII SPM C.2, WGII SPM C.3, WGII SPM D.1, WGII SPM D.4.3, WGII SPM D.5,
WG II TS D.1.4, WG II TS.D.5, WGII TS D.7.5; WGIII SPM B.6.3,WGIII SPM B.6.4,
WGIII SPM C.9, WGIII SPM D.2, WGIII SPM E.13; SR1.5 SPM C.2.7,
SR1.5 D.1.3, SR1.5 D.5.2}
Mitigation actions will have other sustainable development
co-benefits (high confidence). Mitigation will improve air quality and
human health in the near term notably because many air pollutants are
148 In this context, ‘unabated fossil fuels’ refers to fossil fuels produced and used without interventions that substantially reduce the amount of GHG emitted throughout the life
cycle; for example, capturing 90% or more CO2 from power plants, or 50 to 80% of fugitive methane emissions from energy supply. |
Mitigation will improve air quality and
human health in the near term notably because many air pollutants are
148 In this context, ‘unabated fossil fuels’ refers to fossil fuels produced and used without interventions that substantially reduce the amount of GHG emitted throughout the life
cycle; for example, capturing 90% or more CO2 from power plants, or 50 to 80% of fugitive methane emissions from energy supply. {WGIII SPM footnote 54}
co-emitted by GHG emitting sectors and because methane emissions
leads to surface ozone formation (high confidence). The benefits from
air quality improvement include prevention of air pollution-related
premature deaths, chronic diseases and damages to ecosystems
and crops. The economic benefits for human health from air quality
improvement arising from mitigation action can be of the same order
of magnitude as mitigation costs, and potentially even larger (medium
confidence). As methane has a short lifetime but is a potent GHG,
strong, rapid and sustained reductions in methane emissions can limit
near-term warming and improve air quality by reducing global surface
ozone (high confidence). {WGI SPM D.1.7, WGI SPM D.2.2, WGI 6.7,
WGI TS Box TS.7, WGI 6 Box 6.2, WGI Figure 6.3, WGI Figure 6.16,
WGI Figure 6.17; WGII TS.D.8.3, WGII Cross-Chapter Box HEALTH,
WGII 5 ES, WGII 7 ES; WGII 7.3.1.2; WGIII Figure SPM.8, WGIII SPM
C.2.3, WGIII SPM C.4.2, WGIII TS.4.2}
Challenges from delayed adaptation and mitigation actions
include the risk of cost escalation, lock-in of infrastructure,
stranded assets, and reduced feasibility and effectiveness
of adaptation and mitigation options (high confidence). The
continued installation of unabated fossil fuel148 infrastructure
will ‘lock-in’ GHG emissions (high confidence). |
The
continued installation of unabated fossil fuel148 infrastructure
will ‘lock-in’ GHG emissions (high confidence). Limiting global
warming to 2°C or below will leave a substantial amount of fossil fuels
unburned and could strand considerable fossil fuel infrastructure
(high confidence), with globally discounted value projected to be
around USD 1 to 4 trillion from 2015 to 2050 (medium confidence).
Early actions would limit the size of these stranded assets, whereas
delayed actions with continued investments in unabated high-emitting
infrastructure and limited development and deployment of low-emitting
alternatives prior to 2030 would raise future stranded assets to the
higher end of the range – thereby acting as barriers and increasing
political economy feasibility risks that may jeopardise efforts to limit
global warming. (high confidence). {WGIII SPM B.6.3, WGIII SPM C.4,
WGIII Box TS.8} |
96
Section 4
Section 1
Section 4
Scaling-up near-term climate actions (Section 4.1) will mobilise a
mix of low-cost and high-cost options. High-cost options, as in energy
and infrastructure, are needed to avoid future lock-ins, foster innovation
and initiate transformational changes (Figure 4.4). Climate resilient
development pathways in support of sustainable development for all are
shaped by equity, and social and climate justice (very high confidence).
Embedding effective and equitable adaptation and mitigation in
development planning can reduce vulnerability, conserve and restore
ecosystems, and enable climate resilient development. This is especially
challenging in localities with persistent development gaps and limited
resources. (high confidence) {WGII SPM C.5, WGII SPM D1; WGIII TS.5.2,
WGIII 8.3.1, WGIII 8.3.4, WGIII 8.4.1, WGIII 8.6}
Scaling-up climate action may generate disruptive changes in
economic structure with distributional consequences and need
to reconcile divergent interests, values and worldviews, within
and between countries. Deeper fiscal, financial, institutional and
regulatory reforms can offset such adverse effects and unlock mitigation
potentials. Societal choices and actions implemented in this decade will
determine the extent to which medium and long-term development
pathways will deliver higher or lower climate resilient development
outcomes. (high confidence) {WGII SPM D.2, WGII SPM D.5, WGII Box TS.8;
WGIII SPM D.3, WGIII SPM E.2, WGIII SPM E.3, WGIII SPM E.4, WGIII TS.2,
WGIII TS.4.1, WGIII TS.6.4, WGIII 15.2, WGIII 15.6}
Enabling conditions would need to be strengthened in the near-
term and barriers reduced or removed to realise opportunities
for deep and rapid adaptation and mitigation actions and
climate resilient development (high confidence) (Figure 4.2). |
Societal choices and actions implemented in this decade will
determine the extent to which medium and long-term development
pathways will deliver higher or lower climate resilient development
outcomes. (high confidence) {WGII SPM D.2, WGII SPM D.5, WGII Box TS.8;
WGIII SPM D.3, WGIII SPM E.2, WGIII SPM E.3, WGIII SPM E.4, WGIII TS.2,
WGIII TS.4.1, WGIII TS.6.4, WGIII 15.2, WGIII 15.6}
Enabling conditions would need to be strengthened in the near-
term and barriers reduced or removed to realise opportunities
for deep and rapid adaptation and mitigation actions and
climate resilient development (high confidence) (Figure 4.2).
These enabling conditions are differentiated by national, regional
and local circumstances and geographies, according to capabilities,
and include: equity and inclusion in climate action (see Section 4.4),
rapid and far-reaching transitions in sectors and system (see Section
4.5), measures to achieve synergies and reduce trade-
offs with sustainable development goals (see Section 4.6),
governance and policy improvements (see Section 4.7), access
to finance, improved international cooperation and technology
improvements (see Section 4.8), and integration of near-term
actions across sectors, systems and regions (see Section 4.9).
{WGII SPM D.2; WGIII SPM E.1, WGIII SPM E.2}
Barriers to feasibility would need to be reduced or removed
to deploy mitigation and adaptation options at scale. Many
limits to feasibility and effectiveness of responses can be overcome
by addressing a range of barriers, including economic, technological,
institutional, social, environmental and geophysical barriers. The
feasibility and effectiveness of options increase with integrated,
multi-sectoral solutions that differentiate responses based on climate
risk, cut across systems and address social inequities. |
{WGII SPM D.2; WGIII SPM E.1, WGIII SPM E.2}
Barriers to feasibility would need to be reduced or removed
to deploy mitigation and adaptation options at scale. Many
limits to feasibility and effectiveness of responses can be overcome
by addressing a range of barriers, including economic, technological,
institutional, social, environmental and geophysical barriers. The
feasibility and effectiveness of options increase with integrated,
multi-sectoral solutions that differentiate responses based on climate
risk, cut across systems and address social inequities. Strengthened
near-term actions in modelled cost-effective pathways that limit global
warming to 2°C or lower, reduce the overall risk to the feasibility of the
system transitions, compared to modelled pathways with delayed or
uncoordinated action. (high confidence) {WGII SPM C.2, WGII SPM C.3,
WGII SPM C.5; WGIII SPM E.1, WGIII SPM E.1.3}
Integrating ambitious climate actions with macroeconomic
policies under global uncertainty would provide benefits
(high confidence). This encompasses three main directions:
(a) economy-wide mainstreaming packages supporting options to
improved sustainable low-emission economic recovery, development
and job creation programs (Sections 4.4, 4.5, 4.6, 4.8, 4.9) (b) safety
nets and social protection in the transition (Section 4.4, 4.7); and
(c) broadened access to finance, technology and capacity-building
and coordinated support to low-emission infrastructure (‘leap-frog’
potential), especially in developing regions, and under debt stress
(high confidence). |
This encompasses three main directions:
(a) economy-wide mainstreaming packages supporting options to
improved sustainable low-emission economic recovery, development
and job creation programs (Sections 4.4, 4.5, 4.6, 4.8, 4.9) (b) safety
nets and social protection in the transition (Section 4.4, 4.7); and
(c) broadened access to finance, technology and capacity-building
and coordinated support to low-emission infrastructure (‘leap-frog’
potential), especially in developing regions, and under debt stress
(high confidence). (Section 4.8) {WGII SPM C.2, WGII SPM C.4.1,
WGII SPM D.1.3, WGII SPM D.2, WGII SPM D.3.2, WGII SPM E.2.2,
WGII SPM E.4, WGII SPM TS.2, WGII SPM TS.5.2, WGII TS.6.4,
WGII TS.15, WGII TS Box TS.3; WGIII SPM B.4.2, WGIII SPM C.5.4,
WGIII SPM C.6.2, WGIII SPM C.12.2, WGIII SPM D.3.4, WGIII SPM E.4.2,
WGIII SPM E.4.5, WGIII SPM E.5.2, WGIII SPM E.5.3, WGIII TS.1, WGIII Box TS.15,
WGIII 15.2, WGIII Cross-Chapter Box 1 on COVID in Chapter 1} |
97
Near-Term Responses in a Changing Climate
Section 4
Climate Resilient Development
Emissions reductions
Adaptation
Sustainable Development
Multiple interacting choices and actions can shift
development pathways towards sustainability
Sustainable Development
Goal (SDG) achievement
IPCC AR6
2030
Present
world
Past
conditions
There is a rapidly narrowing window of opportunity
to enable climate resilient development
Prospects for climate
resilient development will
be further limited if global
warming exceeds 1.5°C and
if progress towards the SDGs
is inadequate
Early action and enabling
conditions create future
opportunities for climate
resilient development
Past conditions
(emissions, climate
change, development)
have increased warming
and development gaps persist
opportunit
ies mi
ssed
Illustrative ‘shock’ that
disrupts development
warming limited to be
low 1.5°
C
Low emissions
System transitions
Transformation
Low climate risk
Equity and justice
SDG achievement
High emissions
Entrenched systems
Adaptation limits
Maladaptation
Increasing climate risk
Reduced options
for development
Ecosystem
degradation
Outcomes characterising
development pathways
Civil
society
Governments
Private
sector
Conditions that enable
individual and collective actions
• Inclusive governance
• Diverse knowledges and values
• Finance and innovation
• Integration across sectors
and time scales
• Ecosystem stewardship
• Synergies between climate
and development actions
• Behavioural change supported
by policy, infrastructure and
socio-cultural factors
Conditions that constrain
individual and collective actions
• Poverty, inequity and injustice
• Economic, institutional, social
and capacity barriers
• Siloed responses
• Lack of finance, and barriers
to finance and technology
• Tradeoffs with SDGs
2100
& beyond
Figure 4.2: The illustrative development pathways (red to green) and associated outcomes (right panel) show that there is a rapidly narrowing window of
opportunity to secure a liveable and sustainable future for all. Climate resilient development is the process of implementing greenhouse gas mitigation and adaptation
measures to support sustainable development. |
Climate resilient development is the process of implementing greenhouse gas mitigation and adaptation
measures to support sustainable development. Diverging pathways illustrate that interacting choices and actions made by diverse government, private sector and civil society actors
can advance climate resilient development, shift pathways towards sustainability, and enable lower emissions and adaptation. Diverse knowledges and values include cultural values,
Indigenous Knowledge, local knowledge, and scientific knowledge. Climatic and non-climatic events, such as droughts, floods or pandemics, pose more severe shocks to pathways
with lower climate resilient development (red to yellow) than to pathways with higher climate resilient development (green). There are limits to adaptation and adaptive capacity
for some human and natural systems at global warming of 1.5°C, and with every increment of warming, losses and damages will increase. The development pathways taken by
countries at all stages of economic development impact GHG emissions and hence shape mitigation challenges and opportunities, which vary across countries and regions.
Pathways and opportunities for action are shaped by previous actions (or inactions and opportunities missed, dashed pathway), and enabling and constraining conditions
(left panel), and take place in the context of climate risks, adaptation limits and development gaps. The longer emissions reductions are delayed, the fewer effective
adaptation options. |
Climatic and non-climatic events, such as droughts, floods or pandemics, pose more severe shocks to pathways
with lower climate resilient development (red to yellow) than to pathways with higher climate resilient development (green). There are limits to adaptation and adaptive capacity
for some human and natural systems at global warming of 1.5°C, and with every increment of warming, losses and damages will increase. The development pathways taken by
countries at all stages of economic development impact GHG emissions and hence shape mitigation challenges and opportunities, which vary across countries and regions.
Pathways and opportunities for action are shaped by previous actions (or inactions and opportunities missed, dashed pathway), and enabling and constraining conditions
(left panel), and take place in the context of climate risks, adaptation limits and development gaps. The longer emissions reductions are delayed, the fewer effective
adaptation options. {WGI SPM B.1; WGII SPM B.1 to B.5, WGII SPM C.2 to 5, WGII SPM D.1 to 5, WGII Figure SPM.3, WGII Figure SPM.4, WGII Figure SPM.5, WGII TS.D.5, WGII 3.1,
WGII 3.2, WGII 3.4, WGII 4.2, WGII Figure 4.4, WGII 4.5, WGII 4.6, WGII 4.9; WGIII SPM A, WGIII SPM B1, WGIII SPM B.3, WGIII SPM B.6, WGIII SPM C.4, WGIII SPM D1 to 3,
WGIII SPM E.1, WGIII SPM E.2, WGIII SPM E.4, WGIII SPM E.5, WGIII Figure TS.1, WGIII Figure TS.7, WGIII Box TS.3, WGIII Box TS.8, Cross-Working Group Box 1 in Chapter 3,
WGIII Cross-Chapter Box 5 in Chapter 4; SR1.5 SPM D.1 to 6; SRCCL SPM D.3}
4.3 Near-Term Risks
Many changes in the climate system, including extreme events, will become larger in the near term with increasing
global warming (high confidence). |
Multiple climatic and non-climatic risks will interact, resulting in increased
compounding and cascading impacts becoming more difficult to manage (high confidence). Losses and damages
will increase with increasing global warming (very high confidence), while strongly concentrated among the
poorest vulnerable populations (high confidence). Continuing with current unsustainable development patterns
would increase exposure and vulnerability of ecosystems and people to climate hazards (high confidence). |
98
Section 4
Section 1
Section 4
Global warming will continue to increase in the near term (2021–2040)
mainly due to increased cumulative CO2 emissions in nearly all
considered scenarios and pathways. In the near term, every
region in the world is projected to face further increases in
climate hazards (medium to high confidence, depending on
region and hazard), increasing multiple risks to ecosystems
and humans (very high confidence). In the near term, natural
variability149 will modulate human-caused changes, either attenuating
or amplifying projected changes, especially at regional scales, with little
effect on centennial global warming. Those modulations are important
to consider in adaptation planning. Global surface temperature in any
single year can vary above or below the long-term human-induced
trend, due to natural variability. By 2030, global surface temperature
in any individual year could exceed 1.5°C relative to 1850–1900 with a
probability between 40% and 60%, across the five scenarios assessed
in WGI (medium confidence). The occurrence of individual years with
global surface temperature change above a certain level does not
imply that this global warming level has been reached. If a large
explosive volcanic eruption were to occur in the near term150 , it
would temporarily and partially mask human-caused climate change
by reducing global surface temperature and precipitation, especially
over land, for one to three years (medium confidence). {WGI SPM B.1.3,
WGI SPM B.1.4, WGI SPM C.1, WGI SPM C.2, WGI Cross-Section Box TS.1,
WGI Cross-Chapter Box 4.1; WGII SPM B.3, WGII SPM B.3.1;
WGIII Box SPM.1 Figure 1}
The level of risk for humans and ecosystems will depend on near-term
trends in vulnerability, exposure, level of socio-economic
development and adaptation (high confidence). |
If a large
explosive volcanic eruption were to occur in the near term150 , it
would temporarily and partially mask human-caused climate change
by reducing global surface temperature and precipitation, especially
over land, for one to three years (medium confidence). {WGI SPM B.1.3,
WGI SPM B.1.4, WGI SPM C.1, WGI SPM C.2, WGI Cross-Section Box TS.1,
WGI Cross-Chapter Box 4.1; WGII SPM B.3, WGII SPM B.3.1;
WGIII Box SPM.1 Figure 1}
The level of risk for humans and ecosystems will depend on near-term
trends in vulnerability, exposure, level of socio-economic
development and adaptation (high confidence). In the near term,
many climate-associated risks to natural and human systems depend
more strongly on changes in these systems’ vulnerability and exposure
than on differences in climate hazards between emissions scenarios
(high confidence). Future exposure to climatic hazards is increasing
globally due to socio-economic development trends including growing
inequality, and when urbanisation or migration increase exposure
(high confidence). Urbanisation increases hot extremes (very high
confidence) and precipitation runoff intensity (high confidence).
Increasing urbanisation in low-lying and coastal zones will be a major
driver of increasing exposure to extreme riverflow events and sea level
rise hazards, increasing risks (high confidence) (Figure 4.3). Vulnerability
will also rise rapidly in low-lying Small Island Developing States and
atolls in the context of sea level rise (high confidence) (see Figure 3.4 and
Figure 4.3). Human vulnerability will concentrate in informal settlements
and rapidly growing smaller settlements; and vulnerability in rural
areas will be heightened by reduced habitability and high reliance on
climate-sensitive livelihoods (high confidence). Human and ecosystem
vulnerability are interdependent (high confidence). |
Urbanisation increases hot extremes (very high
confidence) and precipitation runoff intensity (high confidence).
Increasing urbanisation in low-lying and coastal zones will be a major
driver of increasing exposure to extreme riverflow events and sea level
rise hazards, increasing risks (high confidence) (Figure 4.3). Vulnerability
will also rise rapidly in low-lying Small Island Developing States and
atolls in the context of sea level rise (high confidence) (see Figure 3.4 and
Figure 4.3). Human vulnerability will concentrate in informal settlements
and rapidly growing smaller settlements; and vulnerability in rural
areas will be heightened by reduced habitability and high reliance on
climate-sensitive livelihoods (high confidence). Human and ecosystem
vulnerability are interdependent (high confidence). Vulnerability to
climate change for ecosystems will be strongly influenced by past,
present, and future patterns of human development, including from
unsustainable consumption and production, increasing demographic
pressures, and persistent unsustainable use and management of
149 See Annex I: Glossary. The main internal variability phenomena include El Niño–Southern Oscillation, Pacific Decadal Variability and Atlantic Multi-decadal Variability through
their regional influence. The internal variability of global surface temperature in any single year is estimated to be about ±0.25°C (5 to 95% range, high confidence).
{WGI SPM footnote 29, WGI SPM footnote 37}
150 Based on 2500-year reconstructions, eruptions with a radiative forcing more negative than –1 Wm-2, related to the radiative effect of volcanic stratospheric aerosols in the
literature assessed in this report, occur on average twice per century. {WGI SPM footnote 38}
land, ocean, and water (high confidence). Several near-term risks can
be moderated with adaptation (high confidence). |
The main internal variability phenomena include El Niño–Southern Oscillation, Pacific Decadal Variability and Atlantic Multi-decadal Variability through
their regional influence. The internal variability of global surface temperature in any single year is estimated to be about ±0.25°C (5 to 95% range, high confidence).
{WGI SPM footnote 29, WGI SPM footnote 37}
150 Based on 2500-year reconstructions, eruptions with a radiative forcing more negative than –1 Wm-2, related to the radiative effect of volcanic stratospheric aerosols in the
literature assessed in this report, occur on average twice per century. {WGI SPM footnote 38}
land, ocean, and water (high confidence). Several near-term risks can
be moderated with adaptation (high confidence). {WGI SPM C.2.6;
WGII SPM B.2, WGII SPM B.2.3, WGII SPM B.2.5, WGII SPM B.3,
WGII SPM B.3.2, WGII TS.C.5.2} (Section 4.5 and 3.2)
Principal hazards and associated risks expected in the near term
(at 1.5°C global warming) are:
• Increased intensity and frequency of hot extremes and dangerous
heat-humidity conditions, with increased human mortality, morbidity,
and labour productivity loss (high confidence). {WGI SPM B.2.2,
WGI TS Figure TS.6; WGII SPM B.1.4, WGII SPM B.4.4,
WGII Figure SPM.2}
• Increasing frequency of marine heatwaves will increase risks
of biodiversity loss in the oceans, including from mass mortality
events (high confidence). |
{WGI SPM B.2.2,
WGI TS Figure TS.6; WGII SPM B.1.4, WGII SPM B.4.4,
WGII Figure SPM.2}
• Increasing frequency of marine heatwaves will increase risks
of biodiversity loss in the oceans, including from mass mortality
events (high confidence). {WGI SPM B.2.3; WGII SPM B.1.2,
WGII Figure SPM.2; SROCC SPM B.5.1}
• Near-term risks for biodiversity loss are moderate to high in
forest ecosystems (medium confidence) and kelp and seagrass
ecosystems (high to very high confidence) and are high to very
high in Arctic sea-ice and terrestrial ecosystems (high confidence)
and warm-water coral reefs (very high confidence). {WGII SPM B.3.1}
• More intense and frequent extreme rainfall and associated flooding
in many regions including coastal and other low-lying cities
(medium to high confidence), and increased proportion of and
peak wind speeds of intense tropical cyclones (high confidence).
{WGI SPM B.2.4, WGI SPM C.2.2, WGI SPM C.2.6, WGI 11.7}
• High risks from dryland water scarcity, wildfire damage, and
permafrost degradation (medium confidence). {SRCCL SPM A.5.3.}
• Continued sea level rise and increased frequency and
magnitude of extreme sea level events encroaching on coastal
human settlements and damaging coastal infrastructure (high
confidence), committing low-lying coastal ecosystems to
submergence and loss (medium confidence), expanding land
salinization (very high confidence), with cascading to risks to
livelihoods, health, well-being, cultural values, food and water
security (high confidence). |
{WGI SPM B.2.4, WGI SPM C.2.2, WGI SPM C.2.6, WGI 11.7}
• High risks from dryland water scarcity, wildfire damage, and
permafrost degradation (medium confidence). {SRCCL SPM A.5.3.}
• Continued sea level rise and increased frequency and
magnitude of extreme sea level events encroaching on coastal
human settlements and damaging coastal infrastructure (high
confidence), committing low-lying coastal ecosystems to
submergence and loss (medium confidence), expanding land
salinization (very high confidence), with cascading to risks to
livelihoods, health, well-being, cultural values, food and water
security (high confidence). {WGI SPM C.2.5, WGI SPM C.2.6;
WGII SPM B.3.1, WGII SPM B.5.2; SRCCL SPM A.5.6; SROCC SPM B.3.4,
SROCC SPM 3.6, SROCC SPM B.9.1} (Figure 3.4, 4.3)
• Climate change will significantly increase ill health and premature
deaths from the near to long term (high confidence). Further
warming will increase climate-sensitive food-borne, water-borne,
and vector-borne disease risks (high confidence), and mental health
challenges including anxiety and stress (very high confidence).
{WGII SPM B.4.4} |
99
Near-Term Responses in a Changing Climate
Section 4
• Cryosphere-related changes in floods, landslides, and water
availability have the potential to lead to severe consequences for
people, infrastructure and the economy in most mountain regions
(high confidence). {WGII TS C.4.2}
• The projected increase in frequency and intensity of heavy
precipitation (high confidence) will increase rain-generated local
flooding (medium confidence). {WGI Figure SPM.6, WGI SPM B.2.2;
WGII TS C.4.5}
Multiple climate change risks will increasingly compound and
cascade in the near term (high confidence). Many regions are
projected to experience an increase in the probability of compound
events with higher global warming (high confidence) including
concurrent heatwaves and drought. Risks to health and food
production will be made more severe from the interaction of sudden
food production losses from heat and drought, exacerbated by heat-
induced labour productivity losses (high confidence) (Figure 4.3). These
interacting impacts will increase food prices, reduce household incomes,
and lead to health risks of malnutrition and climate-related mortality
with no or low levels of adaptation, especially in tropical regions (high
confidence). Concurrent and cascading risks from climate change to
food systems, human settlements, infrastructure and health will make
these risks more severe and more difficult to manage, including when
interacting with non-climatic risk drivers such as competition for land
between urban expansion and food production, and pandemics (high
confidence). Loss of ecosystems and their services has cascading and
long-term impacts on people globally, especially for Indigenous Peoples
and local communities who are directly dependent on ecosystems, to
meet basic needs (high confidence). |
These
interacting impacts will increase food prices, reduce household incomes,
and lead to health risks of malnutrition and climate-related mortality
with no or low levels of adaptation, especially in tropical regions (high
confidence). Concurrent and cascading risks from climate change to
food systems, human settlements, infrastructure and health will make
these risks more severe and more difficult to manage, including when
interacting with non-climatic risk drivers such as competition for land
between urban expansion and food production, and pandemics (high
confidence). Loss of ecosystems and their services has cascading and
long-term impacts on people globally, especially for Indigenous Peoples
and local communities who are directly dependent on ecosystems, to
meet basic needs (high confidence). Increasing transboundary risks
are projected across the food, energy and water sectors as impacts
from weather and climate extremes propagate through supply-chains,
markets, and natural resource flows (high confidence) and may interact
with impacts from other crises such as pandemics. Risks also arise from
some responses intended to reduce the risks of climate change, including
risks from maladaptation and adverse side effects of some emissions
reduction and carbon dioxide removal measures, such as afforestation of
naturally unforested land or poorly implemented bioenergy compounding
climate-related risks to biodiversity, food and water security, and
livelihoods (high confidence) (see Section 3.4.1 and 4.5). |
Increasing transboundary risks
are projected across the food, energy and water sectors as impacts
from weather and climate extremes propagate through supply-chains,
markets, and natural resource flows (high confidence) and may interact
with impacts from other crises such as pandemics. Risks also arise from
some responses intended to reduce the risks of climate change, including
risks from maladaptation and adverse side effects of some emissions
reduction and carbon dioxide removal measures, such as afforestation of
naturally unforested land or poorly implemented bioenergy compounding
climate-related risks to biodiversity, food and water security, and
livelihoods (high confidence) (see Section 3.4.1 and 4.5). {WGI SPM.2.7;
WGII SPM B.2.1, WGII SPM B.5, WGII SPM B.5.1, WGII SPM B.5.2,
WGII SPM B.5.3, WGII SPM B.5.4, WGII Cross-Chapter Box COVID in Chapter 7;
WGIII SPM C.11.2; SRCCL SPM A.5, SRCCL SPM A.6.5} (Figure 4.3)
With every increment of global warming losses and damages will
increase (very high confidence), become increasingly difficult
to avoid and be strongly concentrated among the poorest
vulnerable populations (high confidence). Adaptation does not
prevent all losses and damages, even with effective adaptation and
before reaching soft and hard limits. Losses and damages will be
unequally distributed across systems, regions and sectors and are
not comprehensively addressed by current financial, governance and
institutional arrangements, particularly in vulnerable developing
countries. (high confidence). {WGII SPM B.4, WGII SPM C.3, WGII SPM C.3.5} |
100
Section 4
Section 1
Section 4
absolute increase
(and percent increase)
Every region faces more severe and/or frequent compound
and cascading climate risks
a) Increase in the population exposed to sea level rise from 2020 to 2040
Frequency of events that currently occur
on average once every 100 years
Multiple climate change risks
will increasingly compound
and cascade in the near term
c) Example of complex risk, where impacts from climate extreme events have cascading
effects on food, nutrition, livelihoods and well-being of smallholder farmers
Food yield
and quality losses
Food prices
increase
Reduced labour
capacity
Reduced
food security
Decreased
quality of life
Increased malnutrition
(particularly maternal malnutrition
and child undernutrition)
Reduced soil moisture
and health
Bi-directional
compounding
Uni-directional
compounding or domino
Contagion effect on
multiple risks
Reduced household
income
Key
Extreme heat and drought
Exposure to a coastal flooding event that
currently occurs on average once every 100 years
More frequent and more intense
Annual event
Twice-a-century event
No change
Decadal event
b) Increased frequency of extreme
sea level events by 2040
Africa
Asia
Australasia
Central and
South America
Europe
North America
Small Islands
0.10 million (57%)
0.18 million
0.34 million
0.69 million
2.40 million
0.38 million (57%)
0.67 million
63.81 million
0.01 million (52%)
0.02 million
16.36 million (26%)
2.29 million (95%)
0.24 million (35%)
0.24 million (71%)
+
+
+
+
+
+
+
Increase due to sea level rise only
Increase due to sea level rise and population change
Population exposed in 2020
SSP2-4.5
Additional population exposed in 2040
0.1
million
1
million
The absence of a circle indicates an inability to perform
an assessment due to a lack of data. |
Projected change to
1-in-100 year events
under the intermediate
SSP2-4.5 scenario |
101
Near-Term Responses in a Changing Climate
Section 4
Figure 4.3: Every region faces more severe or frequent compound and/or cascading climate risks in the near term. Changes in risk result from changes in the degree
of the hazard, the population exposed, and the degree of vulnerability of people, assets, or ecosystems. Panel (a) Coastal flooding events affect many of the highly populated regions
of the world where large percentages of the population are exposed. The panel shows near-term projected increase of population exposed to 100-year flooding events depicted
as the increase from the year 2020 to 2040 (due to sea level rise and population change), based on the intermediate GHG emissions scenario (SSP2-4.5) and current adaptation
measures. Out-migration from coastal areas due to future sea level rise is not considered in the scenario. Panel (b) projected median probability in the year 2040 for extreme water
levels resulting from a combination of mean sea level rise, tides and storm surges, which have a historical 1% average annual probability. A peak-over-threshold (99.7%) method
was applied to the historical tide gauge observations available in the Global Extreme Sea Level Analysis version 2 database, which is the same information as WGI Figure 9.32,
except here the panel uses relative sea level projections under SSP2-4.5 for the year 2040 instead of 2050 The absence of a circle indicates an inability to perform an assessment
due to a lack of data, but does not indicate absence of increasing frequencies. Panel (c) Climate hazards can initiate risk cascades that affect multiple sectors and propagate across
regions following complex natural and societal connections. This example of a compound heat wave and a drought event striking an agricultural region shows how multiple risks are
interconnected and lead to cascading biophysical, economic, and societal impacts even in distant regions, with vulnerable groups such as smallholder farmers, children and pregnant
women particularly impacted. |
A peak-over-threshold (99.7%) method
was applied to the historical tide gauge observations available in the Global Extreme Sea Level Analysis version 2 database, which is the same information as WGI Figure 9.32,
except here the panel uses relative sea level projections under SSP2-4.5 for the year 2040 instead of 2050 The absence of a circle indicates an inability to perform an assessment
due to a lack of data, but does not indicate absence of increasing frequencies. Panel (c) Climate hazards can initiate risk cascades that affect multiple sectors and propagate across
regions following complex natural and societal connections. This example of a compound heat wave and a drought event striking an agricultural region shows how multiple risks are
interconnected and lead to cascading biophysical, economic, and societal impacts even in distant regions, with vulnerable groups such as smallholder farmers, children and pregnant
women particularly impacted. {WGI Figure 9.32; WGII SPM B4.3, WGII SPM B1.3, WGII SPM B.5.1, WGII TS Figure TS.9, WGII TS Figure TS.10 (c), WGII Fig 5.2, WGII TS.B.2.3,
WGII TS.B.2.3, WGII TS.B.3.3, WGII 9.11.1.2}
Actions that prioritise equity, climate justice, social justice and inclusion lead to more sustainable outcomes,
co-benefits, reduce trade-offs, support transformative change and advance climate resilient development.
Adaptation responses are immediately needed to reduce rising climate risks, especially for the most vulnerable.
Equity, inclusion and just transitions are key to progress on adaptation and deeper societal ambitions for
accelerated mitigation. (high confidence)
Adaptation and mitigation actions, across scales, sectors and
regions, that prioritise equity, climate justice, rights-based
approaches, social justice and inclusivity, lead to more
sustainable outcomes, reduce trade-offs, support transformative
change and advance climate resilient development (high
confidence). |
Adaptation responses are immediately needed to reduce rising climate risks, especially for the most vulnerable.
Equity, inclusion and just transitions are key to progress on adaptation and deeper societal ambitions for
accelerated mitigation. (high confidence)
Adaptation and mitigation actions, across scales, sectors and
regions, that prioritise equity, climate justice, rights-based
approaches, social justice and inclusivity, lead to more
sustainable outcomes, reduce trade-offs, support transformative
change and advance climate resilient development (high
confidence). Redistributive policies across sectors and regions that
shield the poor and vulnerable, social safety nets, equity, inclusion
and just transitions, at all scales can enable deeper societal ambitions
and resolve trade-offs with sustainable development goals.(SDGs),
particularly education, hunger, poverty, gender and energy access (high
confidence). Mitigation efforts embedded within the wider development
context can increase the pace, depth and breadth of emission reductions
(medium confidence). Equity, inclusion and just transitions at all
scales enable deeper societal ambitions for accelerated mitigation,
and climate action more broadly (high confidence). The complexity in
risk of rising food prices, reduced household incomes, and health and
climate-related malnutrition (particularly maternal malnutrition and
child undernutrition) and mortality increases with little or low levels
of adaptation (high confidence). {WGII SPM B.5.1, WGII SPM C.2.9,
WGII SPM D.2.1, WGII TS Box TS.4; WGIII SPM D.3, WGIII SPM D.3.3,
WGIII SPM WGIII SPM E.3, SR1.5 SPM D.4.5} (Figure 4.3c)
Regions and people with considerable development constraints
have high vulnerability to climatic hazards. Adaptation
outcomes for the most vulnerable within and across countries
and regions are enhanced through approaches focusing on
equity, inclusivity, and rights-based approaches, including 3.3 to
3.6 billion people living in contexts that are highly vulnerable
to climate change (high confidence). |
{WGII SPM B.5.1, WGII SPM C.2.9,
WGII SPM D.2.1, WGII TS Box TS.4; WGIII SPM D.3, WGIII SPM D.3.3,
WGIII SPM WGIII SPM E.3, SR1.5 SPM D.4.5} (Figure 4.3c)
Regions and people with considerable development constraints
have high vulnerability to climatic hazards. Adaptation
outcomes for the most vulnerable within and across countries
and regions are enhanced through approaches focusing on
equity, inclusivity, and rights-based approaches, including 3.3 to
3.6 billion people living in contexts that are highly vulnerable
to climate change (high confidence). Vulnerability is higher in
locations with poverty, governance challenges and limited access
to basic services and resources, violent conflict and high levels of
climate-sensitive livelihoods (e.g., smallholder farmers, pastoralists,
fishing communities) (high confidence). Several risks can be moderated
with adaptation (high confidence). The largest adaptation gaps
exist among lower income population groups (high confidence) and
adaptation progress is unevenly distributed with observed adaptation
gaps (high confidence). Present development challenges causing high
vulnerability are influenced by historical and ongoing patterns of
inequity such as colonialism, especially for many Indigenous Peoples
and local communities (high confidence). Vulnerability is exacerbated
by inequity and marginalisation linked to gender, ethnicity, low income
or combinations thereof, especially for many Indigenous Peoples and
local communities (high confidence). |
Several risks can be moderated
with adaptation (high confidence). The largest adaptation gaps
exist among lower income population groups (high confidence) and
adaptation progress is unevenly distributed with observed adaptation
gaps (high confidence). Present development challenges causing high
vulnerability are influenced by historical and ongoing patterns of
inequity such as colonialism, especially for many Indigenous Peoples
and local communities (high confidence). Vulnerability is exacerbated
by inequity and marginalisation linked to gender, ethnicity, low income
or combinations thereof, especially for many Indigenous Peoples and
local communities (high confidence). {WGII SPM B.2, WGII SPM B.2.4,
WGII SPM B.3.2, WGII SPM B.3.3, WGII SPM C.1, WGII SPM C.1.2,
WGII SPM C.2.9}
Meaningful participation and inclusive planning, informed by
cultural values, Indigenous Knowledge, local knowledge, and
scientific knowledge can help address adaptation gaps and
avoid maladaptation (high confidence). Such actions with flexible
pathways may encourage low-regret and timely actions (very high
confidence). Integrating climate adaptation into social protection
programmes, including cash transfers and public works programmes,
would increase resilience to climate change, especially when supported
by basic services and infrastructure (high confidence). {WGII SPM C.2.3,
WGII SPM C.4.3, WGII SPM C.4.4, WGII SPM C.2.9, WGII WPM D.3}
Equity, inclusion, just transitions, broad and meaningful
participation of all relevant actors in decision making at
all scales enable deeper societal ambitions for accelerated
mitigation, and climate action more broadly, and build social
trust, support transformative changes and an equitable sharing
of benefits and burdens (high confidence). |
Such actions with flexible
pathways may encourage low-regret and timely actions (very high
confidence). Integrating climate adaptation into social protection
programmes, including cash transfers and public works programmes,
would increase resilience to climate change, especially when supported
by basic services and infrastructure (high confidence). {WGII SPM C.2.3,
WGII SPM C.4.3, WGII SPM C.4.4, WGII SPM C.2.9, WGII WPM D.3}
Equity, inclusion, just transitions, broad and meaningful
participation of all relevant actors in decision making at
all scales enable deeper societal ambitions for accelerated
mitigation, and climate action more broadly, and build social
trust, support transformative changes and an equitable sharing
of benefits and burdens (high confidence). Equity remains a
central element in the UN climate regime, notwithstanding shifts
in differentiation between states over time and challenges in
assessing fair shares. Ambitious mitigation pathways imply large and
sometimes disruptive changes in economic structure, with significant
distributional consequences, within and between countries, including
shifting of income and employment during the transition from high to
low emissions activities (high confidence). While some jobs may be lost,
low-emissions development can also open up opportunities to enhance
skills and create jobs (high confidence). Broadening equitable access
to finance, technologies and governance that facilitate mitigation, and
consideration of climate justice can help equitable sharing of benefits
4.4 Equity and Inclusion in Climate Change Action |
102
Section 4
Section 1
Section 4
and burdens, especially for vulnerable countries and communities.
{WGIII SPM D.3, WGIII SPM D.3.2, WGIII SPM D.3.3, WGIII SPM D.3.4,
WGIII TS Box TS.4}
Development priorities among countries also reflect different
starting points and contexts, and enabling conditions for
shifting development pathways towards increased sustainability
will therefore differ, giving rise to different needs (high
confidence). Implementing just transition principles through collective
and participatory decision-making processes is an effective way of
integrating equity principles into policies at all scales depending
on national circumstances, while in several countries just transition
commissions, task forces and national policies have been established
(medium confidence). {WGIII SPM D.3.1, WGIII SPM D.3.3}
Many economic and regulatory instruments have been
effective in reducing emissions and practical experience has
informed instrument design to improve them while addressing
distributional goals and social acceptance (high confidence). The
design of behavioural interventions, including the way that choices are
presented to consumers work synergistically with price signals, making
the combination more effective (medium confidence). Individuals with
high socio-economic status contribute disproportionately to emissions,
and have the highest potential for emissions reductions, e.g., as
citizens, investors, consumers, role models, and professionals (high
confidence). There are options on design of instruments such as taxes,
subsidies, prices, and consumption-based approaches, complemented
by regulatory instruments to reduce high-emissions consumption while
improving equity and societal well-being (high confidence). Behaviour
and lifestyle changes to help end-users adopt low-GHG-intensive
options can be supported by policies, infrastructure and technology
with multiple co-benefits for societal well-being (high confidence).
Broadening equitable access to domestic and international finance,
technologies and capacity can also act as a catalyst for accelerating
mitigation and shifting development pathways in low-income contexts
(high confidence). |
Individuals with
high socio-economic status contribute disproportionately to emissions,
and have the highest potential for emissions reductions, e.g., as
citizens, investors, consumers, role models, and professionals (high
confidence). There are options on design of instruments such as taxes,
subsidies, prices, and consumption-based approaches, complemented
by regulatory instruments to reduce high-emissions consumption while
improving equity and societal well-being (high confidence). Behaviour
and lifestyle changes to help end-users adopt low-GHG-intensive
options can be supported by policies, infrastructure and technology
with multiple co-benefits for societal well-being (high confidence).
Broadening equitable access to domestic and international finance,
technologies and capacity can also act as a catalyst for accelerating
mitigation and shifting development pathways in low-income contexts
(high confidence). Eradicating extreme poverty, energy poverty, and
providing decent living standards to all in these regions in the context of
achieving sustainable development objectives, in the near term, can be
achieved without significant global emissions growth (high confidence).
Technology development, transfer, capacity building and financing can
support developing countries/ regions leapfrogging or transitioning to
low-emissions transport systems thereby providing multiple co-benefits
(high confidence). Climate resilient development is advanced when
actors work in equitable, just and enabling ways to reconcile divergent
interests, values and worldviews, toward equitable and just outcomes
(high confidence). |
Broadening equitable access to domestic and international finance,
technologies and capacity can also act as a catalyst for accelerating
mitigation and shifting development pathways in low-income contexts
(high confidence). Eradicating extreme poverty, energy poverty, and
providing decent living standards to all in these regions in the context of
achieving sustainable development objectives, in the near term, can be
achieved without significant global emissions growth (high confidence).
Technology development, transfer, capacity building and financing can
support developing countries/ regions leapfrogging or transitioning to
low-emissions transport systems thereby providing multiple co-benefits
(high confidence). Climate resilient development is advanced when
actors work in equitable, just and enabling ways to reconcile divergent
interests, values and worldviews, toward equitable and just outcomes
(high confidence). {WGII D.2.1, WGIII SPM B.3.3, WGIII SPM.C.8.5, WGIII
SPM C.10.2, WGIII SPM C.10.4, WGIII SPM D.3.4, WGIII SPM E.4.2,
WGIII TS.5.1, WGIII 5.4, WGIII 5.8, WGIII 15.2}
Rapid and far-reaching transitions across all sectors and systems
are necessary to achieve deep emissions reductions and secure
a liveable and sustainable future for all (high confidence). System
transitions151 consistent with pathways that limit warming to 1.5°C
(>50%) with no or limited overshoot are more rapid and pronounced
in the near-term than in those that limit warming to 2°C (>67%)
(high confidence). Such a systemic change is unprecedented in terms
of scale, but not necessarily in terms of speed (medium confidence).
The system transitions make possible the transformative adaptation
required for high levels of human health and well-being, economic and
social resilience, ecosystem health, and planetary health. |
System
transitions151 consistent with pathways that limit warming to 1.5°C
(>50%) with no or limited overshoot are more rapid and pronounced
in the near-term than in those that limit warming to 2°C (>67%)
(high confidence). Such a systemic change is unprecedented in terms
of scale, but not necessarily in terms of speed (medium confidence).
The system transitions make possible the transformative adaptation
required for high levels of human health and well-being, economic and
social resilience, ecosystem health, and planetary health. {WGII SPM
A, WGII Figure SPM.1; WGIII SPM C.3; SR1.5 SPM C.2, SR1.5 SPM
C.2.1, SR1.5 SPM C.2, SR1.5 SPM C.5}
Feasible, effective and low-cost options for mitigation and
adaptation are already available (high confidence) (Figure 4.4).
Mitigation options costing USD 100 tCO2-eq–1 or less could reduce
151 System transitions involve a wide portfolio of mitigation and adaptation options that enable deep emissions reductions and transformative adaptation in all sectors. This report
has a particular focus on the following system transitions: energy; industry; cities, settlements and infrastructure; land, ocean, food and water; health and nutrition; and society,
livelihood and economies. {WGII SPM A, WGII Figure SPM.1, WGII Figure SPM.4; SR1.5 SPM C.2}
152 See Annex I: Glossary.
global GHG emissions by at least half the 2019 level by 2030 (options
costing less than USD 20 tCO2-eq–1 are estimated to make up more
than half of this potential) (high confidence) (Figure 4.4). The
availability, feasibility152 and potential of mitigation or effectiveness
of adaptation options in the near term differ across systems and
regions (very high confidence). |
This report
has a particular focus on the following system transitions: energy; industry; cities, settlements and infrastructure; land, ocean, food and water; health and nutrition; and society,
livelihood and economies. {WGII SPM A, WGII Figure SPM.1, WGII Figure SPM.4; SR1.5 SPM C.2}
152 See Annex I: Glossary.
global GHG emissions by at least half the 2019 level by 2030 (options
costing less than USD 20 tCO2-eq–1 are estimated to make up more
than half of this potential) (high confidence) (Figure 4.4). The
availability, feasibility152 and potential of mitigation or effectiveness
of adaptation options in the near term differ across systems and
regions (very high confidence). {WGII SPM C.2; WGIII SPM C.12,
WGIII SPM E.1.1; SR1.5 SPM B.6}
Demand-side measures and new ways of end-use service
provision can reduce global GHG emissions in end-use sectors by
40 to 70% by 2050 compared to baseline scenarios, while some
regions and socioeconomic groups require additional energy
and resources. Demand-side mitigation encompasses changes in
infrastructure use, end-use technology adoption, and socio-cultural and
behavioural change. (high confidence) (Figure 4.4). {WGIII SPM C.10}
4.5 Near-Term Mitigation and Adaptation Actions
Rapid and far-reaching transitions across all sectors and systems are necessary to achieve deep and sustained
emissions reductions and secure a liveable and sustainable future for all. These system transitions involve a
significant upscaling of a wide portfolio of mitigation and adaptation options. Feasible, effective and low-cost
options for mitigation and adaptation are already available, with differences across systems and regions. (high
confidence) |
103
Near-Term Responses in a Changing Climate
Section 4
There are multiple opportunities for scaling up climate action
Costs are lower than the reference
0–20 (USD per tCO2-eq)
20–50 (USD per tCO2-eq)
50–100 (USD per tCO2-eq)
100–200 (USD per tCO2-eq)
Cost not allocated due to high
variability or lack of data
Net lifetime cost of options:
Feasibility level and synergies
with mitigation
Insufficient evidence
Confidence level in potential feasibility
and in synergies with mitigation
Medium
High
Low
a) Feasibility of climate responses and adaptation, and potential of mitigation options in the near term
High
Medium
Low
Synergies
with
mitigation
not
assessed
0
1
2
3
4
5
Potential contribution to
net emission reduction, 2030
Carbon capture with
utilisation (CCU) and CCS
Material efficiency
Enhanced recycling
Construction materials substitution
Energy efficiency
Wind
Solar
Reduce methane and N2O in agriculture
Reduce food loss and food waste
Geothermal and hydropower
Carbon sequestration in agriculture
Reduce conversion of natural ecosystems
Nuclear
Reduce methane from coal, oil and gas
Bioelectricity (includes BECCS)
Fossil Carbon Capture and Storage (CCS)
Ecosystem restoration,
afforestation, reforestation
Fuel switching
Reduce emission of fluorinated gas
Reduce methane from
waste/wastewater
Improved sustainable forest management
Climate responses and
adaptation options
Mitigation options
GtCO2-eq/yr
Enhanced health services
(e.g. |
WASH, nutrition and diets)
Green infrastructure and
ecosystem services
Sustainable land use and urban planning
Sustainable urban water management
Climate services, including
Early Warning Systems
Livelihood diversification
Disaster risk management
Social safety nets
Risk spreading and sharing
Planned relocation and resettlement
Human migration
Agroforestry
Sustainable aquaculture and fisheries
Efficient livestock systems
Biodiversity management and
ecosystem connectivity
Integrated coastal zone management
Water use efficiency and water
resource management
Improved cropland management
Coastal defence and hardening
Forest-based adaptation
Resilient power systems
Energy reliability (e.g.
diversification, access, stability)
Improve water use efficiency
Potential
feasibility
up to 1.5°C
ENERGY SUPPLY
LAND, WATER, FOOD
HEALTH
SETTLEMENTS AND
INFRASTRUCTURE
SOCIETY, LIVELIHOOD
AND ECONOMY
INDUSTRY AND WASTE
20
10
0
20
10
0
Electricity
Land transport
Buildings
Industry
Food
67%
66%
29%
44%
73% reduction (before
additional electrification)
Additional electrification (+60%)
GtCO2-eq/yr
GtCO2/yr
Key
Total emissions (2050)
Percentage of possible reduction
Demand-side mitigation potential
Potential range
%
Efficient lighting, appliances
and equipment
Efficient shipping and aviation
Avoid demand for energy services
Efficient buildings
Electric vehicles
Public transport and bicycling
Biofuels for transport
Onsite renewables
Fuel efficient vehicles
Shift to sustainable healthy diets
options costing 100 USD tCO2-eq-1 or
less could reduce global emissions by
at least half of the 2019 level by 2030
b) Potential of demand-side
mitigation options by 2050
the range of GHG emissions
reduction potential is 40-70%
in these end-use sectors |
104
Section 4
Section 1
Section 4
Figure 4.4: Multiple Opportunities for scaling up climate action. Panel (a) presents selected mitigation and adaptation options across different systems. The left hand side
of panel (a) shows climate responses and adaptation options assessed for their multidimensional feasibility at global scale, in the near term and up to 1.5°C global warming. As
literature above 1.5°C is limited, feasibility at higher levels of warming may change, which is currently not possible to assess robustly. The term response is used here in addition to
adaptation because some responses, such as migration, relocation and resettlement may or may not be considered to be adaptation. Migration, when voluntary, safe and orderly,
allows reduction of risks to climatic and non-climatic stressors. Forest based adaptation includes sustainable forest management, forest conservation and restoration, reforestation
and afforestation. WASH refers to water, sanitation and hygiene. Six feasibility dimensions (economic, technological, institutional, social, environmental and geophysical) were used
to calculate the potential feasibility of climate responses and adaptation options, along with their synergies with mitigation. For potential feasibility and feasibility dimensions, the
figure shows high, medium, or low feasibility. Synergies with mitigation are identified as high, medium, and low. The right-hand side of panel (a) provides an overview of selected
mitigation options and their estimated costs and potentials in 2030. Relative potentials and costs will vary by place, context and time and in the longer term compared to 2030. Costs
are net lifetime discounted monetary costs of avoided greenhouse gas emissions calculated relative to a reference technology. The potential (horizontal axis) is the quantity of net
GHG emission reduction that can be achieved by a given mitigation option relative to a specified emission baseline. Net GHG emission reductions are the sum of reduced emissions
and/or enhanced sinks. The baseline used consists of current policy (around 2019) reference scenarios from the AR6 scenarios database (25–75 percentile values). The mitigation
potentials are assessed independently for each option and are not necessarily additive. |
Synergies with mitigation are identified as high, medium, and low. The right-hand side of panel (a) provides an overview of selected
mitigation options and their estimated costs and potentials in 2030. Relative potentials and costs will vary by place, context and time and in the longer term compared to 2030. Costs
are net lifetime discounted monetary costs of avoided greenhouse gas emissions calculated relative to a reference technology. The potential (horizontal axis) is the quantity of net
GHG emission reduction that can be achieved by a given mitigation option relative to a specified emission baseline. Net GHG emission reductions are the sum of reduced emissions
and/or enhanced sinks. The baseline used consists of current policy (around 2019) reference scenarios from the AR6 scenarios database (25–75 percentile values). The mitigation
potentials are assessed independently for each option and are not necessarily additive. Health system mitigation options are included mostly in settlement and infrastructure
(e.g., efficient healthcare buildings) and cannot be identified separately. Fuel switching in industry refers to switching to electricity, hydrogen, bioenergy and natural gas. The length
of the solid bars represents the mitigation potential of an option. Potentials are broken down into cost categories, indicated by different colours (see legend). Only discounted lifetime
monetary costs are considered. Where a gradual colour transition is shown, the breakdown of the potential into cost categories is not well known or depends heavily on factors such
as geographical location, resource availability, and regional circumstances, and the colours indicate the range of estimates. The uncertainty in the total potential is typically 25–50%.
When interpreting this figure, the following should be taken into account: (1) The mitigation potential is uncertain, as it will depend on the reference technology (and emissions)
being displaced, the rate of new technology adoption, and several other factors; (2) Different options have different feasibilities beyond the cost aspects, which are not reflected in
the figure; and (3) Costs for accommodating the integration of variable renewable energy sources in electricity systems are expected to be modest until 2030, and are not included. |
Only discounted lifetime
monetary costs are considered. Where a gradual colour transition is shown, the breakdown of the potential into cost categories is not well known or depends heavily on factors such
as geographical location, resource availability, and regional circumstances, and the colours indicate the range of estimates. The uncertainty in the total potential is typically 25–50%.
When interpreting this figure, the following should be taken into account: (1) The mitigation potential is uncertain, as it will depend on the reference technology (and emissions)
being displaced, the rate of new technology adoption, and several other factors; (2) Different options have different feasibilities beyond the cost aspects, which are not reflected in
the figure; and (3) Costs for accommodating the integration of variable renewable energy sources in electricity systems are expected to be modest until 2030, and are not included.
Panel (b) displays the indicative potential of demand-side mitigation options for 2050. Potentials are estimated based on approximately 500 bottom-up studies representing all
global regions. The baseline (white bar) is provided by the sectoral mean GHG emissions in 2050 of the two scenarios (IEA-STEPS and IP_ModAct) consistent with policies announced
by national governments until 2020. The green arrow represents the demand-side emissions reductions potentials. The range in potential is shown by a line connecting dots displaying
the highest and the lowest potentials reported in the literature. Food shows demand-side potential of socio-cultural factors and infrastructure use, and changes in land-use patterns
enabled by change in food demand. Demand-side measures and new ways of end-use service provision can reduce global GHG emissions in end-use sectors (buildings, land transport,
food) by 40–70% by 2050 compared to baseline scenarios, while some regions and socioeconomic groups require additional energy and resources. The last row shows how demand-
side mitigation options in other sectors can influence overall electricity demand. The dark grey bar shows the projected increase in electricity demand above the 2050 baseline due
to increasing electrification in the other sectors. |
The green arrow represents the demand-side emissions reductions potentials. The range in potential is shown by a line connecting dots displaying
the highest and the lowest potentials reported in the literature. Food shows demand-side potential of socio-cultural factors and infrastructure use, and changes in land-use patterns
enabled by change in food demand. Demand-side measures and new ways of end-use service provision can reduce global GHG emissions in end-use sectors (buildings, land transport,
food) by 40–70% by 2050 compared to baseline scenarios, while some regions and socioeconomic groups require additional energy and resources. The last row shows how demand-
side mitigation options in other sectors can influence overall electricity demand. The dark grey bar shows the projected increase in electricity demand above the 2050 baseline due
to increasing electrification in the other sectors. Based on a bottom-up assessment, this projected increase in electricity demand can be avoided through demand-side mitigation
options in the domains of infrastructure use and socio-cultural factors that influence electricity usage in industry, land transport, and buildings (green arrow). {WGII Figure SPM.4,
WGII Cross-Chapter Box FEASIB in Chapter 18; WGIII SPM C.10, WGIII 12.2.1, WGIII 12.2.2, WGIII Figure SPM.6, WGIII Figure SPM.7}
4.5.1. Energy Systems
Rapid and deep reductions in GHG emissions require major
energy system transitions (high confidence). Adaptation options
can help reduce climate-related risks to the energy system
(very high confidence). Net zero CO2 energy systems entail: a
substantial reduction in overall fossil fuel use, minimal use of
unabated fossil fuels153, and use of Carbon Capture and Storage in
the remaining fossil fuel systems; electricity systems that emit no
net CO2; widespread electrification; alternative energy carriers in
applications less amenable to electrification; energy conservation
and efficiency; and greater integration across the energy system
(high confidence). |
Energy Systems
Rapid and deep reductions in GHG emissions require major
energy system transitions (high confidence). Adaptation options
can help reduce climate-related risks to the energy system
(very high confidence). Net zero CO2 energy systems entail: a
substantial reduction in overall fossil fuel use, minimal use of
unabated fossil fuels153, and use of Carbon Capture and Storage in
the remaining fossil fuel systems; electricity systems that emit no
net CO2; widespread electrification; alternative energy carriers in
applications less amenable to electrification; energy conservation
and efficiency; and greater integration across the energy system
(high confidence). Large contributions to emissions reductions can
come from options costing less than USD 20 tCO2-eq–1, including
solar and wind energy, energy efficiency improvements, and CH4
(methane) emissions reductions (from coal mining, oil and gas, and
waste) (medium confidence).154 Many of these response options are
technically viable and are supported by the public (high confidence).
Maintaining emission-intensive systems may, in some regions and
sectors, be more expensive than transitioning to low emission
systems (high confidence). {WGII SPM C.2.10; WGIII SPM C.4.1,
WGIII SPM C.4.2, WGIII SPM C.12.1, WGIII SPM E.1.1, WGIII TS.5.1}
Climate change and related extreme events will affect future energy
systems, including hydropower production, bioenergy yields, thermal
power plant efficiencies, and demands for heating and cooling (high
153 In this context, ‘unabated fossil fuels’ refers to fossil fuels produced and used without interventions that substantially reduce the amount of GHG emitted throughout the life
cycle; for example, capturing 90% or more CO2 from power plants, or 50–80% of fugitive methane emissions from energy supply. {WGIII SPM footnote 54}
154 The mitigation potentials and mitigation costs of individual technologies in a specific context or region may differ greatly from the provided estimates (medium confidence). |
{WGIII SPM footnote 54}
154 The mitigation potentials and mitigation costs of individual technologies in a specific context or region may differ greatly from the provided estimates (medium confidence).
{WGIII SPM C.12.1}
confidence). The most feasible energy system adaptation options
support infrastructure resilience, reliable power systems and efficient
water use for existing and new energy generation systems (very
high confidence). Adaptations for hydropower and thermo-electric
power generation are effective in most regions up to 1.5°C to 2°C,
with decreasing effectiveness at higher levels of warming (medium
confidence). Energy generation diversification (e.g., wind, solar, small-
scale hydroelectric) and demand side management (e.g., storage and
energy efficiency improvements) can increase energy reliability and
reduce vulnerabilities to climate change, especially in rural populations
(high confidence). Climate responsive energy markets, updated design
standards on energy assets according to current and projected climate
change, smart-grid technologies, robust transmission systems and
improved capacity to respond to supply deficits have high feasibility
in the medium- to long-term, with mitigation co-benefits (very high
confidence). {WGII SPM B.5.3, WGII SPM C.2.10; WGIII TS.5.1}
4.5.2. Industry
There are several options to reduce industrial emissions
that differ by type of industry; many industries are disrupted
by climate change, especially from extreme events (high
confidence). Reducing industry emissions will entail coordinated
action throughout value chains to promote all mitigation options,
including demand management, energy and materials efficiency,
circular material flows, as well as abatement technologies and |
105
Near-Term Responses in a Changing Climate
Section 4
transformational changes in production processes (high confidence).
Light industry and manufacturing can be largely decarbonized through
available abatement technologies (e.g., material efficiency, circularity),
electrification (e.g., electrothermal heating, heat pumps), and switching
to low- and zero-GHG emitting fuels (e.g., hydrogen, ammonia, and
bio-based and other synthetic fuels) (high confidence), while deep
reduction of cement process emissions will rely on cementitious
material substitution and the availability of Carbon Capture and Storage
(CCS) until new chemistries are mastered (high confidence). Reducing
emissions from the production and use of chemicals would need to rely
on a life cycle approach, including increased plastics recycling, fuel and
feedstock switching, and carbon sourced through biogenic sources, and,
depending on availability, Carbon Capture and Utilisation (CCU), direct
air CO2 capture, as well as CCS (high confidence). Action to reduce
industry sector emissions may change the location of GHG-intensive
industries and the organisation of value chains, with distributional
effects on employment and economic structure (medium confidence).
{WGII TS.B.9.1, WGII 16.5.2; WGIII SPM C.5, WGIII SPM C.5.2,
WGIII SPM C.5.3, WGIII TS.5.5}
Many industrial and service sectors are negatively affected by climate
change through supply and operational disruptions, especially from
extreme events (high confidence), and will require adaptation efforts.
Water intensive industries (e.g., mining) can undertake measures to
reduce water stress, such as water recycling and reuse, using brackish
or saline sources, working to improve water use efficiency. However,
residual risks will remain, especially at higher levels of warming
(medium confidence). |
{WGII TS.B.9.1, WGII 16.5.2; WGIII SPM C.5, WGIII SPM C.5.2,
WGIII SPM C.5.3, WGIII TS.5.5}
Many industrial and service sectors are negatively affected by climate
change through supply and operational disruptions, especially from
extreme events (high confidence), and will require adaptation efforts.
Water intensive industries (e.g., mining) can undertake measures to
reduce water stress, such as water recycling and reuse, using brackish
or saline sources, working to improve water use efficiency. However,
residual risks will remain, especially at higher levels of warming
(medium confidence). {WGII TS.B.9.1, WGII 16.5.2, WGII 4.6.3} (Section 3.2)
4.5.3. Cities, Settlements and Infrastructure
Urban systems are critical for achieving deep emissions
reductions and advancing climate resilient development,
particularly when this involves integrated planning that
incorporates physical, natural and social infrastructure (high
confidence). Deep emissions reductions and integrated adaptation
actions are advanced by: integrated, inclusive land use planning
and decision-making; compact urban form by co-locating jobs and
housing; reducing or changing urban energy and material consumption;
electrification in combination with low emissions sources; improved
water and waste management infrastructure; and enhancing carbon
uptake and storage in the urban environment (e.g. bio-based building
materials, permeable surfaces and urban green and blue infrastructure).
Cities can achieve net zero emissions if emissions are reduced within
and outside of their administrative boundaries through supply chains,
creating beneficial cascading effects across other sectors. |
Cities, Settlements and Infrastructure
Urban systems are critical for achieving deep emissions
reductions and advancing climate resilient development,
particularly when this involves integrated planning that
incorporates physical, natural and social infrastructure (high
confidence). Deep emissions reductions and integrated adaptation
actions are advanced by: integrated, inclusive land use planning
and decision-making; compact urban form by co-locating jobs and
housing; reducing or changing urban energy and material consumption;
electrification in combination with low emissions sources; improved
water and waste management infrastructure; and enhancing carbon
uptake and storage in the urban environment (e.g. bio-based building
materials, permeable surfaces and urban green and blue infrastructure).
Cities can achieve net zero emissions if emissions are reduced within
and outside of their administrative boundaries through supply chains,
creating beneficial cascading effects across other sectors. (high confidence)
{WGII SPM C.5.6, WGII SPM D.1.3, WGII SPM D.3; WGIII SPM C.6, WGIII
SPM C.6.2, WGIII TS 5.4, SR1.5 SPM C.2.4}
Considering climate change impacts and risks (e.g., through climate
services) in the design and planning of urban and rural settlements
and infrastructure is critical for resilience and enhancing human
well-being. Effective mitigation can be advanced at each of the design,
construction, retrofit, use and disposal stages for buildings. Mitigation
interventions for buildings include: at the construction phase, low-
155 A set of measures and daily practices that avoid demand for energy, materials, land and water while delivering human well-being for all within planetary boundaries.
{WGIII Annex I}
emission construction materials, highly efficient building envelope
and the integration of renewable energy solutions; at the use phase,
highly efficient appliances/equipment, the optimisation of the use
of buildings and their supply with low-emission energy sources;
and at the disposal phase, recycling and re-using construction
materials. Sufficiency155 measures can limit the demand for energy
and materials over the lifecycle of buildings and appliances. |
Effective mitigation can be advanced at each of the design,
construction, retrofit, use and disposal stages for buildings. Mitigation
interventions for buildings include: at the construction phase, low-
155 A set of measures and daily practices that avoid demand for energy, materials, land and water while delivering human well-being for all within planetary boundaries.
{WGIII Annex I}
emission construction materials, highly efficient building envelope
and the integration of renewable energy solutions; at the use phase,
highly efficient appliances/equipment, the optimisation of the use
of buildings and their supply with low-emission energy sources;
and at the disposal phase, recycling and re-using construction
materials. Sufficiency155 measures can limit the demand for energy
and materials over the lifecycle of buildings and appliances. (high
confidence) {WGII SPM C.2.5; WGIII SPM C.7.2}
Transport-related GHG emissions can be reduced by demand-side
options and low-GHG emissions technologies. Changes in urban form,
reallocation of street space for cycling and walking, digitalisation
(e.g., teleworking) and programs that encourage changes in consumer
behaviour (e.g. transport, pricing) can reduce demand for transport
services and support the shift to more energy efficient transport
modes (high confidence). Electric vehicles powered by low-emissions
electricity offer the largest decarbonisation potential for land-based
transport, on a life cycle basis (high confidence). Costs of electrified
vehicles are decreasing and their adoption is accelerating, but they
require continued investments in supporting infrastructure to increase
scale of deployment (high confidence). The environmental footprint of
battery production and growing concerns about critical minerals can
be addressed by material and supply diversification strategies, energy
and material efficiency improvements, and circular material flows
(medium confidence). Advances in battery technologies could facilitate
the electrification of heavy-duty trucks and compliment conventional
electric rail systems (medium confidence). |
Electric vehicles powered by low-emissions
electricity offer the largest decarbonisation potential for land-based
transport, on a life cycle basis (high confidence). Costs of electrified
vehicles are decreasing and their adoption is accelerating, but they
require continued investments in supporting infrastructure to increase
scale of deployment (high confidence). The environmental footprint of
battery production and growing concerns about critical minerals can
be addressed by material and supply diversification strategies, energy
and material efficiency improvements, and circular material flows
(medium confidence). Advances in battery technologies could facilitate
the electrification of heavy-duty trucks and compliment conventional
electric rail systems (medium confidence). Sustainable biofuels can offer
additional mitigation benefits in land-based transport in the short and
medium term (medium confidence). Sustainable biofuels, low-emissions
hydrogen, and derivatives (including synthetic fuels) can support
mitigation of CO2 emissions from shipping, aviation, and heavy-duty
land transport but require production process improvements and cost
reductions (medium confidence). Key infrastructure systems including
sanitation, water, health, transport, communications and energy will
be increasingly vulnerable if design standards do not account for
changing climate conditions (high confidence). {WGII SPM B.2.5;
WGIII SPM C.6.2, WGIII SPM C.8, WGIII SPM C.8.1, WGIII SPM C.8.2,
WGIII SPM C.10.2, WGIII SPM C.10.3, WGIII SPM C.10.4}
Green/natural and blue infrastructure such as urban forestry, green
roofs, ponds and lakes, and river restoration can mitigate climate change
through carbon uptake and storage, avoided emissions, and reduced
energy use while reducing risk from extreme events such as heatwaves,
heavy precipitation and droughts, and advancing co-benefits for health,
well-being and livelihoods (medium confidence). |
{WGII SPM B.2.5;
WGIII SPM C.6.2, WGIII SPM C.8, WGIII SPM C.8.1, WGIII SPM C.8.2,
WGIII SPM C.10.2, WGIII SPM C.10.3, WGIII SPM C.10.4}
Green/natural and blue infrastructure such as urban forestry, green
roofs, ponds and lakes, and river restoration can mitigate climate change
through carbon uptake and storage, avoided emissions, and reduced
energy use while reducing risk from extreme events such as heatwaves,
heavy precipitation and droughts, and advancing co-benefits for health,
well-being and livelihoods (medium confidence). Urban greening can
provide local cooling (very high confidence). Combining green/natural
and grey/physical infrastructure adaptation responses has potential
to reduce adaptation costs and contribute to flood control, sanitation,
water resources management, landslide prevention and coastal
protection (medium confidence). Globally, more financing is directed
at grey/physical infrastructure than green/natural infrastructure
and social infrastructure (medium confidence), and there is limited
evidence of investment in informal settlements (medium to high
confidence). The greatest gains in well-being in urban areas can be
achieved by prioritising finance to reduce climate risk for low-income |
106
Section 4
Section 1
Section 4
and marginalised communities including people living in informal
settlements (high confidence). {WGII SPM C.2.5, WGII SPM C.2.6, WGII
SPM C.2.7, WGII SPM D.3.2, WGII TS.E.1.4, WGII Cross-Chapter Box FEAS;
WGIII SPM C.6, WGIII SPM C.6.2, WGIII SPM D.1.3, WGIII SPM D.2.1}
Responses to ongoing sea level rise and land subsidence in low-lying
coastal cities and settlements and small islands include protection,
accommodation, advance and planned relocation. These responses
are more effective if combined and/or sequenced, planned well ahead,
aligned with sociocultural values and development priorities, and
underpinned by inclusive community engagement processes. (high
confidence) {WGII SPM C.2.8}
4.5.4. Land, Ocean, Food, and Water
There is substantial mitigation and adaptation potential from
options in agriculture, forestry and other land use, and in the
oceans, that could be upscaled in the near term across most
regions (high confidence) (Figure 4.5). Conservation, improved
management, and restoration of forests and other ecosystems offer
the largest share of economic mitigation potential, with reduced
deforestation in tropical regions having the highest total mitigation
potential. Ecosystem restoration, reforestation, and afforestation can
lead to trade-offs due to competing demands on land. Minimizing
trade-offs requires integrated approaches to meet multiple objectives
including food security. Demand-side measures (shifting to sustainable
healthy diets and reducing food loss/waste) and sustainable agricultural
intensification can reduce ecosystem conversion and CH4 and N2O emissions,
and free up land for reforestation and ecosystem restoration.
Sustainably sourced agriculture and forest products, including
long-lived wood products, can be used instead of more GHG-intensive
products in other sectors. |
Conservation, improved
management, and restoration of forests and other ecosystems offer
the largest share of economic mitigation potential, with reduced
deforestation in tropical regions having the highest total mitigation
potential. Ecosystem restoration, reforestation, and afforestation can
lead to trade-offs due to competing demands on land. Minimizing
trade-offs requires integrated approaches to meet multiple objectives
including food security. Demand-side measures (shifting to sustainable
healthy diets and reducing food loss/waste) and sustainable agricultural
intensification can reduce ecosystem conversion and CH4 and N2O emissions,
and free up land for reforestation and ecosystem restoration.
Sustainably sourced agriculture and forest products, including
long-lived wood products, can be used instead of more GHG-intensive
products in other sectors. Effective adaptation options include cultivar
improvements, agroforestry, community-based adaptation, farm and
landscape diversification, and urban agriculture. These AFOLU response
options require integration of biophysical, socioeconomic and other
enabling factors. The effectiveness of ecosystem-based adaptation
and most water-related adaptation options declines with increasing
warming (see 3.2). (high confidence) {WGII SPM C.2.1, WGII SPM C.2.2,
WGII SPM C.2.5; WGIII SPM C.9.1; SRCCL SPM B.1.1, SRCCL SPM B.5.4,
SRCCL SPM D.1; SROCC SPM C}
Some options, such as conservation of high-carbon ecosystems
(e.g., peatlands, wetlands, rangelands, mangroves and forests), have
immediate impacts while others, such as restoration of high-carbon
ecosystems, reclamation of degraded soils or afforestation, take decades
to deliver measurable results (high confidence). Many sustainable land
management technologies and practices are financially profitable in three
to ten years (medium confidence). |
(high confidence) {WGII SPM C.2.1, WGII SPM C.2.2,
WGII SPM C.2.5; WGIII SPM C.9.1; SRCCL SPM B.1.1, SRCCL SPM B.5.4,
SRCCL SPM D.1; SROCC SPM C}
Some options, such as conservation of high-carbon ecosystems
(e.g., peatlands, wetlands, rangelands, mangroves and forests), have
immediate impacts while others, such as restoration of high-carbon
ecosystems, reclamation of degraded soils or afforestation, take decades
to deliver measurable results (high confidence). Many sustainable land
management technologies and practices are financially profitable in three
to ten years (medium confidence). {SRCCL SPM B.1.2, SRCCL SPM D.2.2}
Maintaining the resilience of biodiversity and ecosystem
services at a global scale depends on effective and equitable
conservation of approximately 30–50% of Earth’s land,
freshwater and ocean areas, including currently near-natural
ecosystems (high confidence). The services and options provided by
terrestrial, freshwater, coastal and ocean ecosystems can be supported
156 Balanced diets refer to diets that feature plant-based foods, such as those based on coarse grains, legumes, fruits and vegetables, nuts and seeds, and animal-sourced food
produced in resilient, sustainable and low-GHG emission systems, as described in SRCCL.
by protection, restoration, precautionary ecosystem-based management
of renewable resource use, and the reduction of pollution and other
stressors (high confidence). {WGII SPM C.2.4, WGII SPM D.4;
SROCC SPM C.2}
Large-scale land conversion for bioenergy, biochar, or afforestation
can increase risks to biodiversity, water and food security. In contrast,
restoring natural forests and drained peatlands, and improving
sustainability of managed forests enhances the resilience of carbon
stocks and sinks and reduces ecosystem vulnerability to climate change. |
by protection, restoration, precautionary ecosystem-based management
of renewable resource use, and the reduction of pollution and other
stressors (high confidence). {WGII SPM C.2.4, WGII SPM D.4;
SROCC SPM C.2}
Large-scale land conversion for bioenergy, biochar, or afforestation
can increase risks to biodiversity, water and food security. In contrast,
restoring natural forests and drained peatlands, and improving
sustainability of managed forests enhances the resilience of carbon
stocks and sinks and reduces ecosystem vulnerability to climate change.
Cooperation, and inclusive decision making, with local communities
and Indigenous Peoples, as well as recognition of inherent rights of
Indigenous Peoples, is integral to successful adaptation across
forests and other ecosystems. (high confidence) {WGII SPM B.5.4,
WGII SPM C.2.3, WGII SPM C.2.4; WGIII SPM D.2.3; SRCCL B.7.3,
SRCCL SPM C.4.3, SRCCL TS.7}
Natural rivers, wetlands and upstream forests reduce flood risk in most
circumstances (high confidence). Enhancing natural water retention
such as by restoring wetlands and rivers, land use planning such as no
build zones or upstream forest management, can further reduce flood risk
(medium confidence). For inland flooding, combinations of non-structural
measures like early warning systems and structural measures like levees
have reduced loss of lives (medium confidence), but hard defences
against flooding or sea level rise can also be maladaptive
(high confidence). {WGII SPM C.2.1, WGII SPM C.4.1, WGII SPM C.4.2,
WGII SPM C.2.5}
Protection and restoration of coastal ‘blue carbon’ ecosystems
(e.g., mangroves, tidal marshes and seagrass meadows) could
reduce emissions and/or increase carbon uptake and storage (medium
confidence). |
Enhancing natural water retention
such as by restoring wetlands and rivers, land use planning such as no
build zones or upstream forest management, can further reduce flood risk
(medium confidence). For inland flooding, combinations of non-structural
measures like early warning systems and structural measures like levees
have reduced loss of lives (medium confidence), but hard defences
against flooding or sea level rise can also be maladaptive
(high confidence). {WGII SPM C.2.1, WGII SPM C.4.1, WGII SPM C.4.2,
WGII SPM C.2.5}
Protection and restoration of coastal ‘blue carbon’ ecosystems
(e.g., mangroves, tidal marshes and seagrass meadows) could
reduce emissions and/or increase carbon uptake and storage (medium
confidence). Coastal wetlands protect against coastal erosion
and flooding (very high confidence). Strengthening precautionary
approaches, such as rebuilding overexploited or depleted fisheries, and
responsiveness of existing fisheries management strategies reduces
negative climate change impacts on fisheries, with benefits for regional
economies and livelihoods (medium confidence). Ecosystem-based
management in fisheries and aquaculture supports food security,
biodiversity, human health and well-being (high confidence).
{WGII SPM C.2.2, WGII SPM C.2; SROCC SPM C2.3, SROCC SPM C.2.4}
4.5.5. Health and Nutrition
Human health will benefit from integrated mitigation and
adaptation options that mainstream health into food,
infrastructure, social protection, and water policies (very high
confidence). Balanced and sustainable healthy diets156 and reduced
food loss and waste present important opportunities for adaptation
and mitigation while generating significant co-benefits in terms
of biodiversity and human health (high confidence). |
Ecosystem-based
management in fisheries and aquaculture supports food security,
biodiversity, human health and well-being (high confidence).
{WGII SPM C.2.2, WGII SPM C.2; SROCC SPM C2.3, SROCC SPM C.2.4}
4.5.5. Health and Nutrition
Human health will benefit from integrated mitigation and
adaptation options that mainstream health into food,
infrastructure, social protection, and water policies (very high
confidence). Balanced and sustainable healthy diets156 and reduced
food loss and waste present important opportunities for adaptation
and mitigation while generating significant co-benefits in terms
of biodiversity and human health (high confidence). Public health
policies to improve nutrition, such as increasing the diversity of food
sources in public procurement, health insurance, financial incentives,
and awareness-raising campaigns, can potentially influence food
demand, reduce food waste, reduce healthcare costs, contribute to
lower GHG emissions and enhance adaptive capacity (high confidence). |
107
Near-Term Responses in a Changing Climate
Section 4
Improved access to clean energy sources and technologies, and shifts
to active mobility (e.g., walking and cycling) and public transport can
deliver socioeconomic, air quality and health benefits, especially
for women and children (high confidence). {WGII SPM C.2.2, WGII
SPM C.2.11, WGII Cross-Chapter Box HEALTH; WGIII SPM C.2.2,
WGIII SPM C.4.2, WGIII SPM C.9.1, WGIII SPM C.10.4, WGIII SPM
D.1.3, WGIII Figure SPM.6, WGIII Figure SPM.8; SRCCL SPM B.6.2,
SRCCL SPM B.6.3, SRCCL B.4.6, SRCCL SPM C.2.4}
Effective adaptation options exist to help protect human health
and well-being (high confidence). Health Action Plans that include
early warning and response systems are effective for extreme heat (high
confidence). Effective options for water-borne and food-borne diseases
include improving access to potable water, reducing exposure of water and
sanitation systems to flooding and extreme weather events, and improved
early warning systems (very high confidence). For vector-borne diseases,
effective adaptation options include surveillance, early warning
systems, and vaccine development (very high confidence). Effective
adaptation options for reducing mental health risks under climate
change include improving surveillance and access to mental health
care, and monitoring of psychosocial impacts from extreme weather
events (high confidence). A key pathway to climate resilience in the
health sector is universal access to healthcare (high confidence).
{WGII SPM C.2.11, WGII 7.4.6}
4.5.6 Society, Livelihoods, and Economies
Enhancing knowledge on risks and available adaptation options
promotes societal responses, and behaviour and lifestyle changes
supported by policies, infrastructure and technology can help
reduce global GHG emissions (high confidence). |
For vector-borne diseases,
effective adaptation options include surveillance, early warning
systems, and vaccine development (very high confidence). Effective
adaptation options for reducing mental health risks under climate
change include improving surveillance and access to mental health
care, and monitoring of psychosocial impacts from extreme weather
events (high confidence). A key pathway to climate resilience in the
health sector is universal access to healthcare (high confidence).
{WGII SPM C.2.11, WGII 7.4.6}
4.5.6 Society, Livelihoods, and Economies
Enhancing knowledge on risks and available adaptation options
promotes societal responses, and behaviour and lifestyle changes
supported by policies, infrastructure and technology can help
reduce global GHG emissions (high confidence). Climate literacy
and information provided through climate services and community
approaches, including those that are informed by Indigenous Knowledge
and local knowledge, can accelerate behavioural changes and planning
(high confidence). Educational and information programmes, using
the arts, participatory modelling and citizen science can facilitate
awareness, heighten risk perception, and influence behaviours (high
confidence). The way choices are presented can enable adoption of low
GHG intensive socio-cultural options, such as shifts to balanced, sustainable
healthy diets, reduced food waste, and active mobility (high confidence).
Judicious labelling, framing, and communication of social norms can
increase the effect of mandates, subsidies, or taxes (medium confidence). |
Climate literacy
and information provided through climate services and community
approaches, including those that are informed by Indigenous Knowledge
and local knowledge, can accelerate behavioural changes and planning
(high confidence). Educational and information programmes, using
the arts, participatory modelling and citizen science can facilitate
awareness, heighten risk perception, and influence behaviours (high
confidence). The way choices are presented can enable adoption of low
GHG intensive socio-cultural options, such as shifts to balanced, sustainable
healthy diets, reduced food waste, and active mobility (high confidence).
Judicious labelling, framing, and communication of social norms can
increase the effect of mandates, subsidies, or taxes (medium confidence).
{WGII SPM C.5.3, WGII TS.D.10.1; WGIII SPM C.10, WGIII SPM C.10.2,
WGIII SPM C.10.3, WGIII SPM E.2.2, WGIII Figure SPM.6, WGIII TS.6.1,
5.4; SR1.5 SPM D.5.6; SROCC SPM C.4}
A range of adaptation options, such as disaster risk management,
early warning systems, climate services and risk spreading and
sharing approaches, have broad applicability across sectors
and provide greater risk reduction benefits when combined
(high confidence). Climate services that are demand-driven and
inclusive of different users and providers can improve agricultural
practices, inform better water use and efficiency, and enable resilient
infrastructure planning (high confidence). Policy mixes that include
weather and health insurance, social protection and adaptive safety
nets, contingent finance and reserve funds, and universal access to
early warning systems combined with effective contingency plans, can
reduce vulnerability and exposure of human systems (high confidence).
Integrating climate adaptation into social protection programs,
including cash transfers and public works programs, is highly feasible
and increases resilience to climate change, especially when supported
by basic services and infrastructure (high confidence). |
Climate services that are demand-driven and
inclusive of different users and providers can improve agricultural
practices, inform better water use and efficiency, and enable resilient
infrastructure planning (high confidence). Policy mixes that include
weather and health insurance, social protection and adaptive safety
nets, contingent finance and reserve funds, and universal access to
early warning systems combined with effective contingency plans, can
reduce vulnerability and exposure of human systems (high confidence).
Integrating climate adaptation into social protection programs,
including cash transfers and public works programs, is highly feasible
and increases resilience to climate change, especially when supported
by basic services and infrastructure (high confidence). Social safety nets
can build adaptive capacities, reduce socioeconomic vulnerability, and
reduce risk linked to hazards (robust evidence, medium agreement).
{WGII SPM C.2.9, WGII SPM C.2.13, WGII Cross-Chapter Box FEASIB in
Chapter 18; SRCCL SPM C.1.4, SRCCL SPM D.1.2}
Reducing future risks of involuntary migration and displacement
due to climate change is possible through cooperative, international
efforts to enhance institutional adaptive capacity and sustainable
development (high confidence). Increasing adaptive capacity minimises
risk associated with involuntary migration and immobility and improves
the degree of choice under which migration decisions are made, while
policy interventions can remove barriers and expand the alternatives for
safe, orderly and regular migration that allows vulnerable people to adapt
to climate change (high confidence). {WGII SPM C.2.12, WGII TS.D.8.6,
WGII Cross-Chapter Box MIGRATE in Chapter 7}
Accelerating commitment and follow-through by the private
sector is promoted for instance by building business cases for
adaptation, accountability and transparency mechanisms, and
monitoring and evaluation of adaptation progress (medium
confidence). |
Increasing adaptive capacity minimises
risk associated with involuntary migration and immobility and improves
the degree of choice under which migration decisions are made, while
policy interventions can remove barriers and expand the alternatives for
safe, orderly and regular migration that allows vulnerable people to adapt
to climate change (high confidence). {WGII SPM C.2.12, WGII TS.D.8.6,
WGII Cross-Chapter Box MIGRATE in Chapter 7}
Accelerating commitment and follow-through by the private
sector is promoted for instance by building business cases for
adaptation, accountability and transparency mechanisms, and
monitoring and evaluation of adaptation progress (medium
confidence). Integrated pathways for managing climate risks will
be most suitable when so-called ‘low-regret’ anticipatory options are
established jointly across sectors in a timely manner and are feasible
and effective in their local context, and when path dependencies and
maladaptations across sectors are avoided (high confidence). Sustained
adaptation actions are strengthened by mainstreaming adaptation into
institutional budget and policy planning cycles, statutory planning,
monitoring and evaluation frameworks and into recovery efforts
from disaster events (high confidence). Instruments that incorporate
adaptation such as policy and legal frameworks, behavioural incentives,
and economic instruments that address market failures, such as
climate risk disclosure, inclusive and deliberative processes strengthen
adaptation actions by public and private actors (medium confidence).
{WGII SPM C.5.1, WGII SPM C.5.2, WGII TS.D.10.4} |
108
Section 4
Section 1
Section 4
Many mitigation and adaptation actions have multiple synergies
with Sustainable Development Goals (SDGs), but some actions
can also have trade-offs. Potential synergies with SDGs exceed
potential trade-offs. Synergies and trade-offs are context specific
and depend on: means and scale of implementation, intra- and
inter-sectoral interactions, cooperation between countries and regions,
the sequencing, timing and stringency of actions, governance, and
policy design. Eradicating extreme poverty, energy poverty, and
providing decent living standards to all, consistent with near-
term sustainable development objectives, can be achieved
without significant global emissions growth. (high confidence)
{WGII SPM C.2.3, WGII Figure SPM.4b; WGIII SPM B.3.3, WGIII SPM C.9.2,
WGIII SPM D.1.2, WGIII SPM D.1.4, WGIII Figure SPM.8} (Figure 4.5)
Several mitigation and adaptation options can harness near-
term synergies and reduce trade-offs to advance sustainable
development in energy, urban and land systems (Figure 4.5)
(high confidence). Clean energy supply systems have multiple
co-benefits, including improvements in air quality and health.
Heat Health Action Plans that include early warning and response
systems, approaches that mainstream health into food, livelihoods,
social protection, water and sanitation benefit health and well-
being. There are potential synergies between multiple Sustainable
Development Goals and sustainable land use and urban planning
with more green spaces, reduced air pollution, and demand-side
mitigation including shifts to balanced, sustainable healthy diets.
Electrification combined with low-GHG energy, and shifts to public
transport can enhance health, employment, and can contribute to
energy security and deliver equity. Conservation, protection and
restoration of terrestrial, freshwater, coastal and ocean ecosystems,
together with targeted management to adapt to unavoidable impacts
of climate change can generate multiple additional benefits, such as
agricultural productivity, food security, and biodiversity conservation. |
Clean energy supply systems have multiple
co-benefits, including improvements in air quality and health.
Heat Health Action Plans that include early warning and response
systems, approaches that mainstream health into food, livelihoods,
social protection, water and sanitation benefit health and well-
being. There are potential synergies between multiple Sustainable
Development Goals and sustainable land use and urban planning
with more green spaces, reduced air pollution, and demand-side
mitigation including shifts to balanced, sustainable healthy diets.
Electrification combined with low-GHG energy, and shifts to public
transport can enhance health, employment, and can contribute to
energy security and deliver equity. Conservation, protection and
restoration of terrestrial, freshwater, coastal and ocean ecosystems,
together with targeted management to adapt to unavoidable impacts
of climate change can generate multiple additional benefits, such as
agricultural productivity, food security, and biodiversity conservation.
(high confidence) {WGII SPM C.1.1, WGII C.2.4, WGII SPM D.1,
WGII Figure SPM.4, WGII Cross-Chapter Box HEALTH in Chapter 17,
WGII Cross-Chapter Box FEASIB in Chapter 18; WGIII SPM C.4.2,
WGIII SPM D.1.3, WGIII SPM D.2, WGIII Figure SPM.8; SRCCL SPM B.4.6}
When implementing mitigation and adaptation together, and
taking trade-offs into account, multiple co-benefits and synergies
for human well-being as well as ecosystem and planetary health
can be realised (high confidence). There is a strong link between
sustainable development, vulnerability and climate risks. Social safety
nets that support climate change adaptation have strong co-benefits
with development goals such as education, poverty alleviation, gender
inclusion and food security. Land restoration contributes to mitigation
and adaptation with synergies via enhanced ecosystem services and
with economically positive returns and co-benefits for poverty reduction
and improved livelihoods. |
There is a strong link between
sustainable development, vulnerability and climate risks. Social safety
nets that support climate change adaptation have strong co-benefits
with development goals such as education, poverty alleviation, gender
inclusion and food security. Land restoration contributes to mitigation
and adaptation with synergies via enhanced ecosystem services and
with economically positive returns and co-benefits for poverty reduction
and improved livelihoods. Trade-offs can be evaluated and minimised
by giving emphasis to capacity building, finance, technology transfer,
investments; governance, development, context specific gender-based
and other social equity considerations with meaningful participation
of Indigenous Peoples, local communities and vulnerable populations.
(high confidence). {WGII SPM C.2.9, WGII SPM C.5.6, WGII SPM D.5.2,
WGII Cross-Chapter Box on Gender in Chapter 18; WGIII SPM C.9.2,
WGIII SPM D.1.2, WGIII SPM D.1.4, WGIII SPM D.2; SRCCL SPM D.2.2, SRCCL TS.4}
Context
relevant
design
and
implementation
requires
considering people’s needs, biodiversity, and other sustainable
development dimensions (very high confidence). Countries at
all stages of economic development seek to improve the well-being
of people, and their development priorities reflect different starting
points and contexts. Different contexts include but are not limited to
social, economic, environmental, cultural, or political circumstances,
resource endowment, capabilities, international environment, and prior
development. n regions with high dependency on fossil fuels for, among
other things, revenue and employment generation, mitigating risks for
sustainable development requires policies that promote economic and
energy sector diversification and considerations of just transitions
principles, processes and practices (high confidence). For individuals and
households in low-lying coastal areas, in Small Islands, and smallholder
farmers transitioning from incremental to transformational adaptation
can help overcome soft adaptation limits (high confidence). |
Countries at
all stages of economic development seek to improve the well-being
of people, and their development priorities reflect different starting
points and contexts. Different contexts include but are not limited to
social, economic, environmental, cultural, or political circumstances,
resource endowment, capabilities, international environment, and prior
development. n regions with high dependency on fossil fuels for, among
other things, revenue and employment generation, mitigating risks for
sustainable development requires policies that promote economic and
energy sector diversification and considerations of just transitions
principles, processes and practices (high confidence). For individuals and
households in low-lying coastal areas, in Small Islands, and smallholder
farmers transitioning from incremental to transformational adaptation
can help overcome soft adaptation limits (high confidence). Effective
governance is needed to limit trade-offs of some mitigation options
such as large scale afforestation and bioenergy options due to risks
from their deployment for food systems, biodiversity, other ecosystem
functions and services, and livelihoods (high confidence). Effective
governance requires adequate institutional capacity at all levels
(high confidence). {WGII SPM B.5.4, WGII SPM C.3.1, WGII SPM
C.3.4; WGIII SPM D.1.3, WGIII SPM E.4.2; SR1.5 SPM C.3.4,
SR1.5 SPM C.3.5, SR1.5 SPM Figure SPM.4, SR1.5 SPM D.4.3,
SR1.5 SPM D.4.4}
4.6 Co-Benefits of Adaptation and Mitigation for Sustainable Development Goals
Mitigation and adaptation actions have more synergies than trade-offs with Sustainable Development Goals
(SDGs). Synergies and trade-offs depend on context and scale of implementation. Potential trade-offs can be
compensated or avoided with additional policies, investments and financial partnerships. (high confidence) |
109
Near-Term Responses in a Changing Climate
Section 4
Near-term adaptation and mitigation actions have more synergies
than trade-offs with Sustainable Development Goals (SDGs)
Synergies and trade-offs depend on context and scale
Energy systems
SDGs
Urban and infrastructure
Land system
Ocean
ecosystems
Society,
livelihoods, and
economies
Industry
Adaptation
Mitigation
Adaptation
Mitigation
Adaptation
Mitigation
Adaptation
Adaptation
Mitigation
Limited evidence/no evidence/no assessment
Both synergies and trade-offs/mixed
Trade-offs
Synergies
Key
Figure 4.5: Potential synergies and trade-offs between the portfolio of climate change mitigation and adaptation options and the Sustainable Development
Goals (SDGs). This figure presents a high-level summary of potential synergies and trade-offs assessed in WGII Figure SPM.4b and WGIII Figure SPM.8, based on the qualitative and
quantitative assessment of each individual mitigation or option. The SDGs serve as an analytical framework for the assessment of different sustainable development dimensions, which
extend beyond the time frame of 2030 SDG targets. Synergies and trade-offs across all individual options within a sector/system are aggregated into sector/system potentials for the
whole mitigation or adaptation portfolio. The length of each bar represents the total number of mitigation or adaptation options under each system/sector. The number of adaptation
and mitigation options vary across system/sector, and have been normalised to 100% so that bars are comparable across mitigation, adaptation, system/sector, and SDGs. Positive
links shown in WGII Figure SPM.4b and WGIII Figure SPM.8 are counted and aggregated to generate the percentage share of synergies, represented here by the blue proportion
within the bars. Negative links shown in WGII Figure SPM.4b and WGIII Figure SPM.8 are counted and aggregated to generate the percentage share of trade-offs and is represented
by orange proportion within the bars. |
Synergies and trade-offs across all individual options within a sector/system are aggregated into sector/system potentials for the
whole mitigation or adaptation portfolio. The length of each bar represents the total number of mitigation or adaptation options under each system/sector. The number of adaptation
and mitigation options vary across system/sector, and have been normalised to 100% so that bars are comparable across mitigation, adaptation, system/sector, and SDGs. Positive
links shown in WGII Figure SPM.4b and WGIII Figure SPM.8 are counted and aggregated to generate the percentage share of synergies, represented here by the blue proportion
within the bars. Negative links shown in WGII Figure SPM.4b and WGIII Figure SPM.8 are counted and aggregated to generate the percentage share of trade-offs and is represented
by orange proportion within the bars. ‘Both synergies and trade-offs’ shown in WGII Figure SPM.4b WGIII Figure SPM.8 are counted and aggregated to generate the percentage share
of ‘both synergies and trade-off’, represented by the striped proportion within the bars. The ‘white’ proportion within the bar indicates limited evidence/ no evidence/ not assessed.
Energy systems comprise all mitigation options listed in WGIII Figure SPM.8 and WGII Figure SPM.4b for adaptation. Urban and infrastructure comprises all mitigation options listed |
110
Section 4
Section 1
Section 4
in WGIII Figure SPM.8 under Urban systems, under Buildings and under Transport and adaptation options listed in WGII Figure SPM.4b under Urban and infrastructure systems. Land
system comprises mitigation options listed in WGIII Figure SPM.8 under AFOLU and adaptation options listed in WGII Figure SPM.4b under Land and ocean systems: forest-based
adaptation, agroforestry, biodiversity management and ecosystem connectivity, improved cropland management, efficient livestock management, water use efficiency and water
resource management. Ocean ecosystems comprises adaptation options listed in WGII Figure SPM.4b under Land and ocean systems: coastal defence and hardening, integrated
coastal zone management and sustainable aquaculture and fisheries. Society, livelihood and economies comprises adaptation options listed in WGII Figure SPM.4b under Cross-
sectoral; Industry comprises all those mitigation options listed in WGIII Figure SPM.8 under Industry. SDG 13 (Climate Action) is not listed because mitigation/ adaptation is being
considered in terms of interaction with SDGs and not vice versa (SPM SR1.5 Figure SPM.4 caption). The bars denote the strength of the connection and do not consider the strength
of the impact on the SDGs. The synergies and trade-offs differ depending on the context and the scale of implementation. Scale of implementation particularly matters when there is
competition for scarce resources. For the sake of uniformity, we are not reporting the confidence levels because there is knowledge gap in adaptation option wise relation with SDGs
and their confidence level which is evident from WGII fig SPM.4b. {WGII Figure SPM.4b; WGIII Figure SPM.8}
Effective climate governance enables mitigation and adaptation
by providing overall direction based on national circumstances,
setting targets and priorities, mainstreaming climate action across
policy domains and levels, based on national circumstances and
in the context of international cooperation. |
The bars denote the strength of the connection and do not consider the strength
of the impact on the SDGs. The synergies and trade-offs differ depending on the context and the scale of implementation. Scale of implementation particularly matters when there is
competition for scarce resources. For the sake of uniformity, we are not reporting the confidence levels because there is knowledge gap in adaptation option wise relation with SDGs
and their confidence level which is evident from WGII fig SPM.4b. {WGII Figure SPM.4b; WGIII Figure SPM.8}
Effective climate governance enables mitigation and adaptation
by providing overall direction based on national circumstances,
setting targets and priorities, mainstreaming climate action across
policy domains and levels, based on national circumstances and
in the context of international cooperation. Effective governance
enhances monitoring and evaluation and regulatory certainty,
prioritising inclusive, transparent and equitable decision-making,
and improves access to finance and technology (high confidence).
These functions can be promoted by climate-relevant laws and
plans, which are growing in number across sectors and regions,
advancing mitigation outcomes and adaptation benefits (high
confidence). Climate laws have been growing in number and
have helped deliver mitigation and adaptation outcomes (medium
confidence). {WGII SPM C.5, WGII SPM C.5.1, WGII SPM C5.4, WGII SPM C.5.6;
WGIII SPM B.5.2, WGIII SPM E.3.1}
Effective
municipal,
national
and
sub-national
climate
institutions, such as expert and co-ordinating bodies, enable
co-produced, multi-scale decision-processes, build consensus
for action among diverse interests, and inform strategy settings
(high confidence). This requires adequate institutional capacity at
all levels (high confidence). |
Climate laws have been growing in number and
have helped deliver mitigation and adaptation outcomes (medium
confidence). {WGII SPM C.5, WGII SPM C.5.1, WGII SPM C5.4, WGII SPM C.5.6;
WGIII SPM B.5.2, WGIII SPM E.3.1}
Effective
municipal,
national
and
sub-national
climate
institutions, such as expert and co-ordinating bodies, enable
co-produced, multi-scale decision-processes, build consensus
for action among diverse interests, and inform strategy settings
(high confidence). This requires adequate institutional capacity at
all levels (high confidence). Vulnerabilities and climate risks are often
reduced through carefully designed and implemented laws, policies,
participatory processes, and interventions that address context
specific inequities such as based on gender, ethnicity, disability, age,
location and income (high confidence). Policy support is influenced by
Indigenous Peoples, businesses, and actors in civil society, including,
youth, labour, media, and local communities, and effectiveness is
enhanced by partnerships between many different groups in society
(high confidence). Climate-related litigation is growing, with a large
number of cases in some developed countries and with a much smaller
number in some developing countries, and in some cases has influenced
the outcome and ambition of climate governance (medium confidence).
{WGII SPM C2.6, WGII SPM C.5.2, WGII SPM C.5.5, WGII SPM C.5.6,
WGII SPM D.3.1; WGIII SPM E3.2, WGIII SPM E.3.3}
Effective climate governance is enabled by inclusive decision
processes, allocation of appropriate resources, and institutional
review, monitoring and evaluation (high confidence). |
Climate-related litigation is growing, with a large
number of cases in some developed countries and with a much smaller
number in some developing countries, and in some cases has influenced
the outcome and ambition of climate governance (medium confidence).
{WGII SPM C2.6, WGII SPM C.5.2, WGII SPM C.5.5, WGII SPM C.5.6,
WGII SPM D.3.1; WGIII SPM E3.2, WGIII SPM E.3.3}
Effective climate governance is enabled by inclusive decision
processes, allocation of appropriate resources, and institutional
review, monitoring and evaluation (high confidence). Multi-level,
hybrid and cross-sector governance facilitates appropriate consideration
for co-benefits and trade-offs, particularly in land sectors where decision
processes range from farm level to national scale (high confidence).
Consideration of climate justice can help to facilitate shifting development
pathways towards sustainability. {WGII SPM C.5.5, WGII SPM C.5.6,
WGII SPM D.1.1, WGII SPM D.2, WGII SPM D.3.2; SRCCL SPM C.3,
SRCCL TS.1}
Drawing on diverse knowledge and partnerships, including
with women, youth, Indigenous Peoples, local communities, and
ethnic minorities can facilitate climate resilient development
and has allowed locally appropriate and socially acceptable
solutions (high confidence). {WGII SPM D.2, D.2.1}
Many regulatory and economic instruments have already been
deployed successfully. These instruments could support deep
emissions reductions if scaled up and applied more widely.
Practical experience has informed instrument design and helped to
improve predictability, environmental effectiveness, economic efficiency,
and equity. |
{WGII SPM C.5.5, WGII SPM C.5.6,
WGII SPM D.1.1, WGII SPM D.2, WGII SPM D.3.2; SRCCL SPM C.3,
SRCCL TS.1}
Drawing on diverse knowledge and partnerships, including
with women, youth, Indigenous Peoples, local communities, and
ethnic minorities can facilitate climate resilient development
and has allowed locally appropriate and socially acceptable
solutions (high confidence). {WGII SPM D.2, D.2.1}
Many regulatory and economic instruments have already been
deployed successfully. These instruments could support deep
emissions reductions if scaled up and applied more widely.
Practical experience has informed instrument design and helped to
improve predictability, environmental effectiveness, economic efficiency,
and equity. (high confidence) {WGII SPM E.4; WGIII SPM E.4.2}
Scaling up and enhancing the use of regulatory instruments,
consistent with national circumstances, can improve mitigation
outcomes in sectoral applications (high confidence), and
regulatory instruments that include flexibility mechanisms
can reduce costs of cutting emissions (medium confidence).
{WGII SPM C.5.4; WGIII SPM E.4.1}
Where implemented, carbon pricing instruments have incentivized
low-cost emissions reduction measures, but have been less
effective, on their own and at prevailing prices during the
assessment period, to promote higher-cost measures necessary
for further reductions (medium confidence). Revenue from carbon
taxes or emissions trading can be used for equity and distributional
goals, for example to support low-income households, among other
4.7 Governance and Policy for Near-Term Climate Change Action
Effective climate action requires political commitment, well-aligned multi-level governance and institutional
frameworks, laws, policies and strategies. It needs clear goals, adequate finance and financing tools, coordination
across multiple policy domains, and inclusive governance processes. |
{WGII SPM C.5.4; WGIII SPM E.4.1}
Where implemented, carbon pricing instruments have incentivized
low-cost emissions reduction measures, but have been less
effective, on their own and at prevailing prices during the
assessment period, to promote higher-cost measures necessary
for further reductions (medium confidence). Revenue from carbon
taxes or emissions trading can be used for equity and distributional
goals, for example to support low-income households, among other
4.7 Governance and Policy for Near-Term Climate Change Action
Effective climate action requires political commitment, well-aligned multi-level governance and institutional
frameworks, laws, policies and strategies. It needs clear goals, adequate finance and financing tools, coordination
across multiple policy domains, and inclusive governance processes. Many mitigation and adaptation policy
instruments have been deployed successfully, and could support deep emissions reductions and climate resilience
if scaled up and applied widely, depending on national circumstances. Adaptation and mitigation action benefits
from drawing on diverse knowledge. (high confidence) |
111
Near-Term Responses in a Changing Climate
Section 4
4.8.1. Finance for Mitigation and Adaptation Actions
Improved availability and access to finance157 will enable
accelerated climate action (very high confidence). Addressing
needs and gaps and broadening equitable access to domestic and
international finance, when combined with other supportive actions, can
act as a catalyst for accelerating mitigation and shifting development
pathways (high confidence). Climate resilient development is enabled
by increased international cooperation including improved access
to financial resources, particularly for vulnerable regions, sectors
and groups, and inclusive governance and coordinated policies (high
confidence). Accelerated international financial cooperation is a critical
enabler of low-GHG and just transitions, and can address inequities in
access to finance and the costs of, and vulnerability to, the impacts of
climate change (high confidence). |
Finance for Mitigation and Adaptation Actions
Improved availability and access to finance157 will enable
accelerated climate action (very high confidence). Addressing
needs and gaps and broadening equitable access to domestic and
international finance, when combined with other supportive actions, can
act as a catalyst for accelerating mitigation and shifting development
pathways (high confidence). Climate resilient development is enabled
by increased international cooperation including improved access
to financial resources, particularly for vulnerable regions, sectors
and groups, and inclusive governance and coordinated policies (high
confidence). Accelerated international financial cooperation is a critical
enabler of low-GHG and just transitions, and can address inequities in
access to finance and the costs of, and vulnerability to, the impacts of
climate change (high confidence). {WGII SPM C.1.2, WGII SPM C.3.2,
WGII SPM C.5, WGII SPM C.5.4, WGII SPM D.2, WGII SPM D.3.2,
WGII SPM D.5, WGII SPM D.5.2; WGIII SPM B.4.2,WGIII SPM B.5,
WGIII SPM B.5.4, WGIII SPM C.4.2, WGIII SPM C.7.3, WGIII SPM C.8.5,
WGIII SPM D.1.2, WGIII SPM D.2.4, WGIII SPM D.3.4, WGIII SPM E.2.3,
WGIII SPM E.3.1, WGIII SPM E.5, WGIII SPM E.5.1, WGIII SPM E.5.2,
WGIII SPM E.5.3, WGIII SPM E.5.4, WGIII SPM E.6.2}
Both adaptation and mitigation finance need to increase many-fold,
to address rising climate risks and to accelerate investments in
emissions reduction (high confidence). |
Increased finance would
address soft limits to adaptation and rising climate risks while also averting
157 Finance can originate from diverse sources, singly or in combination: public or private, local, national or international, bilateral or multilateral, and alternative sources
(e.g., philanthropic, carbon offsets). It can be in the form of grants, technical assistance, loans (concessional and non-concessional), bonds, equity, risk insurance and financial
guarantees (of various types).
some related losses and damages, particularly in vulnerable developing
countries (high confidence). Enhanced mobilisation of and access to
finance, together with building capacity, are essential for implementation
of adaptation actions and to reduce adaptation gaps given rising risks
and costs, especially for the most vulnerable groups, regions and sectors
(high confidence). Public finance is an important enabler of adaptation
and mitigation, and can also leverage private finance (high confidence).
Adaptation funding predominately comes from public sources, and
public mechanisms and finance can leverage private sector finance by
addressing real and perceived regulatory, cost and market barriers, for
instance via public-private partnerships (high confidence). Financial and
technological resources enable effective and ongoing implementation
of adaptation, especially when supported by institutions with a strong
understanding of adaptation needs and capacity (high confidence).
Average annual modelled mitigation investment requirements for
2020 to 2030 in scenarios that limit warming to 2°C or 1.5°C are a
factor of three to six greater than current levels, and total mitigation
investments (public, private, domestic and international) would need
to increase across all sectors and regions (medium confidence). Even
if extensive global mitigation efforts are implemented, there will be a
large need for financial, technical, and human resources for adaptation
(high confidence). |
Financial and
technological resources enable effective and ongoing implementation
of adaptation, especially when supported by institutions with a strong
understanding of adaptation needs and capacity (high confidence).
Average annual modelled mitigation investment requirements for
2020 to 2030 in scenarios that limit warming to 2°C or 1.5°C are a
factor of three to six greater than current levels, and total mitigation
investments (public, private, domestic and international) would need
to increase across all sectors and regions (medium confidence). Even
if extensive global mitigation efforts are implemented, there will be a
large need for financial, technical, and human resources for adaptation
(high confidence). {WGII SPM C.1.2, WGII SPM C2.11, WGII SPM C.3,
WGII SPM C.3.2, WGII SPM C3.5, WGII SPM C.5, WGII SPM C.5.4,
WGII SPM D.1, WGII SPM D.1.1, WGII SPM D.1.2, WGII SPM C.5.4;
WGIII SPM D.2.4, WGIII SPM E.5, WGIII SPM E.5.1, WGIII 15.2}
(Section 2.3.2, 2.3.3, 4.4, Figure 4.6)
approaches (high confidence). There is no consistent evidence that
current emission trading systems have led to significant emissions
leakage (medium confidence). |
There is no consistent evidence that
current emission trading systems have led to significant emissions
leakage (medium confidence). {WGIII SPM E4.2, WGIII SPM E.4.6}
Removing fossil fuel subsidies would reduce emissions, improve
public revenue and macroeconomic performance, and yield
other environmental and sustainable development benefits such
as improved public revenue, macroeconomic and sustainability
performance; subsidy removal can have adverse distributional
impacts especially on the most economically vulnerable
groups which, in some cases, can be mitigated by measures
such as re-distributing revenue saved, and depend on national
circumstances (high confidence). Fossil fuel subsidy removal is
projected by various studies to reduce global CO2 emissions by 1–4%,
and GHG emissions by up to 10% by 2030, varying across regions
(medium confidence). {WGIII SPM E.4.2}
National policies to support technology development, and
participation in international markets for emission reduction,
can bring positive spillover effects for other countries
(medium confidence), although reduced demand for fossil fuels as
a result of climate policy could result in costs to exporting countries
(high confidence). Economy-wide packages can meet short-term
economic goals while reducing emissions and shifting development
pathways towards sustainability (medium confidence). Examples
are public spending commitments; pricing reforms; and investment
in education and training, R&D and infrastructure (high confidence).
Effective policy packages would be comprehensive in coverage,
harnessed to a clear vision for change, balanced across objectives,
aligned with specific technology and system needs, consistent
in terms of design and tailored to national circumstances (high
confidence). {WGIII SPM E4.4, WGIII SPM 4.5, WGIII SPM 4.6}
4.8 Strengthening the Response: Finance, International Cooperation and Technology
Finance, international cooperation and technology are critical enablers for accelerated climate action. If climate
goals are to be achieved, both adaptation and mitigation financing would have to increase many-fold. |
Economy-wide packages can meet short-term
economic goals while reducing emissions and shifting development
pathways towards sustainability (medium confidence). Examples
are public spending commitments; pricing reforms; and investment
in education and training, R&D and infrastructure (high confidence).
Effective policy packages would be comprehensive in coverage,
harnessed to a clear vision for change, balanced across objectives,
aligned with specific technology and system needs, consistent
in terms of design and tailored to national circumstances (high
confidence). {WGIII SPM E4.4, WGIII SPM 4.5, WGIII SPM 4.6}
4.8 Strengthening the Response: Finance, International Cooperation and Technology
Finance, international cooperation and technology are critical enablers for accelerated climate action. If climate
goals are to be achieved, both adaptation and mitigation financing would have to increase many-fold. There is
sufficient global capital to close the global investment gaps but there are barriers to redirect capital to climate
action. Barriers include institutional, regulatory and market access barriers, which can be reduced to address the
needs and opportunities, economic vulnerability and indebtedness in many developing countries. Enhancing
international cooperation is possible through multiple channels. Enhancing technology innovation systems is
key to accelerate the widespread adoption of technologies and practices. (high confidence) |
112
Section 4
Section 1
Section 4
There is sufficient global capital and liquidity to close global
investment gaps, given the size of the global financial system,
but there are barriers to redirect capital to climate action
both within and outside the global financial sector and in the
context of economic vulnerabilities and indebtedness facing
many developing countries (high confidence). For shifts in private
finance, options include better assessment of climate-related risks
and investment opportunities within the financial system, reducing
sectoral and regional mismatches between available capital and
investment needs, improving the risk-return profiles of climate
investments, and developing institutional capacities and local
capital markets. Macroeconomic barriers include, amongst others,
indebtedness and economic vulnerability of developing regions.
(high confidence) {WGII SPM C.5.4; WGIII SPM E.4.2, WGIII SPM E.5,
WGIII SPM E.5.2, WGIII SPM E.5.3}
Scaling up financial flows requires clear signalling from
governments and the international community (high confidence).
Tracked financial flows fall short of the levels needed for
adaptation and to achieve mitigation goals across all sectors and
regions (high confidence). These gaps create many opportunities
and the challenge of closing gaps is largest in developing
countries (high confidence). This includes a stronger alignment of
public finance, lowering real and perceived regulatory, cost and market
barriers, and higher levels of public finance to lower the risks associated
with low-emission investments. Up-front risks deter economically
sound low carbon projects, and developing local capital markets are an
option. Investors, financial intermediaries, central banks and financial
regulators can shift the systemic underpricing of climate-related risks. A
robust labelling of bonds and transparency is needed to attract savers. |
Tracked financial flows fall short of the levels needed for
adaptation and to achieve mitigation goals across all sectors and
regions (high confidence). These gaps create many opportunities
and the challenge of closing gaps is largest in developing
countries (high confidence). This includes a stronger alignment of
public finance, lowering real and perceived regulatory, cost and market
barriers, and higher levels of public finance to lower the risks associated
with low-emission investments. Up-front risks deter economically
sound low carbon projects, and developing local capital markets are an
option. Investors, financial intermediaries, central banks and financial
regulators can shift the systemic underpricing of climate-related risks. A
robust labelling of bonds and transparency is needed to attract savers.
(high confidence) {WGII SPM C.5.4; WGIII SPM B.5.4, WGIII SPM E.4,
WGIII SPM E.5.4, WGIII 15.2, WGIII 15.6.1, WGIII 15.6.2, WGIII 15.6.7}
The largest climate finance gaps and opportunities are in
developing countries (high confidence). Accelerated support
from developed countries and multilateral institutions is a critical
enabler to enhance mitigation and adaptation action and can address
inequities in finance, including its costs, terms and conditions, and
economic vulnerability to climate change. Scaled-up public grants for
mitigation and adaptation funding for vulnerable regions, e.g., in Sub-
Saharan Africa, would be cost-effective and have high social returns
in terms of access to basic energy. Options for scaling up mitigation
and adaptation in developing regions include: increased levels of public
finance and publicly mobilised private finance flows from developed
to developing countries in the context of the USD 100 billion-a-year
goal of the Paris Agreement; increase the use of public guarantees
to reduce risks and leverage private flows at lower cost; local capital
markets development; and building greater trust in international
cooperation processes. |
Accelerated support
from developed countries and multilateral institutions is a critical
enabler to enhance mitigation and adaptation action and can address
inequities in finance, including its costs, terms and conditions, and
economic vulnerability to climate change. Scaled-up public grants for
mitigation and adaptation funding for vulnerable regions, e.g., in Sub-
Saharan Africa, would be cost-effective and have high social returns
in terms of access to basic energy. Options for scaling up mitigation
and adaptation in developing regions include: increased levels of public
finance and publicly mobilised private finance flows from developed
to developing countries in the context of the USD 100 billion-a-year
goal of the Paris Agreement; increase the use of public guarantees
to reduce risks and leverage private flows at lower cost; local capital
markets development; and building greater trust in international
cooperation processes. A coordinated effort to make the post-
pandemic recovery sustainable over the long term through increased
flows of financing over this decade can accelerate climate action,
including in developing regions facing high debt costs, debt distress
and macroeconomic uncertainty. (high confidence) {WGII SPM C.5.2,
WGII SPM C.5.4, WGII SPM C.6.5, WGII SPM D.2, WGII TS.D.10.2;
WGIII SPM E.5, WGIII SPM E.5.3, WGIII TS.6.4, WGIII Box TS.1, WGIII 15.2,
WGIII 15.6}
4.8.2. International Cooperation and Coordination
International cooperation is a critical enabler for achieving
ambitious climate change mitigation goals and climate resilient
development (high confidence). Climate resilient development is
enabled by increased international cooperation including mobilising
and enhancing access to finance, particularly for developing countries,
vulnerable regions, sectors and groups and aligning finance flows
for climate action to be consistent with ambition levels and funding
needs (high confidence). |
International Cooperation and Coordination
International cooperation is a critical enabler for achieving
ambitious climate change mitigation goals and climate resilient
development (high confidence). Climate resilient development is
enabled by increased international cooperation including mobilising
and enhancing access to finance, particularly for developing countries,
vulnerable regions, sectors and groups and aligning finance flows
for climate action to be consistent with ambition levels and funding
needs (high confidence). While agreed processes and goals, such as
those in the UNFCCC, Kyoto Protocol and Paris Agreement, are helping
(Section 2.2.1), international financial, technology and capacity building
support to developing countries will enable greater implementation
and more ambitious actions (medium confidence). By integrating
equity and climate justice, national and international policies can help
to facilitate shifting development pathways towards sustainability,
especially by mobilising and enhancing access to finance for vulnerable
regions, sectors and communities (high confidence). International
cooperation and coordination, including combined policy packages,
may be particularly important for sustainability transitions in emissions-
intensive and highly traded basic materials industries that are exposed
to international competition (high confidence). The large majority of
emission modelling studies assume significant international cooperation
to secure financial flows and address inequality and poverty issues in
pathways limiting global warming. There are large variations in the
modelled effects of mitigation on GDP across regions, depending
notably on economic structure, regional emissions reductions, policy
design and level of international cooperation (high confidence).
Delayed global cooperation increases policy costs across regions
(high confidence). |
By integrating
equity and climate justice, national and international policies can help
to facilitate shifting development pathways towards sustainability,
especially by mobilising and enhancing access to finance for vulnerable
regions, sectors and communities (high confidence). International
cooperation and coordination, including combined policy packages,
may be particularly important for sustainability transitions in emissions-
intensive and highly traded basic materials industries that are exposed
to international competition (high confidence). The large majority of
emission modelling studies assume significant international cooperation
to secure financial flows and address inequality and poverty issues in
pathways limiting global warming. There are large variations in the
modelled effects of mitigation on GDP across regions, depending
notably on economic structure, regional emissions reductions, policy
design and level of international cooperation (high confidence).
Delayed global cooperation increases policy costs across regions
(high confidence). {WGII SPM D.2, WGII SPM D.3.1, WGII SPM D.5.2;
WGIII SPM D.3.4, WGIII SPM C5.4, WGIII SPM C.12.2, WGIII SPM E.6,
WGIII SPM E.6.1, WGIII E.5.4, WGIII TS.4.2, WGIII TS.6.2; SR1.5 SPM D.6.3,
SR1.5 SPM D.7, SR1.5 SPM D.7.3}
The transboundary nature of many climate change risks (e.g., for
supply chains, markets and natural resource flows in food, fisheries,
energy and water, and potential for conflict) increases the need
for climate-informed transboundary management, cooperation,
responses and solutions through multi-national or regional
governance processes (high confidence). Multilateral governance
efforts can help reconcile contested interests, world views and values
about how to address climate change. |
Multilateral governance
efforts can help reconcile contested interests, world views and values
about how to address climate change. International environment and
sectoral agreements, and initiatives in some cases, may help to stimulate
low GHG investment and reduce emissions (such as ozone depletion,
transboundary air pollution and atmospheric emissions of mercury).
Improvements to national and international governance structures
would further enable the decarbonisation of shipping and aviation
through deployment of low-emissions fuels, for example through
stricter efficiency and carbon intensity standards. Transnational
partnerships can also stimulate policy development, low-emissions
technology diffusion, emission reductions and adaptation, by linking sub-
national and other actors, including cities, regions, non-governmental
organisations and private sector entities, and by enhancing interactions
between state and non-state actors, though uncertainties remain over
their costs, feasibility, and effectiveness. International environmental
and sectoral agreements, institutions, and initiatives are helping, and
in some cases may help, to stimulate low GHG emissions investment
and reduce emissions. (medium confidence) {WGII SPM B.5.3, WGII SPM
C.5.6, WGII TS.E.5.4, WGII TS.E.5.5; WGIII SPM C.8.4, WGIII SPM E.6.3,
WGIII SPM E.6.4, WGIII SPM E.6.4, WGIII TS.5.3} |
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