An important feature of the AR6 cycle is a stronger emphasis on the use of future GWLs to support consistency and comparability across the three IPCC Working Groups' contributions to the AR6 and improve communication. The common range of GWLs relative to the 1850 to 1900 period, termed the 'Tier 1' range by WGI, are 1.5, 2.0, 3.0 and 4.0°C. The use of GWLs assists in the comparison of climate states across climate change scenarios  and in assessing the broader literature, as well as for cross-chapter and cross-working group comparisons. They facilitate the integration of climate projections, impacts, adaptation challenges and mitigation challenges within and across the three Working Groups as there is a close connection between the level of global warming and climate change impacts. Of particular interest is the timing of when the 'Tier 1' GWLs are reached, relative to the period 1850-1900, under the five SSP x-y scenarios, as well as RCP scenarios. For climate change impacts and adaptation responses, linking GWLs to RCP and SSP climate projections using a climate information translation resource is of great relevance for the WGII contribution to AR6.
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report