In the AR6, system transitions are defined as 'the process of changing  from one state or condition to another in a given period of time' . In the climate change solution space, system transitions represent an important mechanism for linking and enabling mitigation, adaptation and sustainable development options and actions . SR1.5C identified the need for rapid and far-reaching transitions in four systems-energy, land and terrestrial ecosystems, urban and infrastructure, and industrial systems  . The SRCCL expanded on this with a focus on terrestrial systems, while SROCC added additional evidence from ocean and cryosphere systems. This section assesses the four system transitions discussed in the SR1.5C assessment in the context of CRD, while also extending the assessment to consider societal transitions as a cross-cutting, fifth transition important for CRD. Literature to support this assessment is also drawn from AR6 regional and sectoral chapters, which is synthesised later in this chapter .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report