The IPCC Working Group II contribution to the Sixth Assessment Report addresses the challenges of climate action in the context of sustainable development with a particular focus on climate change impacts, adaptation and vulnerability. This chapter frames the point of departure and key concepts building on the IPCC’s Fifth Assessment Report (IPCC, 2014a, b), the Special Report on Global Warming of 1.5 C (IPCC, 2018b), the Special Report on the Ocean and Cryosphere in a Changing Climate (SROCC)(IPCC, 2019b), and the Special Report on Climate Change and Land (SRCCL)(IPCC, 2019a); as well as the WGI contributions to the Sixth Assessment Report (IPCC, 2021a) and complements the contribution of the WGIII Sixth Assessment Report, which will be published after this report (IPCC, 2022).