Summary

Weather and climate in South America are influenced by a large variety of processes, including land–atmosphere and ocean–atmosphere interactions, orographic effects, and land use distributions. In addition, human activities are inducing climate change in South America in several ways. The contribution of the Working Group I (WGI) to the Sixth Assessment Report (AR6) of the Intergovernmental Panel on Climate Change (IPCC) provides a comprehensive assessment of the scientific evidence published up to 2021, regarding the observed and projected climate changes in South America. An updated synthesis based on results from General Circulation Models (GCMs) of the main projections of climate change in South America published after the IPCC AR6 WGI shows that although GCMs have considerably improved their representation of different aspects of regional climate, they still exhibit systematic errors like the Double Intertropical Convergence Zone bias as well as dry and warm biases in the Amazon and the Andes, respectively. The number of published scientific studies for South America, focused on the physical aspects of regional climate change, has considerably increased since 2021. The most recent literature confirms many of the projections presented in the IPCC AR6 WGI but expands on projections for different aspects of the regional atmospheric circulation and compound extremes. Despite the increasing amount of peer-reviewed literature since 2021, it is important to highlight that projections of annual and seasonal precipitation in South America exhibit large spread and uncertainty. Therefore, the necessity of producing high-resolution projections in South America is key, as is the importance of applying fit-for-purpose analysis focused on the models with physically consistent simulations of regional climate. This could be helpful in the building of the assessment of the physical aspects of climate change in South America to be presented in the next IPCC Assessment Report (AR7).