Climate Variability and Change in Tropical South America

This chapter provides definitions of what climate variabilityClimate variability and change are and an overview of observed and projected changes in climate in tropical South AmericaTropical South America. We present a review of the findings of the Intergovernmental Panel on Climate ChangeClimate change (IPCC) from the First Report launched in 1990 until the Sixth Report AR6 released in 2021. This review includes the evolution of models, projections and emission scenarios used by the IPCC since the 1990s. We also include a review of observed long term hydroclimate variability for some key regions in tropical South AmericaTropical South America that include biomes such as Pantanal, Amazon, the semiarid lands of Northeast Brazil and the Paraná-Plata river basin. For these regions, the focus is on extremes, such as droughtsDrought and floods. Temperature, rainfallRainfall and droughtDrought projections are assessed from the ensemble of global and regional model projections under global warming scenarios of 1.5 and 4.0 °C for various regions of South America. Finally, we also discuss some societal impacts of climate variabilityClimate variability and change as well as knowledge gaps that need to be filled with new studies.