Achieving the Paris Agreement would substantially reduce climate change risks to biodiversity in Central and South America

Climate change is one of the greatest threats to biodiversity. Although it might adversely impact all of the world in varying magnitudes, tropical biodiversity is expected to be impacted the most. Central and South America (CSA) is among the most biodiverse regions in the world, housing several important areas for conservation due to high levels of diversity and endemism. Thus, because of its disproportionate tropical biodiversity, CSA might be severely vulnerable to climate change in the future. We performed a systematic review to assess how risk projections varied for different aspects of biodiversity in CSA, and the potential benefits of limiting climate change. We evaluated 71 scientific papers, amounting to > 3000 risk projections in the priority areas for conservation in CSA. CSA houses some of the most studied richspots in the world, with a strong bias towards the Atlantic Forest, Mesoamerica and Cerrado hotspots. Our results indicate that up to 85% of risk projections predict negative impacts, with 26% of projections predicting species extinctions. While high emissions scenarios indicate severe adverse impacts for biodiversity in CSA, noteworthy risk reduction arose from mitigation. Considering a climate change mitigation scenario in line with the Paris Agreement, risks for the region could be substantially reduced by over 80%. However, for endemic species, which are predicted to be the most impacted by climate change in CSA, mitigation alone will not suffice to minimize climatic risks. This highlights the urgent need of adaptation measures to increase the resilience of natural systems in the CSA to climate change.

Automated summary

Climate change poses a significant threat to biodiversity, with tropical biodiversity expected to be most impacted. This study evaluates the risk projections for different aspects of biodiversity in Central and South America (CSA) and the potential benefits of climate change mitigation. The findings suggest that up to 85% of risk projections predict negative impacts, with species extinctions projected in 26% of cases. However, mitigation efforts in line with the Paris Agreement could substantially reduce risks by over 80%, emphasizing the importance of adaptation measures for endemic species in CSA.