The Impacts of Climate Change on Extreme Precipitation and Temperature Events in Central America and Northern South America: A Case Study of an Inter-Andean Valley

Extreme precipitation and temperature events can have devastating consequences, such as flash floods, droughts, and landslides, as well as impacts on human settlements, water resources, and hydroelectric generation. This study uses high-resolution models to assess the historical and projected changes in extreme precipitation and temperature events in Central America and Northern South America, focusing on the local effects in a tropical highly urbanized Inter-Andean valley. The performance of high-resolution models from the CORDEX (CMIP5) initiative, the High-Resolution Model Intercomparison Project (HighResMIP), and the NASA Earth Exchange Global Daily Downscaled Projections dataset (NEX-GDDP-CMIP6) is assessed in terms of their representation of a set of extreme temperature and precipitation indices, as established by the Expert Team on Climate Change Detection and Indices (ETCCDI). This assessment encompasses the time frame from 1981 to 2005, using temperature data from the ERA5 reanalysis and satellite-derived precipitation information from the CHIRPS datasets. Furthermore, the examined projected changes are performed for two future timeframes (2030–2060 and 2070–2100) under the Shared Socioeconomic Pathways SSP2-4.5 and SSP5–8.5 scenarios. The results of the historical simulations suggest that the NEX-GDDP-CMIP6 and HighResMIP models better represent the patterns of climate indicators for temperature and precipitation across Central America and Northern South America than the CORDEX models. This initial analysis identified adequate models for representing climate projections while highlighting the difficulty of accurately simulating precipitation. Projections for the selected subset of models for the upcoming decades reveal a pronounced warming trend and amplified occurrences of extreme precipitation in the subcontinents under the SSP2-4.5 and SSP5-8.5 scenarios. The magnitude of these changes increases over time, from the 2030-2060 to the 2070-2100 timeframes, and is more significant under the more extreme SSP5-8.5 scenario. These identified trends align coherently with outcomes documented in earlier research.

Moreover, the results suggest that the tropical Inter-Andean Valley and its neighboring region are expected to experience a pronounced warming trend, with average temperatures increasing by 2-3 degrees Celsius by the end of the 21st century. The study also found that the region will experience an increase in the frequency and intensity of extreme precipitation events triggering flash floods, landslides, and failures in drainage systems. On the other hand, the temperature increase will affect the number of days without precipitation, impacting drought occurrences. These projected changes will significantly impact the availability of water resources for human water supply, hydroelectric generation, and soil maintenance. The study found that the impacts of climate change on the tropical Inter-Andean Valley and its neighboring region are likely to be more severe in the more extreme SSP5-8.5 scenario. The study's findings highlight the need for risk management and public policy formulation to mitigate the region's negative impacts of climate change, and the results contribute to the robustness of knowledge for reaching a consensus on these impacts in Central America and North of South America.