Analysis of changes in temperature and precipitation in South American countries and ecoregions: Comparison between reference conditions and three representative concentration pathways for 2050.

Climate change is a global concern, and its impact on environmental variables such as temperature and annual precipitation is unknown spatially in the desert, andes, and rainforest ecoregions of Peru, Ecuador, and Colombia. In this study, we conducted a general review of climate drivers for South America (SA) and explored climate data using the GCM compareR package (General Circulation Models) and average ensembles for temperature and precipitation. Our results showed that all GCMs demonstrated increases in the annual mean temperature (BIO1) and in the mean temperature of the driest quarter (BIO9) for Peru, Ecuador, and Colombia for 2050 in three RCPs (2.6, 4.5, and 8.5). Also, most of the GCMs showed increases in the annual precipitation (BIO12) and the precipitation in the driest quarter (BIO17). We conducted non-parametric tests (Kruskal-Wallis Test) to assess if the medians of temperature and precipitation in the three ecoregions are equal for both the baseline and the climate change scenarios. We rejected the null hypothesis that the medians are equal for both temperatures and precipitation in the baseline vs. 2050 RCPs (2.6, 4.5, and 8.5). A spatial analysis was conducted to visualize the variations in temperature and precipitation between the RCPs versus the baseline, and the spatial variation at the country or ecoregion level can be observed. The annual mean temperature (°C) or annual precipitation (mm) divided by its standard deviation for each ecoregion (M metric) was analyzed to see how much the average temperature or the annual precipitation is relatively large compared to the variability or dispersion of temperatures or precipitation respectively; the average temperature and the annual precipitation for the baseline and the three RCPs are relatively large and associated with the variability or dispersion of their temperatures in the Napo moist forest compared to the other ecoregions. Our study provides important insights into the potential impacts of climate change on these ecosystems. Prospects in the Napo moist forest ecoregion, where significant changes in temperature and humidity have already occurred, and new species have invaded or evolved in the western Amazon rainforest, are particularly highlighted and reflected in terms of risk mitigation, ecosystem restoration, surveillance, and monitoring.