Spatial Patterns of CMIP6-Projected Climate Change Across Andean–Amazonian Ecoregions of Northeastern Peru

The Andean–Amazonian transition zone in northeastern Peru is one of the most climatically diverse and complex regions in South America, yet knowledge of its ecoregions under climate change remains limited. This study assessed projected changes in mean annual temperature, accumulated annual precipitation, and incident solar radiation in the Amazonas department using an ensemble of five global climate models from the Coupled Model Intercomparison Project Phase 6 (CMIP6) under the Shared Socioeconomic Pathway (SSP) 2-4.5 and SSP5-8.5 scenarios for the periods 2031–2060 and 2071–2100. Historical data from the NASA Earth Exchange Global Daily Downscaled Projections (NEX-GDDP-CMIP6) were used to analyze the spatial distribution of climate, climate anomalies, variability among ecoregions, and inter-model variability. The results show a generalized temperature increase across the department, with average anomalies between 1.20 and 3.96 °C, while precipitation increased between 3.93 and 16.59%, but with greater spatial heterogeneity and inter-model variability. Solar radiation showed moderate changes, with increases of up to 2.07 W m⁻² toward the end of the century. Ecoregions maintained their climatic differences, but the largest relative increase in precipitation was projected for montane grasslands and shrublands. Temperature showed the greatest agreement in the direction of projected change among models, while precipitation and solar radiation showed greater inter-model variability. These results provide spatially explicit climate information that can contribute to land-use planning, ecosystem conservation, and the design of regional climate change adaptation strategies in the Andean–Amazonian transition zone. These findings may also provide useful climate information for landscape restoration planning and for assessing future ecosystem responses to changing climatic conditions.