Mekong Basin, the total hydropower generation is projected to decline by 3.0% and 29.3% under 1.5°C and 2ºC, respectively . In this context, 1.5°C will come up in 2036 under RCP2.6 and in 2033, under RCP6.0; and 2°C will come up in 2056 under RCP6.0 . In India, hydropower production is projected to increase by up to 25% by the end of the 21st century due to increased temperature and precipitation under the RCP8.5 scenario. However, hydropower production is projected to decline in plants located in snow-dominated rivers due to earlier snowmelt . In Colombia, hydropower production is projected to decrease by ~10% under the RCP4.5 dry scenario by 2050 . In a sub-basin of the Amazon River , dry-season hydropower potential is projected to decline by -7.4 to -5.4% from historical baseline conditions under RCP4.5 . In the São Francisco basin of Brazil, hydropower production is projected to reduce by -15% to -20% by 2100 under the IPCC A1B scenario , which will affect the Brazilian energy mix in the future. In Ecuador, under various policy pathways and dry and wet scenarios under RCP4.5, hydropower production is projected to increase by +7% to +21% or decline by -25% to -44% by 2050 . In Europe, different impacts are projected across different sub-regions . In northern Europe, up to 20% of hydropower potential increases are projected under 3ºC warming; increases of up to 15% and 10% are projected under 2℃ and 1.5°C warming levels. In Mediterranean parts of Europe, hydropower potential reductions of up to -40% are projected under 3℃ warming; while reductions below -10% and -5% are projected under 2ºC and 1.5℃ warming levels, respectively . Hydropower plants in Switzerland are projected to lose ~1.0 TWh of hydroelectricity production per year by 2070-2090 due to net glacier mass loss in the earlier part of the century . In the Italian Alps, under the warmest scenario of RCP8.4, up to 4% decreases in hydropower production are projected . The magnitude of change differs significantly among models. In California, USA, the average annual hydropower generation is expected to decline by 3.1% under RCP4.5 by 2040-2050, compared to the baseline 2000-2010 . In the Skagit River basin in the USA, hydropower generation is projected to increase by 19% in the winter/spring and decline by 29% in summer by the 2080s .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report