In summary, there is high confidence that the magnitude and frequency of floods are projected to increase in many regions, including Asia, central Africa, western Europe, Central and South America and eastern North America, and decrease in northern North America, southern South America, the Mediterranean and eastern Europe. Projected increases in flooding pose increasing risks, with a 1.2-1.8 and 4-5 times increase in global GDP loss at 2°C and 4℃ compared to 1.5℃ warming, respectively . Without adaptation, projected increases in flooding are 1.4 to 2.5 and 2.5 to 3.9 times in global GDP loss at 2°C and 3ºC compared to 1.5℃ warming, respectively . However, regional differences in risks are large because of the strong influence of socioeconomic conditions and significant uncertainty in flood hazard projection. In small river basins and urban areas, there is medium confidence that projected increases in heavy rainfall would contribute to increases in rain-generated local flooding. However, the snowmelt floods are projected to decrease  and occur 25-30 d earlier in the year by the end of the 21st century with RCP8.5 .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report