In summary, roughly half of the world's population are assessed as currently subject to severe water scarcity for at least some part of the year due to climatic and non-climatic factors, and this is projected to be exacerbated at higher levels of warming . General water insecurity issues are seen worldwide, particularly in South Asia, North China, Africa and the Middle East, due to high population densities often coupled with low water availability, accessibility, quality and governance . Areas with high water availability can also be water-insecure due to increased flood risk, deteriorated water quality, and poor governance . Future water security will depend on the evolution of all these socioeconomic and governance factors and future regional climate change . The main climate change contribution to water insecurity is the potential for reduced water availability, with a secondary contribution from increased flooding risk . Future socioeconomic conditions are a crucial driver of water insecurity, implying the need for further adaptation to some level of future climate change . However, policy challenges are high in many regions, with uncertainty in the regional climate outcomes being a key factor .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report