Assessments of water resources and their management

6. What is the specific impact of climate change on water resources?

Climate change has made the water cycle far less predictable - and water availability and quality less reliable - threatening communities, livelihoods, and sustainable development¹¹. Climate change is indeed radically altering the water cycle as the world is becoming:

• Hotter – Higher temperatures are increasing the rate of evaporation from land and plants into the atmosphere, leading to greater demand for irrigation water ;
• Stormier – The frequency and intensity of hurricanes and cyclones are on the rise, resulting in stronger winds, more precipitation, and more recurrent flooding ;
• Wetter – Rising sea levels are increasing the risks associated with storm surges and poor drainage in low-lying coastal areas. Higher sea levels also affect the quality of freshwater resources ;
• Drier – Drought frequency and intensity are increasing, resulting in crop failures, growing water scarcity, and potential famines. Arid zones and deserts will continue to expand ;
• More polluted – Higher temperatures are intensifying the growth of dissolved nutrients in bodies of water, leading to harmful algal blooms, dead zones, and fish kills.