Water withdrawals grew at almost twice the rate of population increase in the twentieth century.

The global water cycle is intensifying due to climate change, with wetter regions generally becoming wetter and drier regions becoming even drier. A 2018 UN reporthighlights that at present, an estimated 3.6 billion people (nearly half the global population) live in areas that are potentially water-scarce at least one month per year, and this population could increase to some 4.8-5.7 billion by 2050.

Rising temperatures will melt at least one-third of the Himalayas' glaciers by the end of the century even if we limit the temperature rise to 1.5°C. Melting glaciers in both the Andes and the Himalayas threatens the water supplies of hundreds of millions people living downstream.

A severe drought in Cape Town in 2018 led to severe water restrictions being put in place. The city came to within just days of turning off its water supply - dubbed 'Day Zero'. Climate scientists have now calculated that climate change has already made a drought this severity go from a one in 300 year event to being a one in a hundred year event. At 2°C of warming a drought of this severity will happen roughly once every 33 years.