The rivers, too, are beginning to run dry. Only a trickle of the Nile now reaches the Mediterranean. The Nile now provides food and water for 153m people. By 2025 it will be the only source of life for 343m humans. As a result, ice caps are retreating.
Many communities depend entirely on glacial meltwater.
The glacier that supplies 10m people in Quito, Ecuador, is retreating by some 30m a year. Because the world is warming, there should be more evaporation. But water vapour is also a greenhouse gas. Either way, climate extremes are expected to increase. Between 1970 and 1994, according to the Red Cross, drought and famine killed or harmed 58m people a year, while floods killed or harmed an average of 56m a year.