Water is a necessity for life. Yet, though life first evolved in the oceans, most terrestrial organisms cannot drink the salt water that makes up over 97 per cent of the world’s total. Of the fresh water that makes up the rest, more than 90 per cent is locked away in glaciers and ice sheets, or hidden deep underground. Only 0.0001 per cent of fresh water is easily accessible; human settlements are clustered along the waterways and fertile floodplains.
This is all the fresh water available to us. It is not created anew but recycled, as the sun evaporates the oceans and water falls back to earth as rain and snow. What we drink is made up of ancient molecules of water that have fed rainforests, slaked the thirsts of dinosaurs and prophets, spent millennia frozen in glaciers. There is enough water in total for us all, but it is unevenly distributed. While the rich world uses more and more, many countries, particularly in Asia and Africa, suffer shortages. A third of the world’s people live in dryland regions that have access to only eight per cent of the world’s renewable water supply.
‘When I was a boy, the ponds and waterholes used to last the whole year through. Now they are dry and empty. When the rains came and filled the oshanas (streams), we used to take our baskets and go fishing. Now the fish baskets hang from the roof poles as ornaments.'
Abraham, from the Cuvelai basin in Namibiaz
For centuries humans dumped waste in the nearest watercourse and drank from it too, but this works only when the waste is small and the people are few. The pollution of waterways by toxic industrial waste and sewage is one of the biggest environmental challenges of our time.
Modern improvements in human health are largely due to great public municipal works of sanitation that provide people with clean drinking water. Access to clean water is still one of the major distinctions between the world’s ‘haves’ and ‘have nots’. The wars of the future are likely to be over fresh water – and sooner than we think.
Meanwhile, as the Earth heats up and the polar ice caps melt, the rising, warming oceans are washing inland, salinizing freshwater tables and flooding human settlements. The oceans are the engines of global weather systems: as they warm, they are not only killing whales and coral reefs, they are triggering storm surges, droughts and new unpredictable weather patterns right across the planet.
WATER – THE FACTS
Photo: Pascal Kobeh /Still Pictures
Photo: Paul Howell / UNEP /Still Pictures
Photo: NRSC / Still Pictures
Photo: Trygve Bolstad / Panos
Photo: Fred Hoogervorst / Panos