By Roger Harrabin
Environment analyst, BBC News
Over the past 40 years the world’s population has doubled. Our use of water has quadrupled. Yet the amount of water on Earth has stayed the same.
Less than 1% of the water on planet blue is for humans to drink.
About 2% is locked up in ice. The rest is for the fish.
Seawater is only good to drink for humans who live near the sea and can afford the cash and the energy to take out the salt.
For most of the population this is not an option.
Desalinated water costs maybe 15 times more than regular water. It burns polluting fossil fuel energy, as solar-powered desalination is in its infancy.
No, most places will have to live with the water they’ve got.
Many countries are awash; they’ll be fine. Others are desperately mining fossil H2O that seeped into rocks during the last ice age.
And as underground supplies run dry, water shortage sets in.
Large parts of Africa, Asia and Europe, including the south east of Britain are categorised by the UN as facing water stress or scarcity.