The freshwater boom is over. Our rivers are starting to run dry

[muriel_volestrangler]

We can avert global thirst - but it means cutting carbon emissions by 60%. Sounds ridiculous? Consider the alternative

George Monbiot
Tuesday October 10, 2006
The Guardian

...

The great famines predicted for the 1970s were averted by new varieties of rice, wheat and maize, whose development was known as the "green revolution". They produce tremendous yields, but require plenty of water. This has been provided by irrigation, much of which uses underground reserves. Unfortunately, many of them are being exploited much faster than they are being replenished. In India, for example, some 250 cubic kilometres (a cubic kilometre is a billion cubic metres or a trillion litres) are extracted for irrigation every year, of which about 150 are replaced by the rain. "Two hundred million people facing a waterless future. The groundwater boom is turning to bust and, for some, the green revolution is over."

In China, 100 million people live on crops grown with underground water that is not being refilled: water tables are falling fast all over the north China plain. Many more rely on the Huang He (the Yellow river), which already appears to be drying up as a result of abstraction and, possibly, climate change. Around 90% of the crops in Pakistan are watered by irrigation from the Indus. Almost all the river's water is already diverted into the fields - it often fails now to reach the sea. The Ogallala aquifer that lies under the western and south-western United States, and which has fed much of the world, has fallen by 30 metres in many places. It now produces half as much water as it did in the 1970s.

All this was known before the new paper was published. While climate scientists have been predicting for some time that the wet parts of the world are likely to become wetter and the dry parts drier, they had assumed that overall rainfall would rise, as higher temperatures increase evaporation. At the same time - and for the same reason - soils could become drier. It was unclear what the net effects would be. But the new paper's "drought index" covers both rainfall and evaporation: overall, the world becomes drier.

Even this account - of rising demand and falling supply - does not tell the whole grim story. Roughly half the world's population lives within 60 kilometres of the coast. Eight of the 10 largest cities on earth have been built beside the sea. Many of them rely on underground lenses of fresh water, effectively floating, within the porous rocks, on salt water which has soaked into the land from the sea. As the fresh water is sucked out, the salt water rises and can start to contaminate the aquifer. This is already happening in hundreds of places. The worst case is the Gaza Strip, which relies entirely on underground water that is now almost undrinkable. As the sea level rises as a result of climate change, salt pollution in coastal regions is likely to accelerate.

http://www.guardian.co.uk/commentisfree/story/0,,1891588,00.html

[Jcrowley]

1. Water Wars

K&R

[Uben]

2. Baikal lake in Siberia

It holds 20% of the worlds fresh water supply! It alone could supply the world with fresh water for 20 yrs. Its volume would match that of the Baltic sea or the five American great lakes combined! And, it is remarkably pure water.

I'm not trying to underscore your post, but I was just made aware of this recently. A friend, who was a CIA operative in Russia for 20 yrs during the cold war, made me aware of it. I had never even heard of the lake. I Googled it, and found it quite an intersting read.

[Dora]

3. Who "owns" it?

Just asking.

[muriel_volestrangler]

4. Perhaps - but it would require a massive engineering project

and inter-governmental cooperation to build and run it. It's about 1000 miles from the Yellow River area that Monbiot mentions. He does say projects like that are a possible solution, but their track record isn't great:

Another is to shift water, on a massive scale, to the drying lands. But vast hydro-engineering projects have seldom succeeded in helping the poor. Giant dams and canals - like the Narmada system in India, the Three Gorges in China and Colonel Gadafy's "Great Man-Made River" - are constructed at stupendous cost. Then, when no further glory can be extracted by the government officials and companies who built them, the fiddly work of ensuring the water reaches the poor is forgotten, and the money is wasted. As Fred Pearce shows, perhaps the best method, which in the past has kept cities alive even in the Negev desert, is the small-scale capture of rainwater in ponds and tanks.

It would be a question of how much the Chinese were willing to pay the Russians for water. The Russians might want to consider how much water could be extracted from Lake Baikal without causing problems in it as well.

[PhilYerHead]

5. just google T Bone Pickens, Dallas Billionaire. He Believes in Water.