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

[RestoreGore]

The Freshwater Boom Is Over/Our Rivers Are Starting To Run Dry

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

By George Monbiot

It looks dull, almost impenetrable in places. But if its findings are verified, it could turn out to be the most important scientific report published so far this year. In this month's edition of the Journal of Hydrometeorology is a paper written by scientists at the Met Office, which predicts future patterns of rainfall and evaporation. Those who dispute that climate change is taking place, such as Melanie Phillips of the Daily Mail, like to point out that that the predicted effects of global warming rely on computer models, rather than "observable facts". That's the problem with the future - you can't observe it. But to have any hope of working out what might happen, you need a framework of understanding. It's either this or the uninformed guesswork that Phillips seems to prefer.

The models can be tested by means of what climate scientists call backcasting - seeing whether or not they would have predicted changes that have already taken place. The global climate model used by the Met Office still needs to be refined. While it tracks past temperature changes pretty closely, it does not accurately backcast the drought patterns in every region. But it correctly reproduces the total global water trends over the past 50 years. When the same model is used to forecast the pattern over the 21st century, it uncovers "a net overall global drying trend" if greenhouse gas emissions are moderate or high. "On a global basis, drought events are slightly more frequent and of much longer duration by the second half of the 21st century relative to the present day." In these dry, stodgy phrases, we find an account of almost unimaginable future misery.

Many parts of the world, for reasons that have little to do with climate change, are already beginning to lose their water. In When the Rivers Run Dry, Fred Pearce, who is New Scientist's environment consultant, travels around the world trying to assess the state of our water resources. He finds that we survive today as a result of borrowing from the future.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.

snip

As these two effects of climate change - global drying and rising salt pollution - run up against the growing demand for water, and as irrigation systems run dry or become contaminated, the possibility arises of a permanent global food deficit. Even with a net food surplus, 800 million people are malnourished. Nothing I could write would begin to describe what a world in deficit - carrying 9 billion people - would look like.

There are four possible means of adapting to this crisis:

end of excerpt.

George Monbiot's book Heat: How to Stop the Planet Burning is published by Penguin/ monbiot.com

Interview With Fred Pearce
Very good and informative interview on this crisis.

[roamer65]

1. No water diversion from the Great Lakes, period!

We will fight all diversion efforts.

[shireen]

2. there are more efficient ways to use water

hydroponics.

Cornell is doing some incredible research in that area. See http://www.cornellcea.com/ and http://www.earthsky.org/radioshows/48772/growing-lettuce-without-soil
They can produce "20 times more lettuce per square foot per year than the fertile lettuce fields of California."
The project was originally developed to create ways to grow produce locally because of peak oil concerns (too expensive to import fresh produce). I am so impressed with these people. If I could live my life over, I'd be working for Lou Albright who runs that program.

[RestoreGore]

3. Is food grown with hydroponics as nutritious as soil grown food?

I saw a demonstration of hydroponics twenty years ago, but don't know too much about it. Thanks for the links.

[IDemo]

5. Hydroponics produce is more flavorful and likely more nutricious

Doing it at a large scale seems like it would be quite expensive, though.

[RestoreGore]

6. yes, I think it would be as well

But it might be an option in smaller areas that need to save water or are already water scarce.

[Kolesar]

8. The heating vs. transportation calculus

From your first link:

When fresh produce is transported great distances there can be a significant loss of quality. Furthermore, energy requirements for transport can be significant. Local production in CEA facilities can also require significant energy inputs for heating, venting, and possibly, supplemental lighting. Studies have suggested the (non-solar) energy required to grow and transport fresh produce at least 1000 miles is equivalent to the energy required for local production within CEA facilities in cold and cloudy climates such as the Northeast and upper Midwest.

We need to start our own victory gardens. Grow some melons or tomatoes in containers on your porch if you don't have any land to garden.

[ramapo]

4. Water, like gas, is too cheap

We all waste huge amounts of water. It is easy and fairly cheap. We have toilets that use far more water than necessary. We pour incredible amounts onto our lawns and other landscaping, even if we happen to live in a desert. What could be crazier than that? Many of us get water from underground aquifers. People just assume there'll always be water to pump, just like oil. And after all, the water isn't burned so there is a fairly stable amount of this precious resource. Just like oil, people will one day learn to conserve but out of necessity rather than good sense.

[RestoreGore]

7. That seems to be the way of human nature

Very frustrating.