Water shortages affect food, transit, security

A thousand tons of water produces just one ton of grain.

For 15 years, the United Nations has been observing "World Water Day," a time to consider the opportunities and challenges presented by a resource essential to the environment and to humankind.

It's becoming clear now that climate change may be altering the way people and governments think about water.

The UN reported this week that the world's glaciers are melting at "an alarming rate." Like reservoirs, glaciers store water and then release it at predictable rates, around which humans have formed communities and built economies. Agency France-Presse, the French news service, quotes Achim Steiner, executive director of the United Nations Environment Program, as saying:

"Millions if not billions of people depend directly or indirectly on these natural water storage facilities for drinking water, agriculture, industry, and power generation during key parts of the year."

As a result of shrinking glaciers, people will have to change their lifestyles, their farming, even move their homes, Mr. Steiner says. Britain's Sunday Observer further quotes Steiner as saying:

"While I'm always cautious about 'water wars,' certainly the potential for water to become a trigger for more tension and, where there's already conflict, to exacerbate conflict is another issue that's not hypothetical."

Global warming is raising ocean levels, meaning seawater will encroach on wetlands, rivers, and streams, according to recent reports by the US Environmental Protection Agency and the National Research Council (NRC), the research arm of the National Academy of Sciences.

Climate change also could adversely affect transportation, the NRC reported last week. The Associated Press reports:

"The nation's transportation system was built for local conditions based on historical weather data, but those data may no longer be reliable in the face of new weather extremes.… The report notes, for example, that drier conditions are likely in the watersheds supplying the St. Lawrence Seaway and the Great Lakes. The resulting lower water levels would reduce vessel shipping capacity, seriously impairing freight movements in the region, such as occurred during the drought of 1988."

Water also complicates a shift from fossil fuels, researchers pointed out at the recent annual meeting of the American Association for the Advancement of Science. The Toronto Star reports:

"University of Texas professor Michael Webber, an environmental policy specialist, said so-called green fuels for vehicles all require much more water to produce than ordinary gasoline. Conventional oil refineries use comparatively modest amounts of water, largely for cooling.

"Webber said the water required for an alternate fuel vehicle to travel a certain distance can be up to 100 times that required for a gas-powered vehicle. This extra water use stems from the irrigation of crops like corn that are turned into ethanol, or in the production of the electricity for recharging hybrids."

In China, drought has made it difficult to supply reservoir water for irrigation while also providing generating capacity for downstream hydropower dams. Reuters reports:

"The frequency of both the droughts and floods that regularly batter China are expected to increase in a warmer world. And rural demands could compound the impact of short supplies, because China tends to time releases of water to suit the needs of farmers rather than power companies."

Lester Brown, head of the Earth Policy Institute think tank in Washington, is concerned that declining water supplies combined with the push for water-intensive biofuels could be a threat to global food security. Another Reuters story reports:

"The thing to keep in mind is that it takes 1,000 tons of water to produce one ton of grain.... Seventy percent of all the water we use in the world – that we pump from underground or divert from rivers – is used in irrigation. Not everyone has connected the dots to see that a future of water shortages will be a future of food shortages."