CLIMATE CHANGE: Southwestern U.S. Becoming a Dust Bowl

Stephen Leahy

BROOKLIN, Canada, Apr 5 (IPS) - The severe seven-year drought in the Southwestern United States is just the beginning of a new and even drier climate for the region due to climate change, scientists say.

The infamous "dust bowl" conditions of the 1930s will be the norm, with the possibility that the aridity will be unlike anything in the past, according to research published Thursday in Science — one day before the release of another key report by the Inter-Governmental Panel on Climate Change, which also warns that drought-prone areas are likely to become even drier due to global warming.

According to Ming Fang Ting, a senior research scientist at Columbia University’s Lamont-Doherty Earth Observatory and co-author of the Science study, the current drought in the U.S. Southwest is not part of the natural variability in climactic conditions.

"The causes of drought now, and in the future, are different with climate change," Ting told IPS.

Using 19 computer climate models, researchers determined that the U.S. Southwest and parts of Northern Mexico are expected to become much drier. Unlike previous historical droughts that were caused by changes in sea surface temperatures in the Pacific Ocean, the models reveal that climate change will dramatically increase the size of the sub-tropical dry zone around the planet.

These expanding dry zones will be unlike anything seen in the past 150 years and future droughts will be far worse than any since medieval times, the report says. The big difference compared to the past is that many more people are living in these areas, notes Ting.

Despite its water shortages, the Southwest region includes Arizona, Nevada, New Mexico, Colorado and Utah, which are among the fastest growing states in the U.S. Millions live in large cities such as Phoenix and Denver that are nowhere near rivers and exist only because of enormous water projects that dam rivers or pump deep aquifers and route water through canals and pipelines.

The city of Las Vegas, Nevada sits in a valley in the Mojave Desert. Its population has surged to upwards of 2.4 million, when only 25,000 people lived there 50 years ago. In the past five years alone, 330,000 people moved to the city, which has a huge legal gambling industry.

Demographers predict Las Vegas will reach 3.5 million residents by 2012.

"We get about four inches of rain a year on average, it is a desert," said Scott Huntley of the Southern Nevada Water Authority.

Las Vegas gets all of its water from the Colorado River, but the amount of water in the river is down 25 percent because the drought extends to its headwaters in the Rocky Mountains. Reduced snow pack in those mountains and faster melting of the snow in the spring means the seven states that depend on the Colorado’s water will face shortages this year.

"If the new research is showing this will continue or worsen, that’s very sobering," Huntley told IPS.

Sobering to some perhaps, but Las Vegas remains a fantasyland where anything is possible, including enormous artificial lakes and fountains, like the eight-acre Fountains of Bellagio.

Last month, a development company purchased 200 acres of land along Las Vegas Boulevard, where it intends to build "the largest indoor water park in North America", along with an indoor skiing and ice skating facilities, not to mention a tropical-themed casino and two hotels.

More than 40,000 new hotel rooms are expected in the near future, but the city’s famous casinos aren’t the major water users, accounting for only nine percent. Golf courses and residential use, particularly for lawns and gardens, are the biggest consumers.

"Lawns are ridiculous in the desert. We pay two dollars for every square foot of lawn that’s removed (as an incentive)," Huntley said.

The lawn removal programme has been very successful, as have efforts to clean and reuse sewage water. Even with the recent population growth, water use hasn’t climbed, he said.

"The culture is changing," Huntley said. "People accept that we live in a desert."

Despite these and other efforts, Nevada ranks 41st in water consumption among the 50 U.S. states. Like much of the drought-stricken west, between 80 and 90 percent of the region’s water goes to agriculture — cattle, animal feed and vegetables.

"Agriculture will disappear so water can flow to growing urban areas," predicted Karl Flessa, a geoscientist at the University of Arizona. "It’s already happening."

Cities can grow enormously large by reducing agriculture. But on balance, that’s not good for the natural environment, Flessa said in an interview.

Run-off from farm fields and ditches provides water, albeit often of poor quality, for many plant species, creating habitat for animals and birds. Farms also offer more habitat than a sea of red-tiled suburban housing, he said.

Energy costs might slow growth in the region, where both pumping water and air conditioning consume enormous amounts of power. And even though there will be less water and more people in the future, water scarcity won’t halt the growth.

"As we say here, ’water flows uphill to money and power’," Flessa said.

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