"UPDATE: Without Carbon Controls, We Face Many More Dust Bowls; 2002-2004 Western Drought Was Worst In 800 Years"
Last week, the NY Times online asked me to contribute to their “Room for Debate.” The questions were “Is the current drought raising the possibility of another Dust Bowl? If so, what can we do to prevent it?” My response is below, followed by a terrific new video by Peter Sinclair on “2012 Drought Update.”
UPDATE: At the very end, I’m adding the news release for a new study that makes clear the West is facing, “a new climatology that would make the 21st century climate like mega-droughts of the last millennium,” as the lead scientist put it.
Only one thing can stop ever-worsening Dust Bowls here and around the world — slashing carbon pollution.
Climate scientists have predicted for decades that man-made global warming would worsen droughts and dust storms in the Southwest and around the world because of the combined effects of warming, drying and the melting of snow and ice.
The warming directly dries the soil out. It also leads to earlier snow melt, so less water will be stored on mountain tops for the summer dry season. It also shifts precipitation patterns, expanding the dry subtropics.
All of these predictions are being observed right now and some are occurring faster than scientists expected.
Now, studies project “extreme drought” conditions by midcentury over much of the most productive and densely populated areas on Earth — including southern Europe, Southeast Asia, Brazil, the southwest United States and large parts of Australia and Africa. One study found that those areas would see drought indices far worse than those of our Dust Bowl.
And, by century’s end, we would be 10 degrees or more warmer than the 1930s if we fail to act soon.
A 2009 study found that carbon pollution levels projected after midcentury would lead to “dry-season rainfall reductions in several regions comparable to those of the ‘dust bowl’ era” that are “largely irreversible for 1,000 years after emissions stop.”
The scientific “debate,” such as it is, is how far into the northern Great Plains and Midwest these Dust Bowl conditions will extend.
What can we do about this? The climatologist David Rind, who did pioneering work on drought projection with NASA, said back in 2005 that “if you get drought indices like these, there’s no adaptation that’s possible.”
The fact is human adaptation to prolonged, extreme drought is virtually impossible. Historically, the primary adaptation to dust-bowlification has been abandonment. The word “desert” comes from the Latin desertum for “an abandoned place.”
We aren’t doing a great job of feeding the 7 billion people we have now. How can we lose much of the most productive farmland here and around the world and feed another 2 billion people?
The only sane response is to reduce carbon pollution sharply. To avert the worst of dust-bowlification, we need global carbon pollution to peak early next decade, drop 50 percent below current levels by 2050, and stop entirely by century’s end. Every year we delay adds $500 billion to the cost of action.
My 2011 Nature article last year on “The next dust bowl” is here. Sinclair’s video follows:
Here is the National Snow and Ice Data Center (NSIDC) release, “Turn of the century drought worst in 800 years, study says“:
A new scientific study indicates the turn-of-the-century drought in the North American West was the worst of the last millennium—with major impacts to the carbon cycle and hints of even drier times ahead.
The study, titled “Reduction in carbon uptake during turn of the century drought in western North America,” indicates that the major drought that struck western North America from 2000 to 2004 severely reduced carbon uptake and stressed the region’s water resources, with significant declines in river flows and crop yields. It was published on July 29 in Nature-Geoscience. NSIDC scientist Kevin Schaefer is a co-author on the study, along with Christopher Williams of Northern Arizona University (NAU). The study was led by Christopher Schwalm of NAU, formerly at Clark University.
Researchers found that the turn-of-the-century drought was the most severe region-wide event of its kind since the last mega drought 800 years ago. “The turn-of-the-century drought may be the wetter end of a new climatology that would make the 21st century climate like mega-droughts of the last millennium,” said Schwalm.
Under normal climate conditions North America absorbs carbon dioxide from the atmosphere due to plant growth, offsetting to anthropogenic carbon emissions from the burning of fossil fuels. “Our study shows the turn-of-the-century drought reduced plant uptake by half in western North America,” said Schaefer.
The current drought that has currently engulfed country is as intense in the western United States as the turn of the century drought, but also includes large portions of the Midwest and Eastern United States.
Climate models indicate drought conditions in the American West may be the new normal as the planet warms, expanding the region that is already chronically dry. “This will not only reduce carbon uptake,” says Schaefer, “but will also would trigger a whole host of significant water resource challenges in a region already subject to frequent water shortages.”
And so mega-droughts join the long list of amplifying carbon-cycle feedbacks (see “Forest Feedback: Rising CO2 In Atmosphere Also Speeds Carbon Loss From Forest Soils, Research Finds” and links therein).
Pinyon pine forests near Los Alamos, N.M., had already begun to turn brown from drought stress in the image at left, in 2002, and another photo taken in 2004 from the same vantage point, at right, show them largely grey and dead. (Credit: Photo by Craig Allen, U.S. Geological Survey via Science Daily)