A 160-kilometre wide dust storm, corn shrivelling in Georgia fields and Texas blackouts are all harbingers of an unstoppable force geophysicists call "perpetual drought."
At least the terrible Dust Bowl years of the 1930s in North America ended, Dr. Richard Seager told the Toronto Star on Thursday. This one won’t.
The U.S. Drought Monitor computer tracking tags the parched conditions in Texas and Oklahoma as an extraordinary drought, with the rest of the stretch from Arizona to Florida not much better.
Losses in Texas alone, to cattle and wheat, could reach $3 billion U.S., state officials said. Rainfall in Oklahoma is 28 per cent of normal.
In parts of Arizona, it’s half of what it should be. The July 5 dust storm, the worst in 30 years, shut down Phoenix Sky Harbour International Airport and coated the city in a crust of dirt.
All 254 counties of Texas have been declared natural disaster areas. In some place, salt buildup on power lines not swept away by rain has caused blackouts.
“The current drought has been running for less than a year,” said Seager of the Earth Institute at Columbia University. The cyclical arrival of the La Niña weather pattern brought it and will eventually move on.
But more ominous and catastrophic is the permanent spike in temperatures that is making southwestern North American too feeble to bounce back.
“Beyond the year-to-year variability, the entire region from California to the southern plains is getting dryer. It may not be more severe than what we have now, but it will be more persistent,” Seager said.
By the middle of this century, he said, the drought state of the southern United States will be permanent.
“There will still be wet years. There will be dry years. But the net flux, which supplies the moisture to the soil, is going to reduce from 20 to 40 per cent.”
Unlike the Dirty Thirties drought, which lasted seven years, the decade-long drought in the 1950s or even the “megadroughts” of the 13th and 16th centuries — all of them La Niña phenomena — this one is triggered by man-made gases.
“As long as the carbon dioxide in the atmosphere stays where it is, we have a new equilibrium,” said Seager.
Even if all CO² emissions dropped to zero overnight “significant drying would still occur.”
And while farmers have compensated for dry spells since the 1930s with irrigation, it’s an expensive and gasoline-burning way to spread water around.
“As the century progresses, it will be harder and harder to keep the productivity up.”
- Lesley Ciarula Taylor, Staff Reporter