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. (Photo by Craig Allen, U.S. Geological Survey)
The signs of drought were everywhere, from shrivelled rivers and
lakes in the American West to brittle brown lawns and parched farm crops
in the Canadian Prairies.
Even the hardy, drought-tolerant pinyon
pine forests of New Mexico turned grey as they withered and died,
starved of water for far too long
Anyone who weathered the stubborn dry spell that enveloped western
North America from 2000 to 2004 knows it was harsh, but now a group of
researchers has concluded it was the most severe drought in 800 years –
bone-dry conditions that the scientists believe could become the “new
norm” in this vital agricultural region.
“Projections indicate
that drought events of this length and severity will be commonplace
through the end of the 21st century,” the group of 10 scientists from
several American universities and the University of British Columbia
wrote in a study published Sunday in the journal Nature Geoscience.
“Even worse, projections suggest that this drought will become the wet end of a drier hydroclimate period.”
If
so, a “megadrought” that severely cuts crop production could be on the
horizon, the scientists warn. Many farmers now in the throes of an
extreme drought in the U.S. Midwest that is devastating corn and soybean
crops and threatening to send food prices soaring might concur,
although it’s not yet clear whether this dry spell is part of the
broader trend, noted Beverly Law, a professor of global change biology
at Oregon State University and a co-author of the study.
For their
research, the scientists examined historical drought-severity data
based on tree-ring analysis. While there have been many bouts of hot,
dry weather in the West, they found the drought that accompanied the
start of this century was unlike any since 1146 to 1151.
The
2000-04 drought severely affected soil moisture, river levels, crops,
forests and grasslands. Runoff in the upper Colorado River basin was cut
in half and crop productivity in 2,383 counties in the western United
States declined 5 per cent. The drought also reduced the land’s ability
to sequester carbon dioxide, by 51 per cent on average in the western
U.S., Canada and Mexico, the scientists found. As trees, plants and
crops withered, more carbon dioxide was released into the atmosphere.
Although the drought was not as long or as severe in Canada, it still caused widespread economic damage.
An
analysis by the Drought Research Initiative, a temporary program that
pulled together Canadian university and government scientists, found
that agricultural production dropped an estimated $3.6-billion in 2001
and 2002, while net farm income was zero in Alberta and negative in
Saskatchewan in 2002. Facing widespread scarcity of feed and water, many
livestock producers had to sell off some or all of their herd. And in
parts of the Prairies, the soil was so dry it swirled up into a storm of
dust, obscuring the sky and even contributing to some traffic crashes.
Long-time
Saskatchewan farmer Don Connick counts himself lucky during that
drought. He has a small herd of Hereford cattle and grows a variety of
crops, including wheat, barley and alfalfa, on 1,600 acres in the
Cypress Hills, near the boundary with Alberta.
His hay and barley
crop yields were poor those years and farming was a struggle, but he had
more water than others. The Cypress Hills sit at a higher elevation and
generally get more precipitation and cooler temperatures than the
surrounding area.
“We’re in a micro-climate, I guess you can say,” Mr. Connick said.
But
he is worried about what lies ahead if droughts become more common and
more widespread. He has his eye on the parched conditions ravaging the
U.S. Midwest.
“The concern I have is that drought seems to be
heading north,” he said. “We’ve had some pretty significantly wet years
in these last five or six years but we’re not immune to drought here.”
You don’t have to remind Saskatchewan farmer Paul Heglund of that.
Mr.
Heglund farms on 3,600 acres near Consul, southwest of the Cypress
Hills. It’s the same land his grandfather homesteaded 100 years ago and
the region has always been drought-prone, so much so the blistering dry
spell a decade ago doesn’t even stick out in his mind.
Food
producers here long ago adapted to farming with scant water, a reality
more might soon have to confront. Mr. Heglund only seeds half his land
each year to allow moisture to build in the soil.
“It’s kind of second nature,” he said of coping with drought conditions. “We don’t even notice it as something particular.”
By Renata D’Aliesio@The Globe and Mail
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