March 9, 2009 in City

In short term, climate change effects could be boon for farmers

By The Spokesman-Review
 
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Weather pattern

A study by the University of Washington’s Climate Impacts Group shows that between 1948 and 2002, the frost-free period in the Columbia Valley has increased by 29 days. As that trend continues, the Inland Northwest could see more summertime heat.

Jay Cronk looks out over his Valleyford- area farm and sees the same rolling wheat fields he always has.

But things here could change as the climate does. Farmers might see a longer, more productive growing season, according to a new study from the University of Washington.

Cronk said he is skeptical about climate change, but acknowledges that the possibility is a subject of great interest in the farm community.

“To this point I’m not convinced,” he said. “We’ve had dry cycles and wetter cycles over the years.”

A recent study by the Climate Impacts Group based at the University of Washington shows that the Inland Northwest’s non-irrigated grain farms would reap substantial benefits as the climate warms.

Yields for fall-planted winter wheat would increase from 13 to 24 percent through 2050 from a combination of factors, including a longer growing season and higher concentrations of carbon dioxide in the atmosphere, which comes as a byproduct of combustion as well as from natural sources.

That is one of the few bright spots in the study that predicts the following:

•Average temperature would increase by 2.2 degrees after 2020, 3.5 degrees after 2040, and 5.9 degrees after 2080, bringing increased frequency of summer heat waves.

•Snowpack across the Northwest would decrease by 30 percent after 2020 and 40 percent after 2040, reducing available water for hydroelectric generation, irrigation and fisheries. The biggest change would come to the Cascades.

•The acreage burned annually by forest fires would double after 2040 and triple after 2080 because of leaner snowpacks and hotter, drier summers.

Cronk, who farms 2,500 acres, said the key to a successful crop is soil moisture from the combination of rain and snowmelt. “Moisture is usually the limiting factor as far as yield goes,” he said.

The Climate Impacts Group said that the volume of annual precipitation in the Inland Northwest would change only minimally, but the timing and severity of storms would change. Less rain is expected to fall in spring and summer, and more rain would come in the fall, some of it in heavier amounts.

Randy Emtman, Cronk’s neighbor, said that growing grains in a northern climate is “always a race against the clock to get the seed in the ground and get that plant growing.”

The climate study shows that between 1948 and 2002, the frost-free period in the Columbia Valley has increased by 29 days. As that trend continues, the Inland Northwest could see more summertime heat, aggravating stress on later-maturing crops such as spring-planted wheat. The earlier-maturing winter wheat, which is planted in the fall and overwinters beneath the snow, could see substantial increases in yield, the study said. Warmer nighttime temperatures are also likely.

Farmers who seed with drills instead of plows might get another benefit. The Obama administration is looking for ways to remove carbon from the atmosphere in a larger effort to combat climate change. Drill seeding eliminates plowing and allows farmers to leave wheat plant residue on the ground, effectively removing its carbon from the atmosphere. Farmers using that planting method might be eligible for future subsidies or carbon trading.

Carbon dioxide is also a key ingredient in plant photosynthesis. Higher concentrations of the so-called greenhouse gas in the atmosphere should boost plant growth, the study said, and would more than offset any reduced yield from summer heat stress.

While apple and cherry crops also would be helped by increased carbon dioxide, loss of irrigation water from Cascade mountain streams would cut yields 20 to 25 percent after 2020 and 40 to 50 percent after 2080.

With milder overall weather and increasingly severe autumn rains, rivers could flow at higher volumes in the winter. Water volumes in the summer and early autumn would drop due to a lighter snowpack and hotter, drier summers.

As a result, water temperatures in tributaries could warm, and salmon would have trouble migrating successfully to spawning grounds because they are sensitive to temperatures higher than 68 degrees.

Hugh Imhof, a spokesman for Avista Corp., said the company is already looking for ways to replace the potential for lost hydropower with wind power, other renewable energy sources and natural gas turbines. Higher water in the winter and an earlier and shorter spring runoff cannot be stored as easily in lakes and reservoirs to keep hydropower output going over many months. “Fast runoff doesn’t help us,” Imhof said.

While there are still plenty of skeptics, some evidence of climate change can already be seen in temperature trends over the past 50 years. The Spokane region has seen a 2-degree increase in that time, according to the state’s office of climate. The number of 90-degree-plus days each year has increased from about 16 to nearly 22.

Professor Bob Quinn at Eastern Washington University, an expert in meteorology and climate, said he was once among the skeptics about global warming, mainly because the geologic record shows that the earth is subject to dramatic swings over long periods of time. But the pace of warming in recent decades has outstripped what could be expected from natural forces, he said.

“The warming that has occurred since 1990 has been spectacular,” he said. “Its environmental effects are obvious.”

Glaciers are retreating in North America. Sea ice is being lost near both poles. Permafrost is melting in Arctic and subarctic regions.

By comparison, the Inland Northwest should get off with fewer negative effects, Quinn said, because of the moderating influence of the Pacific Ocean, the source of much of the region’s weather, he said.

Quinn said he is often asked why the Inland Northwest has had back-to-back snowy winters if the climate is warming.

Climate change doesn’t stop the earth’s movement around the sun, he said, and the changes predicted by scientists would occur over a period decades, not years.

“Winter is still winter,” he said. “The basic earth-sun climate factors don’t go away.”

Mike Prager can be reached at (509) 459-5454 or by e-mail at mikep@spokesman.com.

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