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In Far North, Peril and Promise
Wood is stacked and ready for the pulp mill at Pine Falls, Manitoba, where some conservation measures are in place.
(By Doug Struck -- The Washington Post)
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"The dilemma," Austman said, "is that we live on a planet with 6 billion people. This land is under increasing pressure."
Turning a Minus Into a Plus
South of the great swath of forest in central Canada, the wrinkles of the land smooth out, stretching toward a straight horizon. The Great Plains are frozen and still in winter. But in Weyburn, 70 miles southeast of Saskatchewan's capital, Regina, pumps bob relentlessly amid the snowy wheat fields, sucking crude oil from a mile underground like a host of mechanical mosquitoes.
What goes back into the ground here heartens some environmentalists. The giant EnCana oil and gas company, which operates more than 700 oil pumps in this field, pumps carbon dioxide deep down to drive more oil out of the porous rocks.
Almost inadvertently, the company has become the world's largest working example of carbon storage, or sequestration, a technique being hailed by international experts as one tool to reduce greenhouse gases. Darcy Cretin, operations superintendent at the EnCana plant, is slightly amused by the environmental scientists who have flocked here to see the maze of pipes, pumps, valves and sensors planted in the prairie.
"We have to keep explaining we are doing this to make more oil," he said. "The carbon sequestration is an extra."
When the oil brought up at Weyburn dwindled after 40 years of pumping, EnCana struck a deal with the Dakota Gasification Co. It owns a plant in Beulah, N.D., that converts coal to natural gas. Combustion at the gasification plant makes carbon dioxide, which was being vented into the air. EnCana offered to buy the gas, and in 1999 the U.S. company built a 200-mile pipeline into Canada. The foot-wide pipe emerges from its underground route at a chain-link fence on the edge of EnCana's property.
The company pumps the carbon dioxide under high pressure into the oil field. The gas acts as a kind of solvent, driving the oil out of porous rock. The greenhouse gas remains underground, leaving buried nearly 5,000 tons a day that would otherwise have gone into the atmosphere.
Experts believe this scheme of carbon storage could be used more widely in cases where the gas could be easily collected at a single point and moved by pipeline to a storage field. The approach would not work where the carbon dioxide could not be collected easily, such as from the tailpipes of moving cars. But nearly 40 percent of the carbon dioxide released to the air comes from big power plants or industrial areas, where the gas could be captured.
A committee of more than 100 experts from the Intergovernmental Panel on Climate Change concluded in 2005 that carbon sequestration has "considerable potential" to help reduce greenhouse gases, and a lengthy study at Weyburn by the International Energy Agency found virtually no leakage. The British Columbia government this month announced that all its coal-fired electric plants will be required to utilize carbon sequestration to eliminate greenhouse gas emissions.
For oilmen such as Cretin, the prospect of helping reduce a greenhouse gas by pumping it underground seems a natural fit.
"This is pretty easy," he said. "It's basic stuff for us."
