FILE - This March 17, 2014, file photo shows a stake in the ground wrapped with tape that marks the route of the Keystone XL pipeline in Tilden, Neb. The much-debated Keystone XL pipeline could produce four times more global warming pollution than the State Department has calculated, according to scientists at a Swedish research facility. They say the U.S. estimates didn’t take into account that the added oil from the pipeline would drop prices by about $3 a barrel, spurring consumption that would then create more pollution. (AP Photo/Nati Harnik, File)The Associated Press
WASHINGTON – A new study concludes that the much-debated Keystone XL pipeline could produce four times more global warming pollution than the State Department calculated this year.
The proposed pipeline would carry oil from tar sands in western Canada to Texas.
The researchers estimate it would increase world carbon by as much as 121 million tons a year, compared with the department's estimate of 30 million tons.
Study lead author Peter Erickson says the government calculations didn't take into account that the added oil from the pipeline would drop prices. That would spur consumption, which in turn would mean more pollution.
The study was published Sunday by the journal Nature Climate Change.