Keystone pollution may be four times estimates: study

The controversial Keystone XL pipeline could result in four times more greenhouse-gas emissions than previously thought, according to a new study by researchers at the Stockholm Environment Institute.

U.S. State Department findings earlier this year that the pipeline would make no significant difference failed to account for an increase in the amount of oil on the market as a result of the proposed infrastructure, the study says.

Such an increase could reduce oil prices, spur consumption and lead to more emissions, write researchers Michael Lazarus and Peter Erickson.

The co-authors used existing data from previous research and international agencies that mathematically illustrate the way oil prices affect consumption.

“We find that approval of the Keystone XL pipeline could lead … to an increase in global GHG emissions four times as big as prior analyses have concluded,” the study says.

"This finding—developed here using a simple supply and demand model—points to the need for greater availability and transparency of oil supply and demand analyses," it says.

Canada's government claims the study's conclusions were derived from false assumptions, according to The Canadian Press.

Ottawa “agrees with the U.S. State Department analysis that Keystone XL will be safer and less emitting than alternative options,” according to an email from Natural Resources Canada quoted by the news agency.

According to the study, Keystone XL’s yearly carbon impact could reach 110 million tonnes versus the State Department’s largest estimate of 27 million tonnes.

The Stockholm Environment Institute is a non-profit, international research group based in Sweden whose work receives both public and private support.