The new estimates, from scientists at the Stockholm Environment Institute, use different calculations about oil consumption; the authors say the pipeline’s increased supplies of petroleum would lower global oil prices, which would increase consumption and thus pollution.
The State Department, in its environmental impact statement, estimated that the Keystone XL pipeline could increase GHG emissions by 1.3 million to 27.4 million metric tons annually.
The new study says emissions could be 100 million to 110 million metric tons every year, “or four times the upper State Department estimate.”
In a June 2013 speech, President Obama said his administration’s decision on Keystone depends on the pipeline’s net effects on carbon emissions. “The net effects of the pipeline’s impact on our climate will be absolutely critical to determining whether this project is allowed to go forward,” Obama said.