Canadian leaders visited with U.S. government officials this year to press the case for Keystone XL, an oil pipeline planned by TransCanada to deliver heavy Canadian crude oil to southern U.S. refineries.
The Canadian government and project supporters in the United States say the pipeline would stimulate the North American economy and provide a source of energy security for both countries.
The Natural Resource Defense Council said Wednesday climate policies in Canada are "significantly weak." Its analysis of the pipeline finds it would add more than 900 millions tons of carbon pollution to the atmosphere over its planned 50-year lifespan.
Supporters of the project say the environmental claims are exaggerated. The U.S. government needs to sign off on the project and a State Department draft review said some of the pollution from the Canadian oil industry would be present with or without the pipeline.
U.S. pipeline opponent Bold Nebraska said it joined forces with the Nebraska Farmers Union and local advocates to counter the pipeline with renewable energy projects near Keystone's planned route in the state. It said it would raise a wind turbine and solar power installations on a Nebraska farm Saturday as an act of protest.