Keystone ultimatum

‘Our national interest will be served only if [Keystone XL] does not significantly exacerbate the problem of carbon pollution....

The net effect of the pipeline’s impact on our climate will be absolutely critical to determining whether this project is allowed to go forward’

— President Barack Obama

CHARLIE REIDEL / THE ASSOCIATED PRESS The need to curb greenhouse gas emissions was at the fore of U.S. president Barack Obama’s speech Tuesday.