The Keystone XL pipeline that would bring petroleum from Canada's tar sands to US terminals in Houston is proving a political headache for President Obama. It pits many of his erstwhile allies -- such as unions and environmentalists -- against each other.
"In May, environmental writer and activist Bill McKibben — pondering a simmering energy issue — asked a NASA scientist to calculate what it would mean for the Earth's climate if Canada extracted all of the petroleum in its rich Alberta oil sands region.
The answer to McKibben's query came a month later: It would push atmospheric carbon concentrations so high that humans would be unable to avert a climate disaster. "It is essentially game over," wrote James E. Hansen, who heads NASA's Goddard Institute for Space Studies and is one of the nation's leading voices against fossil fuel energy.
That was the moment when McKibben — who had already mobilized a global grass-roots climate movement from his home in Vermont — decided to join the fight against the Keystone XL pipeline, which would carry heavy crude oil from Canada's Alberta province to the Gulf Coast. It was a decision that eventually landed McKibben in jail, along with Hansen and more than a thousand other pipeline foes who have been arrested in front of the White House."