Keystone XL Pipeline Approval would be a mistake and here is why.

It looks like decades of extracting high-CO2 fuel at a time when we should be winding down such carbon intensive resource exploitation. It looks like decades of oil spills across America's heartland written off as an acceptable side effect of making money. It looks like decades of continued political lobbying against any CO2-limiting regulations.
If approved and built, it looks like the United State is failing to take climate change seriously by virtually guaranteeing the massive Canadian oil sands reserved are exploited. That, I'm afraid, is the real threat of Keystone XL – the loss of US status as a global leader.
As the world looks to 2015 for the establishment of legally binding emissions targets, it is looking to the US for inspiration and leadership. While opponents of carbon regulations routinely point to China and India as an excuse for further inaction, the US is still the dominant force in world politics. If Obama puts his foot down and tells us the pipeline will not be built, he will be telling the world that the  United States is committed to a future powered by clean renewable energy. For better or for worse, as the US goes so goes the planet.

http://www.alternet.org/environment/approving-keystone-xl-could-be-biggest-mistake-obamas-presidency?akid=11468.294211.9_nRJ2&rd=1&src=newsletter953643&t=11