The question of whether to build an oil pipeline from the tar sands of Alberta, Canada, to refineries in Texas is turning out to be one of the most important political decisions of the year for the Obama administration. It's an agonizing choice because the costs and benefits of building it are so closely balanced; opponents have overstated the environmental risks, and proponents seem oblivious to the consequences of continuing to feed our nation's oil addiction.
The Keystone XL pipeline would run 1,700 miles and cost $7 billion, generating thousands of construction jobs. It would increase oil imports from a stable, friendly neighbor while decreasing U.S. reliance on more volatile (and sometimes hostile) OPEC regimes. What's more, pipelines are the safest way to transport oil.
Yet the tar sands are an environmental monstrosity. To extract the tar-like crude from the sand and clay in which it's embedded, steam must be injected underground to liquefy the oil before pumping it to the surface. Thus it requires a great deal of energy to produce energy, heightening emissions of greenhouse gases. Residents of Nebraska and other states through which the pipeline would pass, meanwhile, fret about the risk of a leak that might contaminate water supplies.