Renowned climate scientist Andrew Weaver of the University of Victoria in Canada and his colleague Neil Swart have published a study in Nature [subscription required] that concludes that Canada’s oil sands are not as harmful to the environment as previously imagined. The science, once again, is not settled.“Burning the proven reserve [of Alberta’s heavy bitumen] would lead to a warming of 0.03°C,” they write. Canada’s oil sands are said to have 1.8 trillion barrels of oil-in-place, only a small fraction of which is “economically viable.” Burning even the entire 1.8 trillion barrels of oil would result in global temperature increase of only 0.36 degrees Celsius.Much of the backlash against oil sands rightly targets the extremely detrimental environmental effects of extracting the resource, not its use. This study does not take the actual production of the oil sands into account, but it does shed light on the differences in cleanliness of our various sources of energy, from coal to oil to gas. Coal is the real villain, the study concludes, because it is much dirtier than oil or gas. But even this is only part of the picture: “The problem is dependence on fossil fuels.”We will not achieve independence from fossil fuels in the near term, no matter how much we wish we could. The magic unicorns aren’t going to pull the sleigh, and we are going to just have to live with that fact. The tar sands and the Keystone XL pipeline, far from drastically accelerating global warming as some claim, present an opportunity to lower America’s use of the dirtier fossil fuel, coal, and also to source energy from a friendly neighbor.