The argument in this article is that Keystone XL would create a de minimis increase in emissions compared to what we already generate through all sources including (as the title cheekily states) cows. This is true, and even under more aggressive assumptions it takes a bit of manipulation to get the pipeline up to 1% of US emissions.
But, as was mentioned briefly in the article, all of this is completely irrelevant. Why? Canada is already developing tar sands, and those “extra emissions” are sunk…they will already be emitted, pipeline or not.
I’m against pollution, but this argument is a waste of time, and is hurting our relationship with the country that sells us the most oil. In fact, one could argue the pipeline reduces emissions, because without it the oil sands oil will be shipped, by boats burning bunker fuel, to Asia.