Every time the international climate talks roll around, there’s always a major country or two that gets blamed for gumming up the works. During the George W. Bush years, the United States was the popular scapegoat. More recently, China and India have been castigated for refusing any binding limits on their fast-rising carbon pollution. During the Copenhagen talks in 2009, it was Venezuela and Bolivia that were blocking acceptance of the accords. And this time around, Canada seems to have emerged as the villain du jour. Wait, Canada?

(Charlie Riedel/AP)

So what’s going on here? Perhaps Canada feels strongly about the genuine flaws in the existing Kyoto Protocol. One thing to note here, though, is that Canada also has plenty of self-interested reasons to be uneasy about sharp curbs in greenhouse-gas emisisons. In recent years, new technology and higher oil prices have made it profitable for Canada to exploit vast new oil reserves in its Alberta tar sands. Those reserves are now valued at a whopping $14 trillion, and oil companies are already investing hundreds of billions of dollars in Alberta. Even the recent delay in the Keystone XL pipeline, which would have shipped oil from Alberta through the United States down to the Gulf Coast, isn’t likely to derail tar-sands production for long.

Not only is there a lot of money at stake, but it could prove extremely difficult for Canada to reconcile its oil bonanza with a sharp curb on carbon emissions. Partly because the production process is dirtier, the oil from Alberta’s tar sands is some 82 percent more carbon-intensive than regular oil, according to the U.S. EPA. Already, production from those tar sands account for a striking 6.5 percent of Canada’s greenhouse-gas emissions. According to a recent Environment Canada report, the country is on pace to miss its 2020 climate goals — which it agreed to at Copenhagen — in large part because of its rapidly growing oil and gas sector.

And here’s a broader way to look at things: As the University of Chicago’s Ray Pierrehumbert explains, if Canada were to fully exploit its Athabasca oil sands (which would obviously take a long time), it’d likely prove impossible for the world to meet its goal of limiting average temperature rise to 2 degrees Celsius. According to the National Research Council, humans can emit about one-trillion tons of carbon, in total, if we want to avoid warming the planet that much. To date, we’ve emitted about 500 billion tons when you include deforestation. So we’re already halfway there, and will have to emit less than 500 billion more tons for the next 1,000 years. If humans were to burn all remaining, proven reserves of conventional oil, natural gas, and the Alberta tar sands, we’d surpass the one-trillion mark. And that’s not even counting coal — if we keep burning coal on top of all that, we’d shoot well past 2 degrees.

To be clear, that’s a long-term, worst-case scenario for the tar sands. Perhaps not all of that oil will be economically recoverable. Perhaps Canada can find a way to limit emissions from tar-sand production (here are some ideas). Perhaps the country can be persuaded to leave some of that oil in the ground — maybe Canada would, as Kent says, happily ratify a new treaty that was better designed than the Kyoto Protocol and included countries such as the United States, China and India. Still, in recent years, Canada’s self-interest has diverged pretty dramatically from those countries who think unchecked global warming is a disaster that needs to be averted.

Update: Apologies, got my tons and gigatons straightened out.