It was big news in Canada when, in 2008, the country slipped from the top-ten list of the world's most peaceful countries (all the way to eleventh). By this year, it was back in eighth, 74 places above the U.S. and, when liberals in the U.S. feel despairing, what dominates their fantasy life but "moving to Canada?"

And yet, today, you could make an argument that Canada has actually become one of the earth's more irresponsible nations -- namely, when it comes to the environment. Indeed, you could argue that the world would be better off if the government in Ottawa was replaced by, say, the one in Brasilia, which has made a far better show of attending to the planet's welfare. It's a tale of physics, chemistry, and most of all economics, and it all starts in the western province of Alberta.

The Province's Tar Sands cover an area larger than the United Kingdom and contain most of the world's supply of bitumen, a particularly sticky form of petroleum that must be heated or diluted before it can be pumped. Because it's so unwieldy, it's only been in recent years that large-scale development of the tar sands have taken place. The steep rise in global oil prices has set off a boom in the region, with all that naturally follows (prostitutes have reported incomes as high as $15,000 a week).

But this is a boom unlike others. It's the first huge oil play of the global-warming era, the first time we've dangerously stepped onto new turf, even though we understand the stakes.

NASA's James Hansen, the earth's premier climatologist, has laid out these stakes with some precision. His team found in 2008 that, if the atmospheric concentration of CO2 exceeds 350 parts per million, we won't be able to have a planet "similar to the one on which civilization exists and to which life on earth is adapted." We're at 390 parts per million right now, and, what do you know, the Arctic is melting rapidly, the atmosphere is getting steadily wetter, and the oceans are turning sharply more acid. Follow Hansen's math a little further: If we wean ourselves from fossil fuels by 2030, then the earth's CO2 levels will begin to fall, and, by century's end, we'll be back near 350. Damage will be done in the meantime, but perhaps survivable damage. And, conveniently, the world's supply of "conventional," easy-to-get-at oil is starting to dwindle: The deposits in places like Saudi Arabia, which were built long before anyone had heard of climate change, are nearing the autumn of their lives. We could, in other words, use this moment of declining oil supply as a spur to make the leap toward renewable energy -- a gut-wrenching leap, but one that, if we landed successfully, would put us in a new world.

But two things could prolong our addiction to the point where irrevocable damage is assured: coal and unconventional oil. If we keep burning these substances, then the atmospheric level of CO2 will continue to rise steadily. Which brings us back to Alberta, currently gearing up to develop more of that unconventional oil. The province's oil minister, Ron Liepert, recently told the Financial Times that Alberta was going "full speed ahead" in an effort to double production by the end of the century; indeed, he said, technological progress might allow the province to find new ways to extract oil from other formations, further increasing production and moving Canada into the top tier of the world's oil producers, alongside Saudi Arabia and Russia. Liepert said his government was "proceeding all out" to find new markets for the oil, and that he was hopeful not only of building a huge new pipeline to the U.S, but also of selling to China, which he said would "take every drop" of the tar sands oil.

The problem? If you could somehow burn all the oil in Alberta overnight (which, thank God, you can't) Hansen's team calculates it would raise the planet's concentration of CO2 by 200 parts per million -- that is, our current 390 parts per million would become almost 600 parts per million, a level not seen since the Miocene Era, about 25 million years ago. But, forgetting the overnight scenario, even just bringing the tar sands steadily online -- adding a big new stream of carbon to the atmosphere -- would make the already hugely difficult job of phasing out emissions essentially impossible. As Hansen wrote in early June in a letter to fellow scientists, "if the tar sands are thrown into the mix, it is essentially game over." The game, in this case, being the planet.

Several thousand miles away south of Alberta, in the Amazon rainforest, things are different. In some sense, the world "discovered" the Amazon as a precious planetary resource at roughly the same time Canada discovered the commercial potential of the tar sands. When the first Rio summit on the environment was held in 1992, the Amazon was one of the stars: It was, one speaker after another insisted, the "lungs of the planet." "Contrary to what Brazilians think, the Amazon is not their property, it belongs to all of us," a young Senator named Al Gore said in those years. That didn't sit easily with Brazil, which is, after all, a very poor country, with a per capita income of under $3,000; its leaders, one after another, have declared, as one would expect, that the Amazon is theirs.

They have also, however, done fairly remarkable things to keep the forest intact. Consider the State of Acre, a fairly good analogue with Alberta: It has set up a remarkable system of controls on forest clearing, using remote sensing satellites to track down violators. It provides subsidies and tax incentives for forest protection; it's joined together with California to provide carbon credits for those who leave trees alone. None of this was easy -- Acre was the state where rubber tapper Chico Mendes was murdered in the early days of the fight over the Amazon. But, after three decades of hard work, Acre -- in the words of Stephen Kretzmann from the Environmental Defense Fund -- is "a good example of what's most needed in the world: vision, pragmatism, and the conviction and persistence to make change even when it seems impossibly difficult and distant."

Brazil as a whole has made remarkable progress: Between 2006 and 2010, the country reduced Amazon deforestation by two-thirds from the previous decade, reducing about one billion tons of greenhouse gas pollution; the annual damage is measured in Rhode Islands now, not Germanys. It still has huge problems -- in fact, there seems to be a surge of deforestation underway this year, and big agricultural interests are currently pressing to weaken the nation's forestry's law. Much hangs in the balance. But President Dilma Roussef is pledging to reduce deforestation by another 80 percent, and to cut the country's greenhouse gas emissions by 40 percent. And Brazil's voters may give her reason to keep those promises: They gave nearly one-fifth of their votes in the last election to Green Party candidate Marina Silva, the former rubber tapper responsible for much of the pathbreaking work in Acre.

Shouldn't Canada feel the same kind of responsibility to keep carbon safely in the ground that Brazil feels to keep its trees rooted? Absolutely. And another important question: Would the world stand by, as it has more or less done as Canada has accessed its tar lands, if Brazil's president promised to find new markets so that "every splinter" of wood her country produced could be sold? It's hard to imagine so.

Exploiting the tar sands is a crime, pure and simple -- and, given the stakes, it is one of the most staggering the world has ever seen. Not surprisingly, given geography and history, Canada has an accomplice in this crime. Most of the petroleum it produces gets sold in the U.S., still the largest market for oil in the world. Early in the Obama administration, the president approved a pipeline to the Midwest that expanded this trade. This year, the U.S. stands poised to open a much larger spigot, the so-called Keystone XL pipeline, which will carry the heavy Canadian bitumen to Texas refineries.

How crucial is the new pipeline project to the tar sands' future? A couple of weeks ago Canadian oilmen gave the verdict to the Globe and Mail. "Unless we get increased [market] access, like with Keystone XL, we're going to be stuck," said Ralph Glass, an economist and vice-president at AJM Petroleum Consultants in Calgary. And here's the quotable Liepert once more: "If there was something that kept me up at night, it would be the fear that before too long we're going to be landlocked in bitumen," he said. "We're not going to be an energy superpower if we can't get the oil out of Alberta." That is to say, there's no use planning this particular bank robbery if there isn't someone to drive the getaway car.

On the face of it, one would suspect Obama to say "no" to a new pipeline for Canadian oil: He ran, of course, as a staunch foe of global warming and, on the eve of his nomination, promised that, in his administration, the "rise of the oceans would begin to slow and the planet begin to heal." And since even the backers of the Keystone pipeline acknowledge it wouldn't cut gas prices (and, indeed, would probably cause them to rise), there's scant political reason to open the gates. But, of course, there's an awful lot of money to be made, and that money exerts incredible political pressure: Transcanada Pipeline, for instance, the main builder of the project, has hired Hillary Clinton's former deputy campaign director as its chief lobbyist, and the secretary of state has said she's "inclined" to approve the project.

Like any other vast expenditure of money, the Keystone pipeline would create jobs (though, by undercutting the emerging renewables industry, it would cost them, too), and it would make us less dependent on foreign oil, if you don't count Canada as foreign. None of that, however, gets around the essential point: to prevent the planet from overheating, you need to keep carbon in the ground. (You also need to keep coal in the ground; Obama offered a dreadful premonition of this decision earlier this year, when he opened federal land in Wyoming to coal-mining -- there's less carbon in the Powder River Basin than in the tar sands, but that one sale was the equivalent of opening 300 new coal-fired power plants).

Which brings us back to the Amazon, and the double standard we are seeing when it comes to environmental politics. Let's say that President Obama was being asked to sign a certificate allowing a pipeline to carry an endless stream of logs from the Amazon. That, too, would create jobs -- but he wouldn't do it. He wouldn't do it because the world understands how crucial the rainforest is to its future, and because we seem to demand more from Brazil than from Canada (or the U.S., for that matter). Someday, perhaps the world will similarly stop thinking about the oil sands as a source of power and money and instead come to terms with its well-defined dangers. The question is whether we'll reach that conclusion before we pour the carbon into the air, or after.

An original version of this piece was first posted on The New Republic.