At Copenhagen, Canada cannot put the tar sands ahead of the environment

There are only two likely scenarios, really. One is the “business as usual” scenario, in which the developed countries do not reduce their greenhouse-gas emissions fast enough and the developing countries just let it rip. In the other, the rich countries make big emissions cuts in the next 10 or 15 years, and the developing countries at least cap their emissions. That better future is still ugly in many places—but not in Canada.

Nobody gets away unscathed in the “business as usual” scenario. When British foreign secretary David Miliband revealed the latest numbers from the Met Office’s Hadley Centre (the U.K.’s national weather service) last October, predicting that a world in which emissions go unchecked may see a 4-degree-Celsius rise in average global temperature by 2060, he simply said: “We cannot cope with a 4-degree world.”

Actually, Britain probably could cope. As an island, cooled by the surrounding ocean, it would be only 3 degrees warmer, which means that it would probably still be able to grow enough food to feed itself. That is vital in a 4-degrees-warmer world, because almost nobody will be exporting food anymore.

Oceans cover two-thirds of the planet’s surface and are cooler than the land, so the average temperature over most land areas is higher than the “average global temperature”. The Hadley Centre predicts that a global average of plus-4 degrees means average temperatures 5 to 6 degrees higher in China, India, Southeast Asia, and most of Africa, and up to 8 degrees higher in the Amazon (which would burn, of course).

The result would be a 40-percent fall in world wheat and corn production and a 30-percent fall in rice by 2060—in a world that would, by then, have to feed 2 billion more people. So there would be mass starvation, and waves of desperate refugees trying to move to some country where they can still feed their kids.

Canada’s only land border, fortunately, is with the United States, and the Americans would certainly seal the Mexican border against refugees from further south. They would want Canadian water, though—and we would probably be short of water ourselves, because the further inland and the further north you go, the higher the temperature rise.

The Hadley Centre predicts that the thickly populated parts of Quebec, Ontario, and the eastern Prairies would be an average of 7 degrees hotter than they are today. Alberta, British Columbia, and New Brunswick would be 6 degrees hotter, while Newfoundland, Nova Scotia, and P.E.I., surrounded by sea, might be down around plus 4 or 5.

Would Canada still be a grain exporter at those temperatures? Would it even be able to feed itself? It depends on what happens to the rainfall, not just the temperature, but the answer might be no. Not being self-sufficient in food in a starving world would be a very unpleasant experience.

On the other hand, suppose everybody signs a climate treaty so effective that world emissions of carbon dioxide peak and start to fall again by 2020. The latest study by the Met Office says that would give us a 50-percent chance of halting the warming, a couple of decades later, at plus-2 degrees Celsius. That is the better future, but it still isn’t pretty.

An average global temperature 2 degrees higher means that average temperatures over land would rise around 3 degrees—probably 3.5 degrees in the case of central Canada. If the rain still falls in the same places at the same times, that might leave Canadian food production at the same level or even higher, but closer to the equator it will be a different story.

In the tropics, the heat itself will be the main problem: rice yields collapse, for example, if the temperature is above 35 degrees Celsius during the critical fertilization period. In many places, even 3 degrees extra will push it into the red.

In the subtropics, drought will be the crop killer, as the rainfall shifts further away from the equator. Even the rain that does fall is likely to evaporate again from the hot, dry soil.

A few countries far from the equator, like Russia and Canada, may still be exporting grain at 2 degrees higher, but many of today’s major grain exporters will be out of the business. (Australia is already on the way out.)

Assume a 20-percent loss of global food production and a billion more people by 2030, and we can expect recurring famines in the tropics and the subtropics. Hungry people move, across borders if necessary, and people in less afflicted countries may use force to stop them.

Regimes that cannot feed their people tend to collapse. Failed states and civil wars multiply. There may even be regional wars between countries that share the same river system when the water gets scarce. The 2-degree scenario is ugly and almost inevitable, but Canada would still be safe.

You get big problems closer to the equator at plus-2 degrees. At plus-4, Canada faces catastrophe too. That is the difference, for Canadians, between an effective climate change treaty and a botched one or none at all.

Canadians, including the government, assume that we will be okay no matter what happens on the climate front, so we can afford to put our other interests (like protecting the income from the tar sands) first. It is not true.

Gwynne Dyer’s latest book is Climate Wars, published in Canada by Random House and Vintage.