Canada has come last on a WWiF scorecard of G8 countries' efforts against climate change. That news would once have elicited at least a slightly surprised response. For several decades, Canada managed to present itself as the friendly giant of environmental issues. The 1989 Protocol on CFCs, an early turning point in combating the depletion of the ozone layer, was born in Montreal, and American environmental campaigners like Al Gore are always quick to heap praise on their northern neighbour.

But these days, Canada is looking increasingly like the dirty one of G8. The WWF report noted that Canada is one of the few countries on the scorecard whose emissions are still rising, and that Canada's Conservative government isn't doing enough to combat climate change.

Maybe some of Canada's new bad-guy image on environmental issues is just a by-product of America's new green image. Obama's presidency was always going to bump the US up a few places on environmental scorecards, almost just out of gratitude that America has at least promised not to so flagrantly and unapologetically deplete the world's natural resources.

But Obama isn't why Canada is losing its green reputation. The real reason lies in the vast Alberta oil sands. In 2008, Alberta's economically recoverable reserves were placed at 173 billion barrels, meaning that only Saudi Arabia outstrips Canada on oil reserves. But unlike Saudi Arabia, in Alberta the oil is literally in the sand. To dig it up and refine it is a process far higher in emissions than the processing of Saudi Arabian oil, and is destroying much of Alberta's northern Boreal forest along the way.

The response to the report in Canada has been less hand-wringing than one might expect. Some dismiss the finding by pointing out that even other environmental organisations have problems with WWF. Others argue that surveys like the WWF's are just penalising countries like Canada and Russia for their geographic realities – smaller countries keep their emissions down by importing oil from Canada, then criticise Canada for producing it, and so on.

On top of the recession's effect on plans for the oil sands, defenders argue that Obama's cap-and-trade proposals would severely impact Canadian oil production because the proposal will heavily penalise those who ship Canadian oil sand bitumen to the United States, given that refining the raw bitumen is so energy-intensive.

But Canada isn't being punished for its geographic reality. It is finally being called out for presenting itself as environmentally friendly, while under the Conservative government green issues have been completely sidelined, if not derided. Before becoming prime minister, Stephen Harper implied that the science of climate change was "tentative and contradictory", called the Kyoto accord a "socialist scheme" and ranted that an "army of Canadians" was needed to defeat it. While he has proposed "made in Canada" solutions to cutting carbon emissions, Harper's main actions have been to cut programmes that promoted renewable energy like wind power. Even plans for the 2010 Winter Olympics in Vancouver risk causing environmental damage to rare forests in the nearby Eagle Ridge Bluffs.

Vancouver is consistently voted one of the world's most liveable cities, and the Canadian government intends to use the Olympics to showcase Canada's pleasant, fresh-aired way of life. But the price Canada is paying to maintain its "friendly giant" facade is increasingly being paid for by the environment.

The fact that Obama's Clean Energy and Security Act will, if passed by Congress, disproportionately hurt oil companies working with Albertan oil sands may feel like American hypocrisy to Canadians who have long watched the US's profligate environmental destruction go unchecked. But while Harper continues to disappoint on his commitments to the environment, someone has to play the bad cop to Canada.