After years in which North America was the leading international holdout against action on climate change, the continental tide appears to have turned – mostly. Only one leader still stands against the international consensus, Canadian Prime Minister Stephen Harper.

The coincidence of national election campaigns running in Canada and the U.S. has given us an unusual opportunity to actually compare our leaders. Beginning with U.S. presidential candidates Barack Obama and John McCain and following with the five major Canadian political leaders, everyone has presented a platform and four of the five include credible action on global warming.

Comparisons are, of course, subjective. Politicians have little to gain by presenting policies that are easy to measure or promises that are easy to test. What can we really conclude when Obama says he will cut U.S. carbon dioxide emissions by 80 per cent from 1990 levels by 2050? Even if he wins and serves two terms, he’ll be long gone before anyone can confirm that pledge.

But Obama’s plan still shows that he takes climate change seriously. John McCain seems to, as well. He, with California Governor Arnold Schwarzenegger, was a leader in declaring that global warming is not a Republican or Democratic issue, but a critical issue for the planet.

In Canada, Liberal leader Stephane Dion, New Democratic Party leader Jack Layton,  Bloc Quebecois leader Gilles Duceppe and Green Party leader Elizabeth May all agree. All have reasonable plans. All promise to reduce CO2 emissions by between 20 and 30 per cent by 2020 – from 1990 levels.

It’s annoying to have to add that qualifier: “from 1990 levels.” But it’s important. Because when Conservative Party leader Stephen Harper promises to cut CO2 emissions 20 per cent, he dodges the internationally accepted start date of 1990, using 2006 instead. But Canada’s emissions rose nearly one-third between 1990 and 2006, which means that Harper is really proposing to reduce emissions by only three per cent from 1990 – and he has no reasonable plan to reach that inadequate target

Harper is out of touch with Canadians on this issue, and he is mistaken if he thinks – as he said recently – that voters have become more “conservative” during his tenure. As the economy has slowed, they may well have become more concerned. They’re certainly worried about the economy. But that doesn’t mean they no longer care about the environment. In pitting environment and economy against one another, Harper is resorting to old-style Conservative thinking. Research clearly shows that Canadians don’t buy it.

In fact, Canadians believe there’s economic opportunity in going green.

European countries are showing the way. Many are reducing CO2 and, at the same time, kick-starting the technological innovations that will lead them to greater prosperity. For example, Danish energy policy made possible the success of windmill maker Vestas, which enjoyed revenues of $8 billion in 2007, equal to the sales of all forest products from all companies in British Columbia. And major businesses like Wal-Mart, General Electric – even Toyota – are also increasing their profits by pursuing green strategies.

Canadians care about the environment, and they care about our international reputation. If, despite these concerns, many appear to be supporting the Harper Conservatives, it should not be mistaken as approval for his environmental disregard.

Leading climate scientists agree that climate change is the biggest environmental issue in human history. It’s not going away. Canadians will call on any government they send to Ottawa to provide strong leadership on this issue, and if it’s Harper, he’ll need to start following the lead of his current competitors.

James Hoggan is co-founder of Canada’s most popular climate change website, DeSmogBlog.com, and president of the Vancouver PR firm Hoggan & Associates.