Canadian Leaders Rumble Over Climate Change Plans at Last Night's Debate

The prospect of a federal cap-and-trade system in Canada surfaced Thursday at a debate among three men vying to be prime minister, with Liberal leader Justin Trudeau calling an opponent's plan to implement the scheme "completely non-sensical" and "so unrealistic."

The issue took center stage when the debate moderator asked New Democratic Party leader Thomas Mulcair about his party's previous $21 billion cap-and-trade proposal. Mulcair said his party's strategy to put a legal cap on emissions would have "no such bill," and then lambasted both the Liberals and the ruling Conservatives over their environmental records.

"The Liberals signed Kyoto with no plan, they admitted they had no plan to respect it. … Shamefully, Stephen Harper made Canada the only country in the world to withdraw from the Kyoto protocol," Mulcair said at the event in Calgary hosted by the Globe and Mail. "Now when I'm talking about avoiding leaving a massive debt on the backs of future generations, this is exactly what we're talking about. So yes, we've always believed that the best way to ensure a reduction in greenhouse gases is with what's called a cap-and-trade system."

The NDP leader added that such a system "can guarantee a reduction."

The Conservatives have previously attacked the NDP on their cap-and-trade idea, calling it a carbon tax. But though Mulcair said Thursday evening that a cap-and-trade system, not a carbon tax, is the best way to reduce emissions, the NDP hasn't yet announced how the scheme would work or how much it might cost. And when moderator David Walmsley asked Mulcair the latter question several times directly, Mulcair would not name a price.

Given the opportunity, Trudeau jumped on Mulcair, calling the NDP's cap-and-trade idea "so unrealistic."

"Eighty-six percent of our economy, our four biggest provinces, have actually committed to putting a price on carbon, and they've done it in different ways, which makes Mr. Mulcair's proposal so unrealistic," Trudeau said. "The idea of imposing a bureaucracy out of Ottawa, a cap and trade system on provinces like British Columbia that have already moved forward with a world renowned carbon tax that is actually working for them, is actually a completely non-sensical plan."

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With little federal guidance on renewable energy and emissions reduction, the provinces have taken the lead in Canada. The Liberal leader promised to work with the provinces to reduce emissions.

When his turn came, Prime Minister Stephen Harper didn't miss a beat and again accused his opponents of wanting to implement a carbon tax.

"This is the first government in the Canadian history that has actually been able to see a reduction in our greenhouse gas emissions while at the same time seeing the economy grow, and we're very proud of that. We didn't do that through carbon tax schemes, principally because carbon taxes are not about reducing emissions, carbon taxes are about raising revenue for the government, and in one form or another, that's what the other parties are proposing."

Harper said the federal government had been taking "a regulatory approach" to reduce emissions "so it's not just left to chance."

Speaking from the sidelines, Green party leader Elizabeth May said the debate "touched on climate, but never talked about the urgency."

The leader was barred from participating in the Globe and Mail debate, but vowed to make herself heard on Twitter.

"We need to reduce greenhouse gases dramatically by investing in our municipalities, by reducing waste, improving energy productivity and jumping on board the clean energy revolution," she said in a video posted to Twitter.

Follow Hilary Beaumont on Twitter: @hilarybeaumont