While Justin Trudeau continues to extol the virtues of putting a price on carbon pollution, his Liberal Party's preferred mechanism for doing that may not be all that different from what Stephen Harper's Conservatives are already doing: Leaving it up to the provinces.

In an interview with AM980 talk radio in London, Ont., where Trudeau's caucus met at its winter retreat earlier this week, he said it's no longer up to the federal government to impose a particular type of carbon pricing to slow climate change.​

"We've had nine years of Stephen Harper's government where there's been absolutely no leadership on the environmental file, and failing that kind of leadership ... a number of different provinces have moved ahead," he told host Andrew Lawton.

"It's up to the federal government to catch up, and to co-ordinate and make sure Canada is seen as taking this seriously," the Liberal leader said.

But when asked what he would do if he were to win the next election and become prime minister, Trudeau suggested the time had passed for a centralized, federal approach.

"B.C. has a carbon tax, Alberta has picked up a sort of a carbon tax, Ontario's bringing in its own plan. Quebec is part of a cap and trade with some other regions," Trudeau said. "We have 86 per cent of Canadians now living in provinces that have put a price on carbon."

(Trudeau's calculation includes the population of Ontario, which is expected to reveal its carbon pricing strategy very soon.)

"The mechanism through which we do that should be up to various provinces because they've already taken the lead on that, and what the federal government needs to do is co-ordinate that and oversee the implementation," he said.

The Liberal leader's remarks appear to signal that a top-down energy strategy won't be part of the second-generation Trudeau's governing plans. It's about "the need to respect provinces," his team says.

Public praise vs. quiet enabling

While Trudeau appears keen to applaud — and rely on — provincial initiative, the Harper government's ability to meet its emissions targets already relies on provincial government action. It just doesn't make a point of saying so too loudly.

Federal regulations to curb greenhouse gas emissions for some sectors have been delayed for years. In that vacuum, Canada has benefited from provincial emissions regulations and other strategies brought in by premiers engaged in the issue, such as Ontario's decision to shut down its coal plants.

"A lack of federal leadership on climate change has been the main reason Canada has not taken any concerted action to reduce emissions," NDP environment critic Megan Leslie wrote CBC News. "Now, in his first major policy announcement, Justin Trudeau boldly commits to more of the same failure?‎"

"Whether Conservative or Liberal, Canada can't afford another government that refuses to tackle climate change," she said.

Sub-national strategy

Ontario Premier Kathleen Wynne has spoken of the importance of co-ordinated action by sub-national (provincial or municipal) governments, leading up to Canada's participation in the next United Nations climate change meetings in Paris at the end of this year.

The morning after her Jan. 5 meeting with Harper, Wynne said she was pleased that Harper, in his year-end media interviews, said there was more to be done on climate change.

"He and I had never had that conversation previously, and so I think that's some progress," she said.

When Ontario reveals its own plan shortly, it will join the carbon taxes and cap-and-trade system already in place in other jurisdictions.

Trudeau's federal Liberals, working closely with their provincial counterparts on election strategy and a range of other issues, won't want to interfere.

"When we look at our trading partners like the United States, they're really not interested in engaging on energy issues with Canada because they don't think we're taking the environment seriously," Trudeau said.

Canadians worried about the environment are "withholding social licence on many of the projects that are dear to the prime minister," he told the talk radio station. "You cannot actually build a strong economy unless you're being responsible about the environment."

Trudeau is expected to take a similar message to Calgary when he meets with business leaders there early next month.

With files from Catherine Cullen, Susana Mas