OTTAWA -- Canada's contribution to a major United Nations climate change conference later this year will be heavily dependent on actions by provincial and territorial governments.

Provincial governments confirm Environment Canada has been collecting greenhouse-gas reduction measures from across the country as the federal government works toward an end-of-March deadline to ante up for the summit in Paris.

"Canada is actively preparing its intended nationally determined contribution," a spokesman for Environment Minister Leona Aglukkaq said in a recent email.

"As this is a national contribution, the provinces and territories hold many levers for taking action on emissions, so the minister is seeking feedback from her counterparts on how initiatives in their jurisdictions will factor into Canada's overall commitment."

Aglukkaq would not agree to an interview on the subject over the last month and her office provided no additional details. Nor is it yet certain the federal government will meet the March 31 deadline set by the Paris conference organizers.

But with the Conservatives under pressure for refusing to regulate the oil and gas sector -- the country's fastest-growing source of greenhouse gas emissions -- federal-provincial co-operation may be Ottawa's only way to save face on the world stage.

Countries participating in COP21, as December's UN climate conference is known, have been asked to relay their "intended nationally determined contributions" this month. These will serve as a starting point for negotiations that are supposed to conclude with a successor to the 2009 Copenhagen Accord.

Under the Copenhagen agreement, the Harper government committed Canada to cut greenhouse gas emissions 17 per cent below 2005 levels by the year 2020 -- a national target even Environment Canada has concluded won't be met.

However, some of Canada's biggest provinces are meeting or exceeding their own goals for GHG reductions and are increasingly taking matters into their own hands.

Quebec Premier Philippe Couillard was in France this week where French President Francois Hollande publicly stated he would "ensure that Quebec is not only present, but also that it has the opportunity to make its voice heard," at the climate conference.

There's been "a real shift in where the energy is," ever since B.C., Manitoba, Ontario and Quebec were among a group of subnational governments who met on the sidelines of a climate conference in Lima, Peru, last December, said Glen Murray, Ontario's minister of environment and climate change.

The premiers will meet next month in Quebec City at the invitation of Couillard to discuss climate change and a national energy strategy.

A wider group of sub-nationals, including California and several New England states, will meet in July in Toronto, where they hope participants from across the Americas can agree on an 80-per-cent GHG reduction target from 1990 levels by the year 2050.

"At the national level what we are hoping -- and I think minister Aglukkaq has opened up the door to this now -- is that those provincial priorities and plans become reflected in Canada's contribution," for Paris, Murray said in an interview.

David Heurtel, Quebec's minister for sustainable development, environment and climate change, said international climate deals can't be "coming from the top down."

"What we are hoping, and what we've demanded, is that the provincial processes already in place ... that these not only be taken into consideration by the federal government but also that we work collectively," in setting Canada's contribution for the next global climate treaty, Heurtel said in an interview Tuesday.

Heurtel added it is important that Ottawa put its own "concrete measures" into the provincial mix when Canada submits its pre-conference pledge.

The unstated federal role appears not unlike the proposition put forward by Liberal Leader Justin Trudeau, who says he won't impose a national carbon-pricing scheme but will instead encourage provinces to develop their own policies.

Murray argues the experience of the failed Kyoto and Copenhagen negotiations suggests new voices and new leverage are required for COP21 to make meaningful change.

"After 20 years of Council-Of-the-Parties meetings, a lot of us do not think that our national governments will deliver an agreement or -- after several tries, and actually several agreements that didn't amount to any action -- are capable of doing this," said Murray.

"My belief very strongly is that it will be subnational governments and corporations and the NGO community that will deliver this."