"That is something that we've all committed to."

"The transition to a low-carbon economy will happen by a broad suite of measures, which will include pricing carbon,'' Trudeau said at the conclusion of a scheduled five-hour meeting that stretched into more than six.

But the deal hammered out in Vancouver by Trudeau and 13 provincial and territorial leaders appears destined to be relitigated in the months ahead as the hard details of the agreement take shape.

VANCOUVER — Prime Minister Justin Trudeau and the provincial premiers managed to bridge deep divides over carbon pricing Thursday en route to Canada's first national consensus on pursuing climate policy.

Prime Minister Justin Trudeau leads Canada's premiers to a news conference during the First Ministers Meeting in Vancouver, B.C., Thursday, March 3, 2016. (Photo: Jonathan Hayward/CP)

He said the first ministers will reconvene next fall, after four working groups report back on broad policy areas, "where we will finalize a pan-Canadian plan" to combat climate change.

The prime minister readily conceded that the first ministers have challenges ahead.

As B.C. Premier Christy Clark observed, the Vancouver Declaration's agreement to examine carbon pricing mechanisms "can be interpreted pretty broadly."

The federal government had been quietly insisting for weeks that a national carbon price, as promised in the Liberal election platform, would be imposed from above if provinces were unable to agree.

In the end, everyone appeared to get something of what they wanted.

Saskatchewan Premier Brad Wall said the specific language in the eight-page declaration clearly includes "market transactions related to (carbon) mitigation technologies" — a roundabout way of including Saskatchewan's carbon capture and storage (CCS) technology.

"We're doing that already, so that's easy to agree to," said Wall, the most vocal opponent of carbon taxation.

"The fact that we have consensus on the need to include carbon pricing in our approach to addressing climate change right across the country is a great thing indeed."

And he promised a fight if there is "some sort of notion" that there was any agreement here to set carbon taxes.

On the other side of the ledger, a senior federal official quietly grinned when asked about the compromise, saying it was enough to get everyone's signature on a document that includes carbon pricing.

Alberta Premier Rachel Notley said the deal may "sound bureaucratic" but there are tight timelines for the working groups to report and a clear consensus on the need for policy action.

"Everybody was in the room and nobody was debating whether we needed to take action on climate change, no one was really debating whether some form of pricing in some fashion was going to be required to take action on climate change and everybody was very committed to the timelines," said Notley.

In addition to carbon pricing mechanisms, the working groups will examine adaptation and resilience, such as clean infrastructure spending, clean tech innovation and jobs, and climate mitigation strategies.

Environmental advocates and carbon policy experts called the agreement a good start.

"The do-nothing option is not there."

"They got a lot of the big issues right," said Erin Flanagan of the Pembina Institute.

"We'd love to have this all nailed down. But we have to put this in the context of a new federal government. They haven't had all that much time."

Mark Jaccard, an energy economist at Simon Fraser University in Burnaby, B.C., agreed that Saskatchewan's CCS technology does price carbon. He said the challenge for the working groups will be to get mechanisms that are stringent enough and broad enough to actually force provinces to emit less greenhouse gas.

"The issue is going to be, how high is that price, how tough or stringent? If the regulation is not really changing anything, the implicit price is zero."

The Liberal government's political opponents are circling.

The Vancouver meeting was supposed to be the venue where a new, ambitious national target for reducing greenhouse gas emissions was set following December's international Paris climate accord.