Politicians fighting the federal carbon tax say action is needed on climate change, but remedies should be left to the provinces.

"Climate change is caused by human activities and is a serious threat … but it is a challenge that the provinces are equipped to deal with," Saskatchewan Attorney General Don Morgan said following a meeting Tuesday in Saskatoon.

The meeting included the attorneys general of Saskatchewan, Alberta, Ontario and New Brunswick, who made a public statement Tuesday afternoon about their upcoming hearing at the Supreme Court of Canada.

Morgan said the cost of the legal challenges will run in the "hundreds of thousands" of dollars in Saskatchewan alone.

'The climate is changing, why aren't we?' read one of the signs held by a student at a rally for the environment in Regina. (CBC News/Radio Canada )

Under the federal government's pan-Canadian climate framework, all provinces are required to come up with a method to price carbon in order to reduce climate-altering carbon emissions.

On May 3, the Saskatchewan Court of Appeal ruled in a 3-2 decision that the federal government's carbon tax, imposed on provinces deemed not to have sufficient plans of their own, is constitutional.

Saskatchewan and then Ontario launched appeals to the Supreme Court. Alberta, Ontario and New Brunswick have registered as interveners in the Saskatchewan challenge.

"This is mission-critical, it's the future of our province," Alberta Attorney General Doug Schweitzer said of the court fight.

It's unclear whether the provinces will make any new points.

Ontario Attorney General Doug Downey said they plan to put forward a "vigorous" argument to the Supreme Court Dec. 5.

New Brunswick Attorney General Andrea Anderson-Mason said her province reduced emissions on its own by more than a quarter, and should be allowed to continue without federal intervention.

Carbon pricing essential, environmentalist says

However, one environmentalist said carbon pricing is exactly what these provinces need.

"Market prices influence people's behaviour. It seems like an eminently sensible way of approaching the greenhouse gas problem," Saskatchewan Environmental Society board member Ann Coxworth said.

Saskatchewan Environmental Society board member Ann Coxworth says carbon pricing is an effective way to curb emissions.

Coxworth said carbon pricing has been shown to reduce emissions in other jurisdictions, so it's reasonable to expect it would be successful in places such as Saskatchewan.

She said it's essential to act now, especially in Saskatchewan where per capita emissions are extremely high.

"The increase in greenhouse gases is causing climate disruption, so we have to do our share," Coxworth said.