TORONTO - Canada's environment ministers are meeting today in Ottawa to discuss reducing greenhouses gases but how that will be accomplished is leaving some premiers wary.

Ontario's Dalton McGuinty says that a national cap-and-trade system cannot "discriminate" against his province and any gains generated by the province must remain there.

That got Premier Ed Stelmach upset, saying Alberta has already put a price on carbon emissions.

He says he doesn't want to see another premier imposing a policy across Canada that might put additional costs on Albertans.

Quebec is calling for Ottawa to raise its targets for cutting greenhouse emissions.

Cap-and-trade systems place a ceiling on greenhouse gases and let participants buy and sell emissions permits within that cap.

Those who don't meet the emissions targets can buy credits from others with a surplus instead of lowering their emissions.