Canadian Press: A new poll suggests most Canadians support the idea of a carbon tax – but an overwhelming majority favour the broader principle of using the tax system to punish or reward environmental behaviour. The findings of The Canadian Press Harris-Decima survey suggest the politically risky move of putting a price on carbon holds a potential payoff. The federal Liberals are weighing a plank in their platform that would put a price on pollution – and Environment Minister John Baird …