the opposition in canada has been trying to figure this out for a while. the main opposition, the liberals, ran on a very heavily environmentally-leaning platform in 2008 and heartbreakingly lost primarily due to a split with the green party, which got almost 10% of the vote. the third party is also at least better than the ruling conservatives. the electoral system is really crippling us, and standing in the way of what popular support actually is.
there's certainly a lot of valid criticism to throw at the governing conservatives. but, to suggest that canadians are being passive on the issue is demonstrably false.