Stephen Harper and company have spent the past week trying to convince us all that they are the ones truly committed to doing something on Kyoto. One tactic has been to trash the previous Liberal record on global warming.
Fair enough, the Liberals do deserve criticism for their lax record. The catch is that governments don't respond to these things in a vacuum. They take into account response to their plans on the part of individuals, corporations, lobby groups, provinces AND the official opposition. During the late nineties after the Liberals had signed Kyoto, but did not then move quickly to take the steps necessary to achieve the goals. Across the House of Commons they faced a Canadian Alliance opposition which vigourously attacked them, for example, for considering mandatory greenhouse gas emission caps (Alliance MP Dave Chatters speech in 1997 on this subject illustrated the attitude).
Now, if the Canadian Alliance had been attacking the Liberals for not moving fast enough on meeting Kyoto targets, that could have made a significant difference to the behaviour of the Chrétien government. Paul Martin's February, 2000 budget was filled with various tax cuts (even using the neocon phrase "tax relief" to describe them) in order to undercut the campaign by the Alliance for tax cuts as a way of spending the then growing surplus.
Listening to them suggest they will do now what the Liberals failed to do then is a bit much, as it ignores their own very considerable political responsibility for that record.