It’s always good politics to blame your predecessors in government for their mistakes, but Conservative Environment Minister Rona Ambrose is finding that tactic can be risky when you get caught making the mistakes up.

According to this Canadian Press story, Ambrose had to apologize yesterday for saying that the Liberal government had spent “at least $100 million” in foreign carbon credits. The real number was, well, zero.

And to think she’s in charge of setting new policy on an issue that may be critical not just to Canada’s international reputation, but also to the future state of the world.