“Computer models used to forecast climate decades from now are based on the same fundamentals as models used to predict next week’s weather.

No sensible person would bet on a seven-day weather forecast so why should Canada wager billions on what the models predict for a century from now?”

This quote, from an opinion page submission written by Tom Harris and Tim Ball, has a tempting ring of truth to it. (Stephen Colbert calls it “truthiness:” something that may not actually be correct but which nevertheless feels right.) Still, the statement is silly.

Our understanding of climate, as opposed to weather, is based largely on statistical probability – on making sound assumptions based on known data. It’s true, for example, that the weather office can’t give you an iron clad forecast seven days in advance, but given that it’s January in Vancouver, any idiot could tell you that it will probably be raining.

Where climate change is concerned, though, we don’t have to rely on “any idiot” – or even on highly respected skiers and business people who haven’t got a clue about climate science. At the end of the month, the best climate scientists in the world – contributors to the Intergovernmental Panel on Climate Change – will come out with their latest assessment. And regardless of what industry apologists like Tom Harris and Tim Ball want that report to say, advance copies suggest it will be more conclusive than ever: humans are causing the climate to change in a way and at a speed that is unprecedented in tens of thousands and perhaps hundreds of thousands of years.

You don’t have to be a climate scientist to understand that reality, but if you have to take someone’s word for it, make sure it’s someone who a) knows what they’re talking about and b) is willing to tell you who is paying them to lobby against climate change regulations. (Which is to say, neither Tim Ball nor Tom Harris.)