More than five years ago I linked to an argument by Canadian conservative newspaper columnist Andrew Coyne favouring action on climate change. His argument, essentially, was that:
...the chances that the many distinguished scientists who predict an impending climatological catastrophe will prove to be right must be considerably greater than the chances I will be run over by a bus tomorrow. Or at any rate, they are greater than zero. In which case, would it not be prudent to take out some insurance against the event?
And that the costs of emissions reductions and alternative energy strategies are not (or at least, were not in 2002) out of line with what you would expect to pay for insurance on similar potential risks.
My cousin recently sent me a simple nine-minute YouTube video on climate change risks (not really the "most terrifying video you'll ever see," but hey). It makes a similar point, perhaps more clearly, or at least more visually, with nothing but a guy at a whiteboard:
It comes down to choices vs. guesses: we can choose to change our energy use and effects on the planet's climate, or we can guess that we don't really need to do that. The risk of guessing is much bigger than the risk of choosing.