Professor Ross Garnaut this afternoon released an interim report as part of the still unfolding Garnaut Climate Change Review. The shorthand message: This Is Serious Folks.

As Professor Garnaut puts it:

There are considerable uncertainties attached to both climate change impacts and mitigation. Many would argue that the uncertainty requires a conservative rather than ambitious approach to mitigation. But what is conservative in a context where the possible outcomes include some that most humans today would consider catastrophic?

Conservatism may in fact require erring on the side of ambitious mitigation. After all, prudent risk management would suggest that it is worth the sacrifice of a significant amount of current income to avoid a small chance of a catastrophic outcome.

Oh dear. Hang on to your hats people.