I apologize to those of a non-scientific disposition but this is important. I'll try to make it as simple as possible.

If average global temperatures increase by more than 2°C above what they were when Watt watched his steam kettle and Abraham Darby had the bright idea of firing Coalbrookdale furnace with coke, then things will start to go seriously whoopsy. Greenland will become green and not white as it now largely is, the vast Siberian wastes will be unlocked from permafrost and start exhaling methane, and places that are now producing food will stop being productive.

To bring things a little closer to home, we'll not need to worry about corruption, noise pollution and insanely long walks at Suvarnabhumi airport because planes can't land in lakes. And Bangkok drivers will have to learn the art of driving on the Lao side of the road since the convention for shipping is to pass ‘port to port'. (And Prachatai is about to move into a ground floor office - oh dear. Where did I put my wellies?)

Now, how do we stop temperatures rising that far? Well, one of the things we will need to do is to cut emissions of carbon dioxide, the most significant of the so-called greenhouse gases (though greenhouses have got a raw deal out of this since they operate by a quite different principle).

The big question is how much do we need to cut?

This is where scientific extrapolation meets political pig-headedness. We don't exactly know. But we do know roughly and we can argue the toss till the cows swim home. But we have reached a point where we'd better do something while we argue. Just in case, like.

The Intergovernmental Panel on Climate Change, whose guesses I would put my folding money on, estimates that we might keep the increase below 2°C if, by 2050, we are producing 15% of the CO₂ we were producing in 2000. (I say ‘we', but I really mean those of you who will still be alive. I'll be a soggy mush of ash in a flooded crypt by then.)

So how much CO₂ were we producing in 2000? I'll spare you the arithmetic, but globally it works out to just over 3 and a half tonnes of CO₂ per person per year. 15% of that is a tad over half a tonne per person per year. (Maybe a bit less since there will be more per persons to go round by then.)

Good. So now we have a general idea of where we want to go. But to get there from here, we need to know where are we now.

This is the scary bit. The UNDP Human Development Report 2007-2008 gives us the figures for the 30 biggest CO₂ polluters on the planet. Thailand is up there at number 22. In 1990, Thailand was emitting 1.7 tonnes of CO₂ per capita. This is already more than 3 times the target we need to aim at.

But we've made a lot of progress since then (economic collapse or no economic collapse). By 2004, we were up to 4.2 tonnes per person.

Thailand in fact was just pipped into second place for the biggest percentage increase in per capita CO₂ emissions in the world. But no matter. We are still doing outstandingly badly and I can't think things have got better since 2004. 15 minutes of turning out (some of) the lights, just the once, doesn't really seem to be quite enough. We are going to have cut emissions by something in the region of 90%. (If it's any consolation, the US is looking at a 98% reduction.)

That's a rather big change.

So what do we do about it?

Well there's a few things we obviously don't do. We don't build more coal-fired power stations. We don't encourage more traffic by building more and bigger roads. We don't generate more flying (you can, theoretically and at some cost, de-carbonize your electricity supply and run electric cars and buses and trains, but planes can't run on batteries) so you give up on tourism as a major part of your economy.

Overall, you start looking at the prospect of doing with less. Should be easy for a nation mostly of Buddhists.

But look at what's on offer in this next election. Goodies galore. Santa Claus in suits. More of everything. Growth and more growth. Economic cancer run riot.

Sorry. Whatever we do to escape this disaster we can't rely on politics as usual. Or on business as usual, come to that.