Mark Lynas’s Copenhagen Notebook: 12/12/2009

*It's easy to mock the proceedings here. Upwards of 25,000 people, most of whom came by plane, meeting to write convoluted UN legalese that no one understands and doesn't seem to ever change anything.

But I think if you were an alien looking in you might take this meeting as evidence of humans behaving like an intelligent species. We've used rational, objective analysis – otherwise known as science – to establish beyond reasonable doubt that we have a problem which threatens the habitability of our world, and here we have representatives from all corners of human civilisation meeting together to try to do something about it. They may not succeed, but actually witnessing this gargantuan effort – and the passion and commitment of so many of those here, government delegates as well as seasoned campaigners – is actually rather wonderful.

*The first week has been nothing if not turbulent. Conference proceedings are still suspended as countries battle it out behind closed doors about the way ahead. Yet none of the cynics seem to mention that there is still language in some of the negotiating texts that would – if agreed on by all parties – largely solve the problem of global warming. Two numbers are crucial here: 1.5 and 350.

*1.5 refers to the rise in Centigrade above preindustrial levels (we've already seen 0.7C) which is the maximum tolerable for ecosystems and much of human civilisation. The Maldivians (who I am joining this year as a delegate) have a slogan for it: "1.5 to stay alive". Any more would put their nation under water. The second figure refers to the mark that CO2 levels must return to in order to get Earth back into the zone of relative safety, identified by a growing number of scientists as 350 parts per million (we're currently at 387).

*Getting back to 350 would keep the polar ice caps largely intact, ensure that the Himalayan glaciers don't melt away, constrain sea-level rise to tolerable limits and stop the world's tropical coral reefs from going extinct. Both 1.5 and 350 are still in the draft texts at the end of the first week – but in square brackets. That they haven't disappeared is largely thanks to the efforts of Tuvalu, which is gathering a coalition of other island states, African countries and developing nations. So long as their voices are heard, we are in with a chance.

Mark Lynas, one of Britain's leading climate change experts and author of 'Six Degrees', the Royal Society's Science Book of the Year, will be writing for 'The Independent' throughout the final stages of the Copenhagen negotiations. He is attending the conference as an adviser to the Maldives.