James Lovelock:

I've been reading an interview on the Guardian's website with James Lovelock - the scientist probably best known for devising the Gaia hypothesis. While he's quite optimistic about the long term survival of the human race, he is adamant that we've missed the boat regarding reversing climate change.

...ethical consumption, carbon offsetting, recycling and so on - all of which are premised on the calculation that individual lifestyle adjustments can still save the planet. This is, Lovelock says, a deluded fantasy. Most of the things we have been told to do might make us feel better, but they won't make any difference. Global warming has passed the tipping point, and catastrophe is unstoppable.

Lovelock himself has been a long-term advocate of nuclear power, rather than renewable energy (wind, tidal), as our best way forward. That's not the problem...

Nuclear power, he argues, can solve our energy problem - the bigger challenge will be food. "Maybe they'll synthesise food. I don't know. Synthesising food is not some mad visionary idea; you can buy it in Tesco's, in the form of Quorn. It's not that good, but people buy it. You can live on it." But he fears we won't invent the necessary technologies in time, and expects "about 80%" of the world's population to be wiped out by 2100. Prophets have been foretelling Armageddon since time began, he says. "But this is the real thing."

But, to end on a positive note...

"There have been seven disasters since humans came on the earth, very similar to the one that's just about to happen. I think these events keep separating the wheat from the chaff. And eventually we'll have a human on the planet that really does understand it and can live with it properly. That's the source of my optimism."

What would Lovelock do now, I ask, if he were me? He smiles and says: "Enjoy life while you can. Because if you're lucky it's going to be 20 years before it hits the fan."