ALLIGATORS basking off the English coast; a vast Brazilian desert; the mythical lost cities of Saigon, New Orleans, Venice and Mumbai; and 90 per cent of humanity vanished. Welcome to the world warmed by 4 degrees C.

Clearly this is a vision of the future that no one wants, but it might happen.

That’s the start of an article in New Scientist that I read two months ago that has haunted me most days since (see the map better here, but you have to subscribe). I have read a fair amount about global warming, in a lay person’s sort of way, but when I read that James Lovelock, the Gaia Hypothesis guy, said that most of humanity would be gone by the end of the century I thought he was just an old man going a bit off his rocker.

I was also so deeply affected by doom scenarios in my twenties, none of which turned out to materialize, that I had become skeptical of new ones. I got interested in how attracted we are to apocalyptic fears–there is so much history of that, especially in European culture and its American diaspora. Plus it seemed to me that the Left had discounted the adaptability of markets and that explained the mistake of the late 1960s doomsters (like the Ehrlichs and the Club of Rome), who said there would be more shortages of everything, from food to metals, when in actuality we had less famine and cheaper raw materials in the subsequent decades (as famously argued by Julian Simon). So I preached about the return of hope (still available here on my frozen-in-time website that I haven’t done a thing to since starting at Tikkun). I didn’t discount global warming, but I didn’t think it would be anything like this bad.

But this article was like some sort of straw on this camel’s back. The idea that there may only be one billion of us left at the end of century is haunting me. My wife and I will be long gone, but our son, now 20, can expect to live through a lot of it, and should I be hoping for grandchildren or not?