One of the questions that came up lately in my dialogue with commentators is that of the reversibility of major ecological disasters induced by human activity and of the feasibility of reversing such disasters with the tools pertaining to our current technology.

This is a serious question, a very serious one, and I intend to use the popularity of my (French) blog to push the issue a far as needs be. I’ve chosen one example – so that we don’t get locked in trivial generalities – that of a possible interruption of the Gulf Stream due to human activity. The consensus is that such an interruption – which I understand already occurred for ten days in 2004 – would make the temperature in Western Europe drop permanently by 5 to 10 degrees Celsius, that is, 10 to 20 degrees Fahrenheit. Is the interruption a possibility – even remote – and should the event occur, what are our realistic chances of reversing it?

Well, that's a good question. Damned if I know the answer.