The 20th anniversary of Chernobyl is for me a chilling reminder of human folly and the difficulty we have, even now, of recognising and owning up to it.

Two memories of the Chernobyl aftermath have burned themselves into my brain: a few day's after hearing about the incident that had occurred more than 1000 miles away to the east, I was thinking of going for a walk, when I noticed that it looked a bit like rain. Normally I enjoy walking in the rain, but now, with clouds of radioactivity waiting to be washed out of the atmosphere, it didn't seem like such a good idea.  At about the same time I noticed spray-written on a wall:

"My God, it's raining!" The most chilling thing I have ever read . . .

Techno-arrogant man had succeeded in transforming rain, the welcome bringer of life, over an entire continent, into a feared, possible bringer of death and pain.