Elevated on its embankment, our train trundled through the floods. Water as far as the eye could see: it felt as though we were travelling on Noah’s ark. And still it rained. Britain, it seemed, had been turned into a vast lake. In the distance, white flashes showed where wild swans gathered on the few hillock islands. A distant cathedral rose like a sea cliff. Britain is a wet country, but we all know that biblical deluges like this are not normal; yet, as climate change grips, they are fast becoming the norm.