If something bad happens, people who had warned that it was likely often say, "I don't like to say it, but, I told you so!"

Why is it that one is supposed not to like to say it?

Is it perhaps that we don't like to admit it when we were wrong, especially when we were warned that we were wrong? Are people who make us realise that we made a predictable - almost wilful - mistake unwelcomed because of that fact?

The honest truth is that we ought to listen to those who told us so. They saw it coming – they will be better at heading it off, next time.

Some people think the rhetoric of climate change is too emotive. But faced with a global catastrophe it would be unwise to tone down our language.

We are all familiar by now with the shrill voices of climate change deniers. But with every passing week they become more and more irrelevant, as their 'scepticism' about the reality of man-made climate change is exposed as risible. The issue now is not whether we are certain that dangerous climate change is real and is happening - the issue is only how we are going to tackle it. So how do we motivate people to act? How do we persuade them not to seek refuge in psychological defence mechanisms of the kind Leo Hickman chronicled in the Guardian last week?