Enlightened self-interest from those involved in hydrocarbons should lead to the support of technologies enabling the clean use of hydrocarbons, such as carbon capture and storage, and not to the defence of deniers and cranks.

What we are talking about is extended world war...People would move on a massive scale. Hundreds of millions, probably billions of people would have to move.

As an undergraduate, I did maths and physics. That doesn't make me a scientist. So I try to read and understand and talk to scientists.

There is still time to avoid the worst impacts of climate change, if we take strong action now.

Unfortunately, the current pace of progress is not nearly rapid enough, with many rich industrialised countries being slow to make the transition to cleaner and more efficient forms of economic growth.

If coal is going to be used, the only response - because it is the dirtiest of all fuels - is that we have to learn how to do carbon capture and storage and we have to learn how to do it quickly on a commercial scale.

How is it that, in the face of overwhelming scientific evidence, there are still some who would deny the dangers of climate change? Not surprisingly, the loudest voices are not scientific, and it is remarkable how many economists, lawyers, journalists and politicians set themselves up as experts on the science.