In our interconnected world, novel technology could empower just one fanatic, or some weirdo with a mindset of those who now design computer viruses, to trigger some kind of disaster. Indeed, catastrophe could arise simply from technical misadventure - error rather than terror.

The 'clean energy' challenge deserves a commitment akin to the Manhattan project or the Apollo moon landing.

The U.S., France, Germany and Canada have all responded to the financial crisis by boosting rather than cutting their science funding. The U.K. has not.

I'm not a specialist in the science but I have followed it fairly closely and it seems to me that there is among the experts a clear consensus that potential climate change is something to worry about.

Cosmology does, I think, affect the way that we perceive humanity's role in nature. One thing we've learnt from astronomy is that the future lying ahead is more prolonged than the past. Even our sun is less than halfway through its life.

The carbon dioxide concentration in the atmosphere is measured. It's uncontroversial. It's going up. We know that has a tendency to warm the atmosphere and we should be worried about that.

I'm a technological optimist in that I do believe that technology will provide solutions that will allow the world in 2050 to support 9 billion people at an acceptable standard of living. But I'm a political pessimist in that I am concerned about whether the science will be appropriately applied.