I think it's important for scientists to be a bit less arrogant, a bit more humble, recognising we are capable of making mistakes and being fallacious - which is increasingly serious in a society where our work may have unpredictable consequences.

The trouble with climate change is it's an extraordinarily diverse and complex issue, but for example if the BBC would let me make some of the programmes I'd like to make on climate change, I bet you there would be a change of emphasis.

I don't know whether it is important to study science at a young age, though current thinking emphasises the need.

Carbon dioxide is unusual because it doesn't go through the usual three phases of matter, from solid to liquid to gas, but it goes straight from solid to gas. The volume of the gas is much greater than the volume of the solid. When a solid turns into a gas, we say it sublimes. The process is sublimation.

Nearly all inventions are not recognised for their positive side either when they're made. So, for example, scientists didn't go out to design a CD machine: they designed a laser. But we got all sorts of things from a laser which we never remotely imagined, and we're still finding things for a laser to do.

Following 25 children for the TV series 'Child of Our Time' has been extraordinary. The BBC's original plan was to commemorate the new millennium. What better way than to film a number of expectant mums from across the U.K.? Coming from widely different backgrounds, all were due to give birth on January 1, 2000.

The disturbed individual who believes himself to be Christ, or to receive messages from God, is something of a cliche in our society. Ever since Sigmund Freud, many people have associated religiosity with neurosis and mental illness.