During the 20th century, we came to understand that the essence of all substances - their colour, texture, hardness and so forth - is set by their structure, on scales far smaller even than a microscope can see. Everything on Earth is made of atoms, which are, especially in living things, combined together in intricate molecular assemblages.

We need to broaden our sympathies both in space and time - and perceive ourselves as part of a long heritage, and stewards for an immense future.

Scientists habitually moan that the public doesn't understand them. But they complain too much: public ignorance isn't peculiar to science. It's sad if some citizens can't tell a proton from a protein. But it's equally sad if they're ignorant of their nation's history, can't speak a second language, or can't find Venezuela or Syria on a map.

The important point there is that when people talk about a mean temperature rise of say two, three or four degrees that's a sort of global average which really is a signature of large scale change in climatic patterns.

I think all countries need to aim to cut the CO2 emissions per person, taking account of externalities like imports and exports.

It will not be humans who watch the sun's demise, six billion years from now. Any creatures that then exist will be as different from us as we are from bacteria or amoebae.

In future, children won't perceive the stars as mere twinkling points of light: they'll learn that each is a 'Sun', orbited by planets fully as interesting as those in our Solar system.