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.

One of the computer models for a four degree temperature rise would give rise to a 10 degree temperature rise in Africa. And bear in mind also that in the depth of an ice age the mean temperature drop compared to the present was five degrees.

There may be organic life out there, or maybe machines created by long-dead civilizations, but any signals, even if they are difficult to decode, would tell us that the concepts of logic and physics are not limited to the hardware in human skulls, and will transform our view of the universe.

It used to be controversial whether smoking caused lung cancer, it used to be controversial whether HIV caused AIDS. Now, there are a few mavericks who deny those things. In the case of climate change, I think the debate is going the same way in that there is a strong consensus that it is a serious matter.

If we ever establish contact with intelligent aliens living on a planet around a distant star ... They would be made of similar atoms to us. They could trace their origins back to the big bang 13.7 billion years ago, and they would share with us the universe's future. However, the surest common culture would be mathematics.

I suspect there could be life and intelligence out there in forms we can't conceive. Just as a chimpanzee can't understand quantum theory, it could be there as aspects of reality that are beyond the capacity of our brains They could be staring us in the face and we just Don't recognise them. The problem is that we-re looking for something very much like us, assuming that they at least have something like the same mathematics and technology.

I think a few hundred years from now we'll start having the 'posthuman' era of different species.