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.

In the case of climate change, the threat is long-term and diffuse and requires broad international action for the benefit of people decades in the future. And in politics, the urgent always trumps the important, and that is what makes it a very difficult and challenging issue.

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.

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

I hope that by 2050 the entire solar system will have been explored and mapped by flotillas of tiny robotic craft.

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.

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.