Martin Rees

One of President Obama's first acts was to give a massive boost to America's scientific community.

Campaigning against religion can be socially counter-productive. If teachers take the uncompromising line that God and Darwinism are irreconcilable, many young people raised in a faith-based culture will stick with their religion and be lost to science.

I've got no religious beliefs at all.

I have no religious belief myself, but I don't think we should fight about it. In particular, I think that we should not rubbish moderate religious leaders like the Archbishop of Canterbury because I think we all agree that extreme fundamentalism is a threat, and we need all the allies we can muster against it.

I'm not myself religious but have no wish to insult or denigrate those who are.

Devastation could arise insidiously, rather than suddenly, through unsustainable pressure on energy supplies, food, water and other natural resources. Indeed, these pressures are the prime 'threats without enemies' that confront us.

Over most of history, threats have come from nature - disease, earthquakes, floods, and so forth. But the worst now come from us. We've entered a geological era called the anthropocene. This started, perhaps, with the invention of thermonuclear weapons.

It might seem paradoxical that the biggest scientific instruments of all are needed in order to probe the very smallest things in nature. The micro-world is inherently 'fuzzy' - the sharper the detail we wish to study, the higher the energy that is required and the bigger the accelerator that is needed.

Space and time may have a structure as intricate as the fauna of a rich ecosystem, but on a scale far larger than the horizon of our observations.

The scientific community should work as hard as possible to address major issues that affect our everyday lives such as climate change, infectious diseases and counterterrorism; in particular, 'clean energy' research deserves far higher priority. And science and technology are the prime routes to tackling these issues.

Some global hazards are insidious. They stem from pressure on energy supplies, food, water and other natural resources. And they will be aggravated as the population rises to a projected nine billion by mid-century, and by the effects of climate change. An 'ecological shock' could irreversibly degrade our environment.

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.