Do politicians understand just how difficult it could be, just how devastating rises of 4C, 5C or 6C could be? I think, not yet

Meat is a wasteful use of water and creates a lot of greenhouse gases. It puts enormous pressure on the world's resources. A vegetarian diet is better.

We can look back through ice-core data and see over 800,000 years, relationships between carbon dioxide and the temperature of the world. So those people who deny the importance of climate change are just wasting their time. They're also being diversionary because if we don't act the risks are enormous.

Climate change and global poverty are two sides of the same coin. Both challenges must be addressed together. If we fail on one, we will also fail on the other.

Climate change is a result of the greatest market failure the world has seen...We risk damages on a scale larger than the two world wars of the last century.

It's very important that there should be cross-fertilisation between government and academia. Both parties can benefit from having a better understanding of how the other works.

Climate change will affect the basic elements of life for people around the world - access to water, food production, health, and the environment. Hundreds of millions of people could suffer hunger, water shortages and coastal flooding as the world warms.