Climate change should be seen as the greatest challenge to face man and treated as a much bigger priority in the United Kingdom.

I believe passionately that everyone has a particular God-given ability.

Forests ... are in fact the world's air-conditioning system-the very lungs of the planet-and help to store the largest body of freshwater on the planet ... essential to produce food for our planet's growing population. The rainforests of the world also provide the livelihoods of more than a billion of the poorest people on this Earth... In simple terms, the rainforests, which encircle the world, are our very life-support system-and we are on the verge of switching it off.

One of the main reasons for the conflict in Syria, and the terrorism that it's spawned, is climate change and drought.

If you think about the impact of climate change, [it should be how] a doctor would deal with the problem. A scientific hypothesis is tested to absolute destruction, but medicine can't wait. If a doctor sees a child with a fever, he can't wait for [endless] tests. He has to act on what is there. The risk of delay is so enormous that we can't wait until we are absolutely sure the patient is dying.

The whole imposing edifice of modern medicine is like the celebrated tower of Pisa - slightly off balance.

The sustainability revolution will, hopefully, be the third major social and economic turning point in human history, following the Neolithic Revolution - moving from hunter-gathering to farming - and the Industrial Revolution