Martin Rees is Astronomer Royal, former President of the Royal Society, Fellow (and former Master) of Trinity College, Cambridge, and Emeritus Professor of Cosmology and Astrophysics at the University of Cambridge. He sits as a member of the UK House of Lords.

Tim Radford joined the New Zealand Herald as a reporter aged sixteen and moved to the UK in 1961. He is a freelance journalist and a founding editor of Climate News Network. He worked for the Guardian for thirty-two years, becoming - among other things - letters editor, arts editor, literary editor and science editor.

He won the Association of British Science Writers award for science writer of the year four times and a lifetime achievement award in 2005. He is an honorary Fellow of the British Science Association, and a Fellow of the Royal Geographical Society. He is the author of The Crisis of Life on Earth: Our Legacy from the Second Millennium and The Address Book: Our Place in the Scheme of Things.

Edward O. Wilson is widely recognized as one of the world's pre-eminent biologists and naturalists. The author of more than twenty books, including Consilience, The Diversity of Life, The Social Conquest of Earth, The Meaning of Human Existence and Letters to a Young Scientist, Wilson is a Professor Emeritus at Harvard University. The winner of two Pulitzer Prizes, he lives in Lexington, Massachusetts.

Oliver Morton is a senior editor at The Economist and an award winning writer. He is the author of Mapping Mars: Science, Imagination and the Birth of a World, Eating the Sun: How Plants Power the Planet and The Planet Remade: How Geoengineering Could Change the World.

John Gray's most recent book is the highly praised Seven Types of Atheism; his other books include Straw Dogs, Black Mass, The Soul of the Marionette and The Silence of Animals. He has kept feline companions for over thirty years.

The Times described Fred Pearce recently as one of Britain's finest science writers. An author and journalist based in London, he has reported on environment, popular science and development issues from over 60 countries over the past 20 years, specialising in global environment issues. He is the environment and development consultant for the New Scientist and writes regularly for the Daily Telegraph, the Guardian, the Independent the Times Higher Education Supplement and Country Life.

In the US he has written for the Boston Globe, Audubon Magazine, Foreign Policy, Seed, Popular Science and Time and has written reports and extended journalism for WWF, the UN Environment Programme, the Red Cross, UNESCO, the World Bank and the UK Environment Agency. He is syndicated in Japan, Australia and elsewhere and his books have been translated into at least ten languages, including French, German, Portuguese, Japanese and Spanish.

He was voted BEMA Environment Journalist of the Year in 2001 and has been short-listed for the same award in 2000, 2002 and 2003. He is a past recipient of the Peter Kent Conservation Book Award and the TES Junior Information Book Award.

He is a regular broadcaster on radio and TV, and has given public lectures on all six continents in the past two years.

James Lovelock is an independent scientist, environmentalist, and originator of the Gaia theory which considers the Earth a living and evolving system striving to regulate itself so that contemporary life can flourish.

Lovelock has been cited as one of the world’s top 100 intellectuals (Prospect), “a scientific visionary” (The Times), and “one of the greatest thinkers of our time” (New Scientist).