An expert panel commissioned by the BBC is meeting to debate issues raised by James Lovelock's recent book, The Revenge of Gaia.
In the publication, Professor Lovelock argues that climate change poses a major threat to the Earth's well-being, that nuclear power is the best short-term energy option, and that the size of the human population is at the root of our environmental problems.
As the panel convened, members gave their initial thoughts:
Author, The Revenge of Gaia
"We knew most of the facts, the general picture, but we never took it all that seriously. It almost seemed as if the discussion was about another planet, not the Earth, and it was academic and long-term. We realised things were far worse than we'd imagined."
Head, Climate Prediction Programme, Met Office
"I felt with my colleagues that [The Revenge of Gaia] perhaps takes the upper end of where we would expect things to happen. It's by no means outside the realms of possibility, but we felt it's perhaps not the most likely outcome."
Hans von Storch
Director, Institute for Coastal Research, Geesthacht, Germany
"This book is well meant. But climate science is a post-normal science, with high uncertainties and high stakes. And I think this book is a good example for this post-normal setup."
Professor of Environment and Policy, Cambridge University
"I don't think the global community has ever dealt with an issue on the scale of climate change. I do think it takes us into the territory of population and consumption; both issues are very difficult politically."
Director, British Antarctic Survey
"It does raise these issues... about how, collectively, we deal with something that is unprecedented; that is, how the aggregate behaviour of 6.5bn people needs somehow to be changed - how do you do that?"
Professor of Environmental Sciences, University of East Anglia
"I think that what Jim is doing here is acting as the general practitioner, the GP, for the planet, and he is saying 'look, your health is not that good... you've got to try and take this in hand'."
University Scientist; former chairman of Shell
"I think the really interesting question is that if Jim is right, ought we to be doing things very differently from the way world leaders are trying to do them today?"
Royal Society Research Professor, Reading University
"I totally agree with his analysis that we're engaged on an experiment of doing something very serious to the climate system, and the implications for our species are really quite dangerous. I hope we can turn it into a clarion call for action."
What do you think? Do you agree with James Lovelock that Earth's regulatory systems are in crisis? Should we switch to nuclear fission? Send us your questions on the human impact on the climate now.
Conclusions of the BBC panel will be reported on Thursday on Radio 4's Today programme and on the BBC News website