In an extended conversation, Philip Dodd talks to pioneering scientist James Lovelock - originator of the concept of Gaia - about his remarkable life and the future of our planet.
Lovelock's life in science has spanned some of the most advanced changes of the 20th century. He worked for Nasa on the Mars projects at one of its most exciting periods in the 1960s and it was during this time he developed his famous Gaia Hypothesis - now Gaia Theory - that the Earth functions as a living, self-regulating super-organism.
But the man and his theory continue to divide scientists and environmentalists. Despite everything that he has done for raising the danger of global warming, Lovelock restates his view that much of the Green movement lags far behind science. Environmentalists, in turn, are hostile to his support for nuclear power as an interim solution to the world's energy problems.
Philip asks Lovelock why he has spent so much of his life as an independent scientist, living and working at his rural home in Cornwall, and asks him to stand by his prediction that much of humanity could perish as a result of global warming by the end of this century.