The Gaia hypothesis states that the Earth's atmosphere and surface sediments are actively maintained by interactions between biota, surface sediments and the air.
First proposed by James Lovelock, and developed with Lynn Margulis in the 1970s, Gaia brings together Earth and life scientists, and was the subject of 'Life and the Planet', a conference held at the Geological Society in May 2011. Here, through interviews and audio recordings from the conference, James Lovelock and Lynn Margulis look back to the early days of the Gaia hypothesis, its reception and how it can help scientists and the public to understand the challenges faced by the Earth today.