Lovelock, born in 1919, is best known for the ‘Gaia hypothesis’, which proposes that the Earth functions as a self-regulating system, similar to a living organism. The idea sparked controversy when Lovelock and microbiologist Lynn Margulis proposed it in the 1970s, but environmental and Earth scientists now accept many of its basic principles. In 2006, his book The Revenge of Gaia predicted disastrous effects from climate change within just a few decades, writing that  “only a handful of the teeming billions now alive will survive”.