James Lovelock, who theorized that Earth is a living organism, dies at 103

Scientist and inventor James Lovelock poses with one of his early inventions, a homemade gas chromatography device, used for measuring gas and molecules present in the atmosphere, at a science museum in London. (Nicholas.T.Ansell/PA via AP, file)

LONDON — James Lovelock, the British environmental scientist whose influential Gaia theory sees the Earth as a living organism gravely imperiled by human activity, has died on his 103rd birthday.

Lovelock's family said Wednesday that he died the previous evening at his home in southwest England "surrounded by his family." The family said his health had deteriorated after a bad fall but that until six months ago Lovelock "was still able to walk along the coast near his home in Dorset and take part in interviews."