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

James Lovelock, the British environmental scientist whose influential Gaia theory sees the Earth as a living organisms gravely jeopardized by human activity, has died at the age of 103.

The family of Lovelock said that he died at his home in southwest England on Tuesday. After a bad fall, Lovelock's health deteriorated but he was still able to walk along the coast and take part in interviews.

Lovelock studied medicine and chemistry in the U.K. and the U.S. when he was a child.

He was employed at the National Institute for Medical Research in London. He looked at the effect of temperature on living organisms in some of his experiments. The animals are still alive.

Lovelock worked for NASA on the moon and Mars programs. He was an independent scientist for most of his career.

A highly sensitive electron capture detector was developed by Lovelock to measure ozone-depleting chlorofluorocarbons in the atmosphere.

The Earth was thought to be a self-regulating system that created and maintained the conditions for life on the planet. The scientists said that human activity had thrown the system off--

Lovelock used books, speeches and interviews to warn of the consequences of climate change.

Lovelock told The Guardian that he and the biosphere were both in the last 1%.

The Gaia theory became influential because of its power as a metaphor and because it was dismissed by many scientists. The Greek goddess of the earth is named Gaia.

Being an outsider didn't bother Lovelock. Nuclear energy was the only way to stop global warming according to him.

He said that the opposition to nuclear energy was based on irrational fear. Nuclear energy has proved to be the safest of all energy sources.

Lovelock proposed in his last book that humans will be replaced by machines.

The Green movement has lost a huge champion and intellect, according to Britain's only Green lawmaker.

Roger Highfield, science director at Britain's Science Museum, said that Lovelock was a nonconformist who had a unique vantage point that came from being.

"Endless ideas bubbled forth from this synergy between making and thinking, from freezing hamsters to detecting life on Mars," Highfield said.

Lovelock is survived by his family.

They said that he was best known as a scientific pioneer and climate prophet. He was a loving husband and father with a passion for nature and a mischievous sense of humor.

There will be a private funeral and a public memorial service.