In 1979, James Lovelock’s book Gaia:
A New Look at Life on Earth, rattled the scientific world and electrified
the rest of us by arguing that the Earth behaves like a single living
organism that creates and maintains a viable environment for life. The Gaia
hypothesis offered a coherent vision of the whole living world that echoed
all our wisdom traditions and renewed the human sense of wonder.
Silver Donald Cameron
Lovelock’s bold insights became the
foundations of Earth-systems science, the study of systems like the
circulation of the oceans, the maintenance of the atmosphere, and the
relationships among the Earth’s biological and geological processes. He has
been called the most important figure in the life sciences and the climate
sciences for the past half century, and his stature has been compared to
Darwin’s. Here is part of an interview I conducted with him in January,
You said at one point that the germ
of the Gaia theory was your realization that the Earth had “an atmosphere
that was wildly anomalous, and a strange, wonderful and beautiful anomaly
that sort of shouted a song of life right across the solar system, right out
into the galaxy.” I want to take you right back to that beginning of when
you began to suspect that the Earth as a whole could be seen as an organism.
Tell me how that came about.
Well, it came about when I was
working for NASA. They were then – and I’m talking about 1965 – just as now,
obsessed with finding life on Mars. I put forward a paper in Nature
suggesting that they were going about it the wrong way [by] sending
biological expeditions there to look for microbes and things. The only way
to look for life on Mars was to check if the planet had a lower entropy than
the other planets, following Schrödinger, the great physicist’s idea. They
naturally asked, “Well, how on earth would you measure entropy?” After a lot
of thought it occurred to me that all you have to do is measure the chemical
composition of the atmosphere. If it’s way out of equilibrium chemically,
then it has a low entropy. If there’s life on the planet, it will be bound
to use the atmosphere for raw materials and a place to dump waste, just as
we do. That tells you whether there is life there.
One afternoon at Jet Propulsion Lab,
I was in a room with Carl Sagan and a colleague of mine, Dian Hitchcock. In
marched an astronomer, Lew Kaplan, and he said, “Look at this!” He brought
great sheets of data. He said, “Here are the complete analyses of the
chemical compositions of Mars and Venus.” We said, “Well, what is it?” He
said, “They’re both almost entirely carbon dioxide with just traces of the
other gases present.” And I knew instantly that they were both
chemical-equilibrium atmospheres, just what you’d expect. Then I suddenly
thought, “But the Earth is so weird.” [Here] you’ve got oxygen in abundance
mixed with hydrocarbons like methane. So something must be producing the
pair of them – and in substantial quantity. There’s only one thing that
could make them, and that was life.
Of course, it was wrong. There’s
just no way for living organisms to regulate anything beyond their
phenotypes, so how could they be regulating the planet?
This forced me to rethink. It took
me about a year and it suddenly dawned on me that it wasn’t the life that
was regulating the planet. It was the whole damn system of life and the
environment tightly coupled as a single entity. Of course, this didn’t cut
any ice with the critics, so what I did was make a simple mathematical
That would be the Daisyworld model?
Yes. It showed how a planet with two
competing species of dark- and light-colored daisies could regulate its
surface temperature with extraordinary accuracy and home in automatically on
the most favorable temperature for daisy growth. It was about as solid as it
could be. It was a model that you could kick. What happens if a plague kills
off seventy percent of the daisies? Does it still regulate? Yes, it does.
You continue to be a bit of a critic
of science too, particularly at the moment – a critic of climate science and
the way that it’s proceeding. You argue that the situation may be much worse
than the traditional mainstream climate scientists say it is.
That’s right. Well, you see, if you
look at the history of the Earth, you find that it seems, as far as climate
goes, to have two main stable states. One is about five or six degrees
hotter than now and the other five or six degrees colder than now. And once
in those states, it can stay there for long periods of time fairly stably…So
we are poised between slipping back into glaciation and moving to a hot
If we go on adding greenhouse gases
and nothing else, we will almost certainly precipitate a flip to the hot
state because once we’ve added a certain amount and the Earth has warmed up
a bit, then the whole system starts emitting carbon dioxide at a
Now think of the permafrost in
Canada and Siberia. It will soon be releasing methane and carbon dioxide in
huge amounts, and that’s the sort of process that will cause the jump up to
the hot state. It’s only one of five total positive feedback systems like
that, and several of them involve the ocean. So it’s a complex process, but
a whole system process, and you can see where it will go.
To see this full one-hour interview (in video, audio or
transcript), go to
www.TheGreenInterview.com and sign up for a free one-week subscription.
The site offers more than sixty in-depth interviews with environmental
giants from around the world. Silver Donald Cameron, host and executive
producer at The Green Interview, is one of Canada’s most respected authors
and broadcasters. The Living Beach, his classic book on the ecology of
shorelines, has just been re-issued by Red Deer Press.
This article was published in Natural Life Magazine in 2014.