A frequent misunderstanding of my vision of Gaia is that I champion complacence, that I claim feedback will always protect the environment from any serious harm that humans might do. It is sometimes more crudely put as “Lovelock’s Gaia gives industry the green light to pollute at will.” The truth is almost diametrically opposite. Gaia, as I see her, is no doting mother tolerant of misdemeanors, nor is she some fragile and delicate damsel in danger from brutal mankind. She is stern and tough, always keeping the world warm and comfortable for those who obey the rules, but ruthless in her destruction of those who transgress. Her unconscious goal is a planet fit for life. If humans stand in the way of this, we shall be eliminated with as little pity as would be shown by the micro-brain of an intercontinental ballistic nuclear missile in full flight to its target.

Contact means the exchange of specific knowledge, ideas, or at least of findings, definite facts. But what if no exchange is possible? If an elephant is not a giant microbe, the ocean is not a giant brain.

Edna St Vincent Millay said:
My candle burns at both ends;
It will not last the night;
But, ah, my foes, and oh, my friends –
It gives a lovely light.
So it is with Gaia. The first aeons of her life were bacterial, and only in her equivalent of late middle age did the first meta-fauna and meta-zoa appear. Not until her eighties did the first intelligent animal appear on the planet. Whatever our faults, we surely have enlightened Gaia’s seniority by letting her see herself from space as a whole planet while she was still beautiful.

Gaia is a thin spherical shell of matter that surrounds the incandescent interior; it begins where the crustal rocks meet the magma of the Earth’s hot interior, about 100 miles below the surface, and proceeds another 100 miles outwards through the ocean and air to the even hotter thermosphere at the edge of space. It includes the biosphere and is a dynamic physiological system that has kept our planet fit for life for over three billion years. I call Gaia a physiological system because it appears to have the unconscious goal of regulating the climate and the chemistry at a comfortable state for life. Its goals are not set points but adjustable for whatever is the current environment and adaptable to whatever forms of life it carries.

I know that to personalize the Earth System as Gaia, as I have often done and continue to do in this book, irritates the scientifically correct, but I am unrepentant because metaphors are more than ever needed for a widespread comprehension of the true nature of the Earth and an understanding of the lethal dangers that lie ahead.

I recognize that to view the Earth as if it were alive is just a convenient, but different, way of organizing the facts of the Earth. I am, of course, prejudiced in favour of Gaia and have filled my life for the past 25 years with the thought that the Earth might be in certain ways be alive—not as the ancients saw her, a sentient goddess with purpose and foresight—more like a tree. A tree that exists, never moving except to sway in the wind, yet endlessly conversing with the sunlight and the soil. Using sunlight and water and nutrients to grow and change. But all done so imperceptibly that, to me, the old oak tree on the green is the same as it was when I was a child.

No one who has experienced the intense involvement of computer modeling would deny that the temptation exists to use any data input that will enable one to continue playing what is perhaps the ultimate game of solitaire.

The Earth has recovered after fevers like this, and there are no grounds for thinking that what we are doing will destroy Gaia, but if we continue business as usual, our species may never again enjoy the lush and verdant world we had only a hundred years ago. What is most in danger is civilization; humans are tough enough for breeding pairs to survive, and Gaia is toughest of all. What we are doing weakens her but is unlikely to destroy her. She has survived numerous catastrophes in her three billion years or more of life.

The Gaia Hypothesis asserts that Earth’s atmosphere is continually interacting with geology (the lithosphere). Earth’s cycling waters (the hydrosphere), and everything that lives (the biosphere). … The image is that the atmosphere is a circulatory system for life’s bio-chemical interplay. If the atmosphere is pan of a larger whole that has some of the qualities of an organism, one of those qualities we must now pray for is resilience.

The idea that the Earth is alive may be as old as humankind. The ancient Greeks gave her the powerful name Gaia and looked on her as a goddess.

Unfortunately, we are a species with schizoid tendencies, and like an old lady who has to share her house with a growing and destructive group of teenagers, Gaia grows angry, and if they do not mend their ways she will evict them.

Until that afternoon, my thoughts on planetary atmospheres had been wholly concerned with atmospheric analysis as a method of life detection and nothing more. Now that I knew the composition of the Martian atmosphere was so different from that of our own, my mind filled with wonderings about the nature of the Earth. If the air is burning, what sustains it at a constant composition? I also wondered about the supply of fuel and the removal of the products of combustion. It came to me suddenly, just like a flash of enlightenment, that to persist and keep stable, something must be regulating the atmosphere and so keeping it at its constant composition. Moreover, if most of the gases came from living organisms, then life at the surface must be doing the regulation.

We are the intelligent elite among animal life on earth and whatever our mistakes, [Earth] needs us. This may seem an odd statement after … the way 20th century humans became almost a planetary disease organism. But it has taken [Earth] 2.5 billion years to evolve an animal that can think and communicate its thoughts. If we become extinct she has little chance of evolving another.

We belong to the family of Gaia and are like a revolting teenager, intelligent and with great potential, but far too greedy and selfish for our own good.

When we burn fossil fuel for energy we are, in qualitative terms, doing nothing more wrong than burning wood. Our wrongdoing, if that is an appropriate term, is taking energy from Gaia hundreds of times faster than it is naturally made available. We are sinning in a quantitative not a qualitative way.