By Donella Meadows

–August 16, 1990–

“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,” says James Lovelock, originator of the idea that the earth is one integrated organism, which he calls Gaia.

The little upstart species that labels itself “Man the Wise” may be crushed by the revenge of a huge, angered planet. That’s one way to look at our present predicament.

Then there’s the other way, the fragile-earth theory, often expressed by astronauts and cosmonauts looking down from on high. Cosmonaut Sigmund Jahn of Germany: “Before I flew I was already aware of how small and vulnerable our planet is; but only when I saw it from space, in all its ineffable beauty and fragility, did I realize that humankind’s most urgent task is to cherish and preserve it.”

Is Earth fragile and vulnerable or tough and ruthless? Is it possible for us to trash a whole planet? Or is it about to trash us?

As far as we know the answer to those questions is yes/both. Relative to most energy and material flows on Earth the machinations of humankind are puny. But in a few sensitive places, we’re making an impact on a planetary scale.

Take energy, for instance. The human economy runs on a power flow of 10 trillion watts, miniscule compared to the 80,000 trillion watts that flow to the earth’s surface from the sun. In the global energy picture we’re hardly noticeable.

But the fossil fuels we burn give off enough carbon dioxide to raise the atmospheric concentration of that gas by 35 percent so far. We can have such a great effect only because carbon dioxide is a minor gas (0.03 percent of the atmosphere). Minor though it is, however, it happens to be positioned (in wavelength terms) right where it blocks the outflow of heat from the earth.

Which is to say, our energy use is trivial, but it throws a monkeywrench onto a critical valve that adjusts the heat balance of the whole planet.

We make only about a million tons of CFC gases year, inconsequential compared to the 50 million BILLION tons of the atmosphere. Not even much compared to the thin veil of ozone in the stratosphere. But chlorine released from CFCs happens to destroy ozone without being destroyed itself. A mere 30 years of human CFC production has punched a significant hole in the stratospheric ozone. That’s serious, because ozone protects all life from destructive ultraviolet radiation from the sun.

For another example of our smallness/bigness, take water. Humans use directly only 0.7 percent of the 500,000 cubic kilometers of rain that falls each year. But of that massive rain flow, most falls on the oceans or runs off the land in floods. Only 9000 cubic kilometers is dependable base flow of the earth’s accessible rivers. We use 3500 and pollute another 3000 — that is, we use or spoil more than two-thirds of the accessible freshwater runoff of the earth.

Our fertilizer factories fix 90 million tons per year of nitrogen from the air into nitrate and ammonia for the soil. That’s about as much as all nature does, which is to say we are doubling the flow of the natural nitrogen cycle. The result is population explosions of some soil organisms, die-offs of others, and nitrate pollution of rivers and groundwaters.

We dig phosphate out of the earth, also for fertilizer, and release it to the environment eight times faster than nature does. That creates, among other effects, green jello lakes clotted with algae blooms and dead fish. By processing ores and burning fossil fuels we release sulfur dioxide six times faster than nature does. The result is acid rain.

We mine mercury at a speed about equal to its natural rate of weathering from rocks; cadmium at a rate 30 times faster than natural weathering; lead 10 times faster.

These are all minor disturbances, given the enormous natural material flows on Earth, but they happen to be toxic to life — and life, not the planet, is what is threatened. Ecologists calculate that Homo sapiens now uses, burns, or poisons 25 percent of the photosynthetic product of Gaia — that is, 25 percent of the energy that powers all life (40 percent of the energy that powers life on land). And we expect our population to double within 40 years and our economy to double sooner than that.

James Lovelock came up with the idea of Gaia when he looked at the atmosphere of Mars (before we had sent any space probes there) and predicted that we would find no life there. Its atmosphere is in the perfect chemical equilibrium of a dead planet. Earth’s atmosphere, in contrast, is possible only if living things are constantly interfering with its chemistry, bringing forth an unstable, yet constantly regenerated mixture of gases, which proclaims to all the universe that here burns the elegant slow flame of abundant life.

That’s the flame we are appropriating, redirecting, supercharging in some places and snuffing out in others. We are nowhere near powerful enough to destroy a whole planet or to save it. With our swelling populations and industries, however, we are becoming powerful enough to destroy or save the living balance, the cycles of regeneration and rebirth that are created by and that support Gaia’s many forms of life — including ourselves.

Copyright Sustainability Institute 1990