The Gaia Hypothesis

Life abounds on our planet, but is the planet alive?

By Peter McKenzie-Brown In Plato’s Greece, the word hubris meant something quite different from the idea of overbearing confidence or pride which we think of today. If mortals, out of hubris, did something to offend the gods, those very gods would punish the offender. People and gods had different roles in the world, and people, who were the subordinate players, needed to take care.As this book looks to the future, it needs to consider how to temper hubris with humility.

This history has made several references to global warming. Science has demonstrated that these developments are, beyond reasonable doubt, clear and present outcomes of fossil fuel consumption. This activity is already affecting Alberta oil sands, for example.

As far as oil sands operations are concerned, the risk of forest fire disruptions has been on the rise for more than a decade. That was the view of Mike Flannigan, director of the University of Alberta’s Western Partnership for Wildland Fire Science. “Global warming and climate change are real,” he said, “and they are affecting the way the oil sands business operates.”

He said it was no coincidence that Earth’s hottest ten years all took place in the 21^st century. Indeed, the 2014-2015 meteorological winter – from the beginning of December to February 28^th – was the warmest Earth had seen since record-keeping began, more than 135 years ago. Another piece of evidence: Alberta’s official fire season now starts March 1 – a full month earlier than only five or 10 years ago.

Thomas Newcomen invented the first commercial true steam engine, and in 1712 it quickly found a role pumping water out of coal mines in northern England. As we have seen, since that time, industry has found ever more uses for hydrocarbon-fuelled machines, which meant that fewer and fewer people could produce more with less effort.

The outcome? “It is wholly a confusion of ideas to suppose that the economical use of fuel is equivalent to a diminished consumption. The very contrary is the truth.” The coal and petroleum stored deep within Earth over hundreds of millions of years began to burn around the world, disturbing an equilibrium developed over long periods of geological time.

Imagine our planet as a living creature – bigger, more ancient and more complex than anything we could have imagined before. That concept isn’t new – many peoples have seen Earth and our seas as members of a pantheon of gods and goddesses. One of those names, Gaia, is a transliteration of the name for the Greek goddess representing Earth. It has also been transliterated into the Latin alphabet as “Ge,” and is a root for the words “geography,” “geometry” and “geology”.

In September 1965, the British thinker James Lovelock – with early support from Lynn Margulis, an American, and other colleagues – came up with a notion he later developed into what he called the Gaia hypothesis.

Because of his involvement with America’s Jet Propulsion Laboratory, which played a role in the American space program, Lovelock had given considerable thought to issues related to interplanetary space. So when the discussion turned to searching for life on nearby planets he suggested searching for the reversal of entropy – the tendency of closed systems to move endlessly toward greater disorder – a situation every teenager’s parent observes in that boy’s or girl’s bedroom. Put another way, the idea was to see whether there were any systems in Mars or Venus that organized themselves, rather than moved toward increasing disorder. His observation, of course, reflected the reality that living systems on Earth continually reorder themselves – that is, reverse entropy.

 Lovelock explains the concept in his autobiography. “Chance favoured me with a view of the Earth from space and I saw it as the stunningly beautiful anomaly of the solar system – a planet that was palpably different from its dead and deserted siblings, Mars and Venus,” he said. “I saw Earth as much more than just a ball of rock moistened by the oceans, or a space ship put there by a beneficent God just for the use of humankind,” he said. Since the planet originated nearly four billion years ago,  it “kept itself a fit home for the life that happened upon it and I thought that it did so by homeostasis, the wisdom of the body, just as you and I keep our temperature and chemistry constant. In this view the spontaneous evolution of life did more than make Darwin’s world: it created a joint project with the evolving earth itself. Life does more than adapt to Earth; it changes it, and evolution is a tight-coupled dance with life and the material environment as partners and from the dance emerges the entity Gaia.”

After publishing his book about Gaia, Lovelock received a mountain of criticism from other scientists. To express the idea in another way, he developed a mathematical model which he called Daisyworld. While never expecting it to be more than a caricature, he later called it “my proudest invention” – a model that served as “a parable about Gaia and Earth System Science.” He later developed it into a computer simulation, which uses a simple model of a planet with two kinds of daisies (one slightly darker than the other) and a sun which, like the one in our solar system, has been growing progressively brighter and warmer for billions of years. Although controversial still, to many his model helped confirm the theory.

From far away it is possible to see Earth as a living planet, according to the Gaia hypothesis. The atmospheric compositions of its sister planets, Venus and Mars, are 95-96% carbon dioxide, 3-4% nitrogen, with traces of oxygen, argon and methane. By contrast, Earth’s atmosphere is 79% nitrogen and 21% oxygen, with traces of carbon dioxide, methane and argon. By itself, the composition of our atmosphere would cause interstellar atmospheric scientists to scratch their collective heads, since oxygen has a habit of oxidizing everything in sight, forming stable compounds. Similarly, nitrogen forms nitrates, which logically should simply dissolve into seas, lakes, and oceans. According to Lovelock, the difference was Gaia, which transformed the outer layer of the planet into environments suitable for further growth. For example, bacteria and photosynthetic algae began some 2.8 billion years ago, extracting the carbon dioxide and releasing oxygen into the atmosphere, setting the stage for larger and more energetic creatures powered by combustion.

As Lovelock explained the system, self-regulating feedback mechanisms keep the planet habitable despite extreme disequilibrium everywhere. The elements in the atmosphere are remarkably stable – indeed, they are optimal for Earth’s dominant organisms. Gaia mostly hosts carbon-based life, and those organisms require oxygen to breathe and low levels of carbon dioxide in the atmosphere to maintain moderate temperatures. Indeed, for billions of years the brightness of the sun has been increasing, which means that, if carbon sequestration had not developed naturally, reducing to trace amounts the presence of carbon dioxide and methane in the atmosphere, the temperature of our planet would have been increasing instead of undergoing billions of years of decline.

To a large degree through the agency of microorganisms, Earth developed systems for storing these molecules safely away. “The continental shelves may also be vital in the regulation of the oxygen-carbon cycle,” Lovelock said. “It is through the burial of carbon in the anaerobic muds of the sea-bed that a net increment of oxygen of oxygen in the atmosphere is ensured. Without carbon burial, which leaves one additional oxygen molecule in the air for each carbon atom thus removed from the cycle of photosynthesis and respiration, oxygen would inevitably decline in concentration in the atmosphere until it almost reached the vanishing-point.”

If the Gaia hypothesis reflects what industrial hubris may have wrought upon our planet, the petroleum industry’s recent response to the issue does not reflect the environmental optimism that Rick George, for example, displayed. In the 1990s responded to criticism from environmentalists by encouraging debate about climate change, and increased their investments in renewable energy. The higher oil prices following the Great Recession, however, led the industry to scale back its loss-making green-energy businesses. Instead, they invested heavily in petroleum production and development.