Gaia or Medea? The choice is ours
How lucky we are to be alive, and indeed that there should be life. Here we are after 4.8 billion years on a fragment of rock, air and water spinning round a star in a galaxy of billions of other stars in a universe beyond limits. How could it have happened? Tim Flannery tells this extraordinary story from what is known of its beginnings to the problems which one animal species - our own - has created not only for other forms of life but also for itself. He brings together planetary history, evolutionary biology, his own practical experience and some sinister as well as encouraging thoughts for the future. His book is a triumph of interdisciplinarity.
There are key players throughout the story. Charles Darwin and Alfred Russel Wallace dominate the 19th century. It is good to see Wallace given the credit due to him as a somewhat wayward genius. Since then understanding of how evolution actually works has rapidly advanced: from the mechanisms of genetics, including epigenetics, to the linkage between competitive selection of species and cooperation or symbiosis between them, often in bizarre and amazing ways.
As Flannery says of his own body: "billions of cells cooperating seamlessly at every moment and a brain made up of a reptilian stem, a middle mammalian portion, and two highly evolved yet relatively poorly connected hemispheres somehow add up to that thing I call me." It should be no wonder that some species, in particular ants and bees, have developed into collective organisms in which individuals operate almost as cells in a composite body such as Tim Flannery's.
Two other key players dominate the book. One is James Lovelock, the originator of Gaia theory. In a way that extends the idea of superorganisms of species into a superorganism of life in association with its physical environment, we have, in Lovelock's words "a self regulating system made up from the totality of organisms, the surface rocks, the ocean and the atmosphere tightly coupled as an evolving system".
How Gaia actually works once provoked a sometimes acrimonious debate, but more than thirty years on Gaia theory has moved from the fringes to the centre of earth systems science. The vital question is the nature of self regulation and the delineation of its limits, and what happens when the limits are breached.
Enter the next key player in Flannery's book: Peter Ward of the University of Washington. The essence of what Ward has labelled the Medea hypothesis is that as living organisms and superorganisms (including human society) multiply until they reach environmental or other limits, so they can diminish or destroy themselves. This has happened innumerable times in history, and is part of the process of evolution. As Flannery says, " ... for the brief moment that is the early 21st century, we strange forked creatures are perilously suspended between Medean and Gaian fates".
For thousands of years the forked creatures which are humans were simply part of the natural animal world. Some varieties of them - the Neanderthals, the so-called hobbits of Flores, and recently identified the Denisovans - became extinct. Our own variety first survived a major crisis which greatly reduced its numbers, but in the last 100,000 years has spread all over the Earth. All modern humans are pretty close cousins.
The biggest change of all took place with the industrial revolution beginning some 250 years ago in Britain. Since then humans have profoundly affected the Earth and all life on its surface, and are doing so more and more every day. Hence the proposal from some geologists that the current geological epoch, the Holocene, which began with the ending of the last ice age some 10,000 years ago, should be followed by the Anthropocene, an epoch in which humans have become the dominant feature.
Flannery looks at both sides of the Gaian / Medean relationship. Its main features are human multiplication, changes to the chemistry of land, sea and air, exploitation of often irreplaceable resources, degradation of soils, proliferation of wastes, pollution of water, and destruction of the other living species on which we wholly depend.
Because we live short lives and many of us enjoy the current bonanza of consumption, things can look good, and the idea that we may face a Medean future seems unlikely and anyway repellent. But Flannery well brings out not only the dangers but also the effects of the law of unintended consequences.
There has been, he says, an unconscious war against nature: for example no-one foresaw the full effects of the release of nuclear radiation, the use of chlorofluorocarbons in reducing protection from ultraviolet radiation, the use of agricultural pesticides, the spread of such toxic metals as mercury, and the increase of greenhouse gases in the atmosphere. In almost every case natural human instincts of acquisitiveness, fear of the unknown and preference for the easiest option have pushed things in the wrong direction. Putting them right, not only for humans but for other organisms, is extraordinarily difficult.
So what should happen next? There is a long and depressing list of things which need doing as soon as possible. Nearly all require us to think differently. Underlying most is the need to measure things differently so that the true costs of our actions, including externalities, are brought in. This means putting market forces into a framework of the public interest, and escaping from current obsessions about economic growth and consumption (our society has been well called the consumptive rather than the consumer society).
If we are to avoid an eventual Medean-type collapse, we obviously have to limit our numbers, as may be beginning already; go for different energy policies, also on the way; manage more sensibly what has been called the natural capital of the Earth; and establish the right kind of institutions for coping with global problems in what is increasingly a global society.
This means more respect not only for the environment but also for the other creatures within it. There are some who still think that essentially we can carry on as we are, and that technology will always solve our problems. As Flannery well shows, there is little evidence to support this view. He gives examples of some dotty technologies which were fortunately not developed in the past. New technology can sometimes create more problems that it solves.
One issue that Flannery does not take fully into account is the effect of the current electronic revolution on human communication, and beyond that the functioning of the brain. How and to what extent will our brains be left behind by computers? Do we face what has been called a singularity by the middle of this century in which non-biological intelligence will be immensely greater than all human intelligence put together?
This is a well written, persuasive and at times alarming venture into past, present and future. It may be easy to read but it is not always comfortable reading. It deserves to be widely read.