The human future
We know something of our past. We think we know the present. Some of us may see the future as a continuation of both. If so they are wrong. Today I want to look backwards, sideways and forwards, and venture into the long-term prospects for our species. This was a subject which much interested Lynn Margulis, with whom I discussed it many times.
First we need to establish the perspective. Humans are an infinitesimal part of the living world (0.00007% of estimated living species). Each of us has ten times more microbial than body cells. Our species is relatively new. No-one was around to record the evolution of the first human-like creatures from ape-like ancestors in Africa some four million years ago. They left the trees for the savannah, became relatively hairless, and walked upright on two legs, with consequences for the physiology of their growing brains. By at least half a million years ago they had split into a variety of related strains: among them were the Neandertals and (as recently discovered) the Denisovans. Another offshoot may still have been living on the Indonesian island of Flores as recently as 16,000 years ago (a mere blink in geological time).
So far through analysis of fossils and work on current humans, we have been able to trace the genealogy of Homo sapiens back some 200,000 years. All other branches of humans are now extinct, but many of us share at least a small proportion of their genes.
Over the last 40,000 years the human impact on the Earth has slowly and then rapidly increased. Hunter gatherers fitted easily, although sometimes uncomfortably, into the ecosystems of the cold and warm periods of the Pleistocene epoch. People migrated in response to changing conditions but farming with land clearance between 10,000 and 8,000 years ago changed everything. With a vast increase in human population came towns and eventually cities. Tribal communities evolved into complex hierarchical societies. For a rich variety of reasons such societies rose and fell, and usually, but not always, recovered. The pulse of civilization has always been irregular.
Before the industrial revolution some 250 years ago, the effects of human activity were local, or at most regional, rather than global. Now the impact is indeed global, indeed as you have heard, we have the idea of a new geological epoch - the Anthropocene - to mark the effect that human activity has had on the surface of the Earth, and will have in the future.
Indeed in its long history with all its variations the Earth has never been in this situation before. Nor has life in its myriad manifestations. It was Lynn Margulis who described Gaia - or the living Earth - as a "tough bitch". So she is. Today Lynn Margulis's contribution to evolutionary theory is being celebrated by others at this Symposium. I say simply that the introduction of the idea of symbiosis into the Darwinian processes of natural selection, in short cooperation as well as competition between species, is now essential to our understanding of evolution. As she also said almost 20 years ago, symbiosis is "a mechanism of evolutionary innovation."
In the meantime human actions are transforming the Earth, and will do so even more in the future. In my view there are six main factors which have driven this transformation, and will continue to do so in the future. Of these population issues are often ignored as somehow embarrassing or mixed up with religion; most people are broadly aware of land resource and waste problems, although far from accepting the necessary remedies; water issues, both fresh and salt, have had a lot of publicity, and already affect most people on Earth; climate change with all its implications for atmospheric chemistry and sea level rise is also broadly understood, apart from those who do not want to understand it; how we generate energy while fossil fuel resources diminish and demand increases is another conundrum; but damage to the diversity of life on which our species critically depends has until recently escaped the attention it should have received.
Here we remain ignorant of our own ignorance. Yet in this area human destructiveness has been most evident over the last 10,000 years. Current rates of extinction could in the long run be the most important of all these factors for human welfare and the future of our species. All are interlinked, and all represent pressure on the natural environment.
There is now a seventh factor recent in human experience. It arises from the introduction of new technologies, the most recent of which was the digital. In a recent book Martin Rees, former President of the Royal Society, explored the dangers arising from human inventiveness, folly, wickedness and sheer inadvertence (for example the effects of plastics on ocean chemistry and the organisms within it). The ramifications of information technology, nano-technology, nuclear experimentation and the rest have still to be understood and explored. His conclusion was to give our civilization only a 50% chance of survival beyond the end of this century.
What then are we to expect? How are we to recognize that the last 250 years or so have been a bonanza of inventiveness, exploitation and consumption which may not continue? All successful species, whether bivalves, beetles or humans, multiply until they come up against the environmental stops, reach some accommodation with the rest of the environment, and willy-nilly restore some balance. The penalties for not doing so can lead to collapse. Are we near to those stops? To judge from the current debate within the scientific community, we are pretty close to them.
We can all have our own lists and calculations of the dangers. I have already suggested some of mine. Going back to them, I have no doubt that we have to rethink how we run our society. That means confronting the major issue of our own multiplication in all its aspects (ten thousand more humans every hour and almost eighty million every year), what has been well called global swarming; looking again at a lot of economics and how we measure things; deciding where our future energy supplies should come from; giving high priority to conservation of the natural world; dispersing and to some extent localizing the ways by which we feed ourselves; managing and adapting to climate change (or as I prefer to call it climate destabilization); and challenging the conventional wisdom even in science with its somewhat mechanistic interpretation of the natural order.
We all suffer from a disease of what has been called conceptual sclerosis. Little is more difficult than learning to think differently. Old ideas haunt us like ghosts.
So what kind of future can our species expect in a world which is changing under human pressure before our eyes? What can we expect of the Anthropocene? Bear in mind that nearly all forecasting turns out to the wrong. We do well to expect the unexpected.
There are the obvious challenges. Some relate to the Earth as a whole: for example the natural disruptions known throughout history, volcanic explosions, earthquakes, impacts of extraterrestrial objects, and variations in species and ecosystems, in short the whole evolutionary process. Climate is always changing, with profound sometimes rapid effects on the natural world. Then there are the specific problems of humanity, including the widening divisions between rich and poor within and between countries, shortages of food and water, loss of confidence in ruling elites, the effects of large-scale migration, the high vulnerability of cities, the growth of terrorism, the risks of war with unimaginably horrible weapons, and the exhaustion of often irreplaceable resources.
But this is not the whole story. Before and during the Anthropocene, the balance of power shifted towards Europe, the United States and to some extent Japan, and away from China, India and the Middle East. Now, following the end of the cold war, things are changing.
This is a huge subject in itself: political, social, economic and technological. It coincides with the current crisis within what is loosely called capitalism, and the relationship between industrial and other countries (the so-called developed, developing, under developed and even over developed countries). Indeed such changes may come to represent the most important for hundreds of years, and they seem to be accelerating.
The implications for governance reach equally wide. In some areas good regulation will be more important than ever. In the words of the title of a recent book, we have to recognise that most things fail, whether they be natural organisms or human institutions. Petty nationalism may be on the increase, but there is a clear movement of power away from the nation state: upwards to global institutions and corporations to deal with global issues; downwards to communities of more human dimensions; and sideways by electronic means betweens citizens everywhere.
- Upwards we need better means to cope with global issues, including an enforceable international legal system in the common human interest. For long I have been the advocate of a World Environment Organization to bring together the 200 or more limited, often overlapping, detailed agreements on environmental issues, and to act as a global umbrella over them.
- Downwards we need to bring in a much stronger sense of collective responsibility at national, regional and local levels (hence ideas for a Big Society). Here results are clearly inadequate so far, and we have much more to do.
- Sideways we need to engage individuals and endow them with stronger feelings of personal engagement. Here we are seeing extraordinary advances: for example widespread access to the internet (in spite of the efforts of some governments to censor it), and the spread of mobile telephones even in poorer parts of the world, which promotes communication of a kind hitherto impossible. We have yet to reckon with the consequences.
Even so there remains a major problem of communication between the scientific world on one hand and the political and media worlds on the other. It can take a dangerously long time for discoveries in science to become intelligible to the rest of society. I have been involved in a specifically climate education programme fostered by NASA in the United States. Our prime educational device is what has been called Science on a Sphere, a model of the Earth roughly two metres in diameter on which changes, whether in tectonic plate movement over millions of years, climate change over thousands of years, or day by day weather patterns or even aircraft movements, can be displayed. Such Spheres, now distributed in many parts of the world, attract fascinated audiences and appeal to our increasingly visual understanding of the changes taking place in the world around us.
It would be rash to attempt to forecast how the world will look even a hundred years from now. But it may be useful to jump that hundred years, and from this vantage look backwards. In doing so, I shall assume, I hope correctly, that humans will have faced up to and coped with at least some of the problems I have discussed. The Anthropocene epoch will certainly continue. As in the past, there will be failures and collapses. So what is my guess for what the world will look like?
First humans are likely to be living in a more globalized world of rapid communication. Here is an obvious consequence of current technology. Ideas and units of information - or memes - will pass almost instantaneously between countries, communities and individuals. The wiring of the planet with fibre optics, cellular wireless, satellites and digital television is already transforming human relationships. More than ever in the past there will be something like a single human society and civilization. Like certain species of ants, humans can be regarded as a superorganism. But also like ants there will be fierce competition between groups and communities, more than ever anxious to maintain and express their identity.
Human numbers in cities and elsewhere are at present rising fast, but it is hard to believe that this can or will continue in the second half of this century. By 2112 our numbers will almost certainly be diminishing. There are signs of this happening already. Some people will live longer, bringing its own train of problems. Their distribution will be different. Women will have a more important role. In many parts of the world they are already achieving their long deserved equality with men. This will have enormous effects on the management of society. It has been suggested that an optimum population for the Earth in terms of its resources would be nearer to 2.5 billion rather than - as now - 7 billion or even 9 billion by mid-century.
Communities are likely to be more dispersed without the daily tides of people flowing in and out of cities for work. Current obsessions with so called growth and ever-increasing consumption will be replaced by the need to make better use of resources, respect the natural capital of the Earth, and measure health, wealth and happiness in a more rational way.
Application of new digitized technologies is already changing the character of manufacturing. Agriculture will be more local and specialized with greater reliance on hydroponics. Energy and transport systems will be decentralized. Archaeologists of the future may even wonder what all those roads were for.
On the one hand some humans may thereby be liberated from many current drudgeries. Houses may be able to clean themselves, robots may produce meals on demand, cars may drive under remote instruction, and evolution of desirable characteristics could even be automated. All this seems hardly imaginable when so many still have to trudge miles to collect fuel, wood and water.
On the other hand humans could well become dangerously vulnerable to technological breakdown, and thereby lose an essential measure of self sufficiency. Fewer people will produce more and the character of employment will change radically.
All this raises deeper questions about evolution. Changes are already taking place in the human organism, for example in resistance, or lack of it, to certain diseases. We are capable of manipulating or altering some genes, and can even insert extra chromosomes for a limited variety of purposes. Who knows what we will do next? Genetic enhancement is a real if awkward possibility. Will the rich eventually choose the best genes for their children? With what result for the rest?
Already it has been shown that the current electronic revolution and the daily deluge of information it has produced can have big effects on the brain, the most remarkable part of the human body. Revolutions of the past, for example the invention of writing, slowly changed the way in which we stored information and made use of it. Some parts of our memory store emptied and others filled up.
Now the problem is changing. Instead of putting information together and taking a relatively unified view, we are reacting to a multiplicity of bits of fast moving information and dealing with the bits as best we can as they come. In short we are no longer so good at seeing the wood for the trees, or even seeing the trees for the twigs. Many people, particularly among the younger generation, are less interested in words, for example in books, than in visual images on screens and the internet. Some people even prefer to text rather than talk to each other. The physical functioning of our brains may already be changing; and the notorious tilt between the left and the right hemispheres with it.
We may also be up against the physical limits of our brains. A honey bee, with its milligram-size brain, can perform tasks such as navigating landscapes on a par with mammals; while elephants with their five hundred million fold larger brains, need more than a hundred times longer for their signals to travel between the opposite sides of their brains, and from their brains to their feet. So any increase in size, even if it were feasible, would not necessarily increase human intelligence. It would be better to follow the example of the bees. Small can be beautiful after all.
These problems may look far away. Let us hope without total confidence that by 2100 humans will have worked out and will practice an ethical system in which the natural world has value not only for human welfare but also for and in itself. The human superorganism must take its place alongside other superorganisms.
The penalties for failure to respect the natural world are enormous. Lynn Margulis once speculated on what she called the big-headed delusions of mankind. I quote:
"I hear our non-human brethren sniggering. 'Got along without you before I met you, gonna get along without you now' they sing. Most of them, the microbes, the whales, the insects, the seed plants and the birds, are still singing. The tropical forest trees are humming to themselves waiting for us to finish our arrogant logging so they can get back to their business of growth as usual. And they will continue their cacophonies and harmonies long after we are gone."
I sometimes wonder how long it would take for the Earth to recover from the human impact. Future visitors from outer space - say thousands of years from now - might well be puzzled by the fossil remains of ourselves and the agglomerations we call cities, in short the relics of the Anthropocene. They might also wonder at the fossils of the other animals and plants we have so abruptly adapted for our own purposes. In the future rats could be as big as dogs, water hyacinths could block lakes, and microorganisms could go macro. But they should know, as should we, that life itself, from the bottom of the seas to the top of the atmosphere, is so robust that the dominance of any one species could be no more than a relatively short episode in the history of life on Earth.
Above all we must recognize how small and vulnerable we are as members of a particular species in a particular environment at a particular moment in time. Let us enjoy it while we can.