Challenges to the human future: prospects and hazards
To look forward we first have to look back. I begin by reminding you, if you need reminding, that humans are only one species among the millions that exist or have existed since the beginning of life almost four billion years ago. We are a tiny part of a global environment which is limited, ephemeral, and precarious. It is just that the shortness of our lives and the narrowness of our perspective on Earth history mean that we are mostly unaware of change, and until now have scarcely noticed the human impact on the environment.
The last couple of centuries have seen an extraordinary stretching of our understanding of space and time. We can now look beyond the solar system, beyond our galaxy, beyond billions of other galaxies, back to the big bang which initiated the universe we know. As for time, we can look beyond the last thousand years, beyond the beginnings of civilization, beyond the patch of warmth in the last 12,000 years, beyond the many spasms of the ice ages, beyond multicellular, eukaryotic organisms, and further back to the origins of life itself.
During these almost unimaginable stretches of time, there have been big hits from space, the changing relationship between the Earth and the Sun, the slow movement of tectonic plates on the Earth's surface, the rise and fall of sea levels, major volcanic eruptions, and not least the influence of life itself. The tightly linked living organisms on the Earth's surface tend to create and maintain the environment most favourable to them. Over time the system has tipped many ways, sometimes violently, to the detriment of this or that group of organisms. There have always been correctives. Yet today one small animal species - our own - is tipping the system in ways that cannot be foreseen.
That species is very 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 learned to walk 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, and spread far beyond Africa. One of their offshoots may still have been living on the Indonesian island of Flores as recently as 12,000 years ago (a mere blink in geological time). Our own lot can first be identified between 200,000 and 150,000 years ago.
Evidence for humans with modern attributes, as seen for example in cave paintings, goes back some 40,000 years in Europe, but shell and coral beads and other artefacts, including pigment, have been found in South Africa and dated from around 75,000 years ago. Perhaps the answer is both factors. Whenever the change took place, the extraordinary development of human brain power, which has produced ourselves, occupies much less than 1% of all human history.
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 cold and warm periods of the Pleistocene. People migrated in response to changing conditions. But farming with land clearance between 10,000 and 8,000 years ago changed everything. It may even have changed the climate and, by affecting emissions of carbon dioxide and methane into the atmosphere, halted a return to colder conditions. With a vast increase in human population came towns and eventually cities. Tribal communities evolved into complex hierarchical societies. Before the industrial revolution some 250 years, the effects of human activity were local, or at most regional, rather than global. Now the impact is indeed global. We face what Al Gore has described as a planetary emergency.
The idea may be hard to accept, but in its long history with all its variations the Earth has never been in this situation before. In the words of the title of a recent book on environmental history, we confront Something New Under the Sun. The problem is almost on a geological scale. No wonder the Nobel prize winner Paul Crutzen with his colleague Eugene Stoermer should have named the current epoch the Anthropocene, in succession to the Holocene epoch of the last 10,000 years.
There are six main factors which have driven this transformation. All affect our future. Briefly they arise from human population increase; degradation of land, consumption of resources and accumulation of wastes; water pollution and supply; climate change in its many aspects and impacts; energy production and use; and destruction of biodiversity.
Of these factors population issues are often ignored as somehow too embarrassing or mixed up with religion and the ideology of development; most people are broadly aware of land resource and waste problems, although far from accepting the remedies necessary; water issues, both fresh and salt, have had a lot of publicity, and already affect most people on this planet; climate change with all its implications for atmospheric chemistry is also broadly understood, apart from by 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 somehow escaped most public attention. Yet here 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. All are interlinked, and all represent pressure on the Earth's environment.
There is now a seventh factor recent in human experience. So far the effects remain mostly to be seen. They arise from the introduction of new technologies. Damage to the ozone layer, which protects ecosystems from harmful ultraviolet radiation from the Sun, was the first to receive major public attention. Here we only just missed disaster. The eventual result was to establish international agreements to ban the manufacture and use of chlorofluorocarbons. But this may only be the beginning. In a recent book by the President of the Royal Society, Sir Martin, now Lord Rees explored the dangers arising from human inventiveness, folly, wickedness and sheer inadvertence. The ramifications of information technology, nano-technology and 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? Are we capable of establishing a lasting relationship of mutual benefit to the living Earth and those of its unruly inhabitants who are ourselves? How are we to recognize that the last 200 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. In the long history of the Earth, we are the only species capable of recognizing that the problems outlined above exist, and that sooner rather than later something has to be done about them.
In fact most of the solutions to the problems we are causing are well known. This is not the occasion for going through them. Briefly we have to rethink a lot of economics. replace consumerism as a goal, give high priority to conservation of the natural world, disperse agricultural production, work out new ways of generating energy, and create the necessary institutional means of coping with global problems. There are thousands of miniscule ways in which we will have to rethink the ways in which we run our daily lives. We all suffer from the disease of what has been called conceptual sclerosis. Little is more difficult than learning to think differently, above all when problems go to the roots of the conventional wisdom.
It is time now to turn to the future of our species in a world which is changing under human pressure before our eyes. This is the world which you and your children will inhabit. As I am sure members of the New Generation Society well know already, the future will not be a simply continuation of the present. Yet bear in mind that nearly all forecasting turns out to be wrong. At every point there is always the choice of alternatives. We do well to expect the unexpected.
In his book The Meaning of the 21st Century, James Martin laid out what he saw as the prospects.
"The 21st century is like a deep river canyon with a narrow bottle neck at its centre. Think of humanity as river rafters heading down stream. As we head into the canyon, we'll have to cope with a rate of change that becomes much more intense - a white water raft trip down an unknown river with the currents becoming much faster and rougher - a time when technology will accelerate at a phenomenal rate."He went on to identify the main challenges facing us. Some relate to the Earth as a whole: for example the natural disruptions known throughout history, volcanic explosions, earthquakes, impacts of extra terrestrial objects, changing climates, and variations in ecosystems, including patterns of disease. Other challenges relate specifically to humans, and their ability to force change as well as to respond and adapt to it. On this James Martin wrote:
"As the population climbs, global tensions and pollutions will grow and the danger of massive famines will increase. The population of the world will continue to grow... The capability to feed such a population will steadily decrease as water tables drop, farms in poor countries are abandoned, and the huge new consumer class in China, India and 18 other countries changes its eating habits so that it consumes more meat (which needs much more grain, and hence enormously more water for grasslands)."In turn this will affect human migration between countries and continents, widening divisions between rich and poor within and between countries, increasing the vulnerability of cities, promoting the growth of terrorism, increasing the risks of war with unimaginably horrible weapons, and exhausting often irreplaceable resources. On this reckoning we will be lucky to come out the other side of the deep river canyon with anything like civilization as we know it.
But this is not the whole story. I want now to jump a 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 these problems. People are not stupid. So what will the world look like?
First they are likely to be living in a more globalized world of rapid communication. Ideas, 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. For the first time there will be something like a single human civilization.
Human numbers in cities or elsewhere will almost certainly be reduced, but some people will live much longer, bringing its own train of problems. Their distribution will be different. 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 - over 6 and a half billion, or even 9 billion later this century. Communities are likely to be more dispersed without the daily tides of people flowing in and out of cities for work. Agriculture will be more local and specialized with more reliance on hydroponics. Energy and transport systems will be decentralized. Archaeologists of the future may even wonder what all those roads were for.
Then there are other developments in information technology. Here come the most radical possibilities of all. So far evolution has proceeded by natural selection in its various aspects. In the last few thousand years humans have played games with it through artificial breeding of organisms - from cereals to cows and dogs - to suit their purposes. Such processes were always slow. But now through lateral gene transfer, humans may rapidly be producing new varieties, sub species and even new species. This could apply to humans themselves.
H. G. Wells invented Eloi and Morlocks (those up above and those down below). At the time, more than a century ago, it seemed an amusing fantasy. No longer. Redesigning humans has become a real possibility. It is worth remembering how vulnerable even the Eloi were.
This raises the question of evolution itself. At present we can alter isolated genes while disregarding the totality of what genes can do. James Martin has distinguished what he has described as primary, secondary and tertiary evolution. He suggests that:
"Primary evolution is the mutation and natural selection of species - a glacially slow process ... Secondary evolution refers to the intelligent species learning how to create its own form of evolution. It invents an artificial world of machines, chemical plants, software, computer networks, transport, manufacturing processes and so on. It leans how to manipulate DNA ... Tertiary evolution refers to something which is just beginning on Earth. An intelligent species learns to automate evolution itself."
The idea of automated evolution needs some explanation. In a phrase it represents a vast acceleration of change. James Martin writes that with the machines we envisage today, it could be a billion times faster.
"Furthermore it will be incomparably more efficient. Darwinian evolution is described as being random, purposeless, dumb and Godless. Automated evolution is targeted, purposeful, intelligent, and has humans directing it and changing its fitness functions on the basis of results. In Darwinian evolution, the algorithm stays the same. In automated evolution researches will be constantly looking for better techniques and better theory. The techniques of evolvability will themselves evolve."Other applications of information technology range far beyond enumeration. Already chips have been inserted into humans for a variety of purposes. We can even insert extra chromosomes in the knowledge that they would not be heritable. On the one hand humans may thereby be liberated from many current drudgeries. Soon houses will may be able to clean themselves, meals could appear on demand, cars will drive under remote instruction, and evolution of desirable characteristics could even be automated. All this seems unimaginable 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. Already dependence on computers to run our complex systems, and reliance on electronic information transfer, are having alarming effects. Here industrial countries are far more vulnerable than others. Just look at the effects of single and temporary power cuts. More than ever individuals feel out of control of even the most elementary aspects of their lives.
The implications for governance reach equally wide. In some areas good regulation will be more important than ever, particularly in nano technology. In the words of a recent book, we have to recognize that most things fail, whether they be organisms or human institutions. Already there is a movement of power away from the nation state: upwards to global institutions and corporations to deal with global issues; downwards to communities of human dimension; and sideways by electronic means between citizens everywhere.
There is a wide range of possibilities including forms of dictatorship and disaggregation of society. The problems of politics will be as difficult as they are today: how to ensure greater citizen participation without creating chaos; how to establish forms of accountability to ensure that governance is by broad consent; and how to establish checks and balances to protect the public interest, and ensure enforcement without abuse. Current rhetoric about democracy well illustrates some of the dangers. Populism can too easily corrode values, and democracy can produce abusive results.
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. They may also be involved in spreading life beyond the Earth and colonizing Mars or other planets. The opportunities for our species seem as boundless as the hazards.
I sometimes wonder how long would it take for the Earth to recover from the human impact. How soon would our cities fall apart, soils regenerate, the animals and plants we have favoured find a more normal place in the natural environment, the waters and seas become clearer, the chemistry of the air return to what it was before we polluted it? Life itself, from the bottom of the seas, to the top of the atmosphere, is so robust that the human experience could become no more than a short and certainly peculiar episode in the history of life on Earth.
Above all let us remember how small and vulnerable we are as creatures of a particular environment at a particular moment in time. We are like microbes on the surface of an apple, on an insignificant tree, in an insignificant orchard, among billions of other insignificant orchards stretching over horizons beyond our sight or even our imagining.