A darker future for our pale blue dot

Is the world edging closer to destruction? Crispin Tickell is sceptical

The title of this book, Our Final Century , originally ended with a question mark. The same went for the title of the US edition, Our Final Hour . Along with the subtitle, The 50/50 Threat to Humanity's Survival , the publishers clearly want to make our hair stand on end.

Do they succeed? Up to a point. But I suspect that many people will approach this book by the astronomer royal with the scepticism born of knowledge of previous forecasts of apocalypses that were never fulfilled.

From biblical times to our own, "the end is nigh" has been the chorus line of fanatics of all descriptions. More recently, some political leaders, drawing on scientific advice, have also held their breath - for example, during the nuclear confrontations of the cold war. Only two years ago, scientists from the four great global research programmes met in Amsterdam and concluded that human activities had put the earth in a "no analogue state", and that the business-as-usual way of dealing with the earth system was "not an option".

The central thesis of this book, originally a collection of essays, is that "humanity is more at risk than at any earlier phase in its history". Over more than 3 billion years, our ancestors have known every kind of natural disaster, from super-volcanoes to asteroid impacts, and extinctions of species are commonplace in evolutionary history. Our disappearance would be no exception. We would not even be here, at least in our present form, if the Chicxulub impact of 65 million years ago had not drastically changed the prevailing earth ecosystem, removed the last of the dinosaur family and opened the way for the development of mammals. Natural disasters have repeatedly affected human history since the end of the last glaciation some 10,000 years ago. Of the 30 or so urban societies that have developed since then, only our own remains.

The prime element for which there is no analogue is the industrial revolution and the ever-developing technologies that underpin it. The last century saw an extraordinary acceleration of human knowledge and its myriad applications. The acceleration continues, although its consequences cannot be predicted. Certainly, its effects on our prospects for survival are with us every day.

The linked problems of human population increase, resource depletion, disposal of wastes, pollution of land, water and air, climate change and destruction of biological diversity are getting worse. They certainly affect us all, but the survival of civilisation or even the human species is not at risk. For most people they seem indirect, and a catastrophe or two, with cause clearly linked to effect, might be necessary before radical action is taken.

More direct threats fall into three broad categories. First, there are deliberate actions by governments equipped with weapons of major destructive power, whether nuclear or biological. These are the stuff of the debate over the alleged axis of evil. There is also inaction by governments confronted by the global environmental issues. Second, there are the deliberate actions of individuals or groups driven by ideology and the desire to change the established order. Their ability to damage vulnerable industrial societies was demonstrated on September 11 2001.

Third, there are the sometimes inadvertent activities of scientists or engineers who might, at least in theory, destroy the world, or even the universe, by mistake, for example with a particle accelerator. So far we have been lucky, but there have been one or two near misses, although of much lesser proportions.

Actions in the first category are familiar. In broad terms the United Nations, itself a combination of governments, was set up to cope with wayward governments in regard to global issues, especially those of peace and war. At present there is another self-appointed world policeman, but even he finds it hard to cope with anything but governments. The problem is that governments are far weaker and less in control than they ever were in the past.

Actions in the second and third categories are far more difficult to deal with. The implications of terrorism reach far. Measures to detect and limit it create almost as many problems as they solve. Control of scientists and engineers, and strict application of risk-assessment procedures to their work would scarcely be practical in any but a few cases. Nowhere are there easy answers. The management of human impacts on the earth system is one of the central issues of our time.

This is a book that has rightly attracted attention. It makes easy and persuasive reading and, above all, serves as a stimulus to thought. I would have liked more on natural hazards, such as the evolution of new diseases such as Aids and Sars (severe acute respiratory syndrome). Some of the arguments are a bit disconnected, but the author marvellously brings out both the dangers and the inherent limitations on our understanding of them.

I may be a bright-eyed optimist, but I wonder whether he is right in saying that "the odds are no better than 50-50 that our present civilisation on earth will survive to the end of the present century". I have greater faith in human ingenuity and good sense, at least once the problems are recognised. It was the first astronauts who saw the world, as Carl Sagan expressed it, as "a pale blue dot" in the vastness of the universe. We need to remind ourselves every day that its care, and that of the people on it, now and to come, must be our absolute priority.

Sir Crispin Tickell is visiting fellow, Center for the Environment, Harvard University, Massachusetts, US.