Things are hotting up

Climate is what we most take for granted. Hence the prospect of change - hotter or cooler, wetter or drier - beyond the familiar limits of variability, has been an increasing anxiety. Some may relish the idea of a warmer Britain, with Bournemouth resembling Cannes and vineyards covering Salisbury Plain, but the implications for this green and well-watered island would be far reaching and certainly disruptive of our present way of life. Once current patterns were upset, we could not say where future ones would settle, nor predict what they would be. To the extent that human activity is changing climate, we are conducting an experiment in which we are unwilling participants, and which is likely to get progressively beyond our control. The best we can hope for is to mitigate some of the effects.

The problem is simply stated. There is a natural greenhouse effect which keeps the earth some 33xC warmer than it would otherwise be. But since the beginnings of the industrial revolution the way in which we generate energy, transport ourselves and use land for agriculture have begun to augment the natural effect. Over the last century atmospheric carbon dioxide has increased by some 25 per cent, and methane by 100 per cent. Throughout planetary history there has been a relationship between the quantity of such gases in the atmosphere and average global surface temperature. In industrial countries the warming effect is slightly and temporarily mitigated by small particles, or aerosols, generated by industrial activity, and everywhere by rock weathering and such biological agents as phytoplankton which draw carbon out of the atmosphere. But the broad judgement of themajority of the world's scientists, expressed in the most recent assessment of the Intergovernmental Panel on Climate Change, isthat human activity is already having a discernible effect on climate, and that this human signal can be distinguished from the natural noise of variability.

Major uncertainties remain. To judge from the evidence of the past, there are complex feedback mechanisms which can both mitigate and accentuate change. Such change often goes in steps rather than curves: thresholds can be reached, which, once passed, disturb the whole system before it settles again. The last 10,000 years have been a fairly stable period, but the 10,000 years preceding them saw substantial and often rapid change. We cannot yet predict regional effects. If warming of the Arctic were to upset the current system of ocean currents so that the benevolent Gulf Stream no longer heated Western Europe, the whole area could become much cooler, and more like parts of Canada on the same lines of latitude. Nor can we predict the effects on sea levels. A rise in global average surface temperature of around 2xC before the end of the next century could be matched by a rise in sea levels of half a metre.

The social and economic effects of changes of this kind, particularly if they come quickly, would be enormous. The world economy and the national economies within it would be radically changed. The problem for governments and the international community is to work out what can be done about issues that far transcend the power of any sovereign state, to determine the costs and benefits of measures which go beyond the methodology which most economists use in looking to the future, and to understand the linkages between climate change and the other major environmental problems of our time: human population increase, use of resources, disposal of wastes, application of new technologies, and destruction of other forms of life. We can no longer prevent climate change if we ever could (the residence time of carbon in the atmosphere is over a century). We can only mitigate the effects, and learn how to adapt ourselves to them.

The three books under review look at the issues in interestingly different ways. The subtitle of John Houghton's Global Warming, now in its second edition, is "The Complete Briefing". This well indicates the business-like and somewhat didactic character of the book with its precise account of the science, accompanied by figures, graphs, boxes on specific points, and summaries at the end of each chapter, with questions for students. As a former chief executive of the Meteorological Office, and co-chairman of the Scientific Assessment Working Group of the Intergovernmental Panel on Climate Change, the author is uniquely qualified. But he ranges beyond the science into the diplomacy, politics, economics and ethics of the problem, which together present a formidable challenge to human understanding and capacity for action.

Much has already been written about the difficulties. They arise not only from the genuine uncertainties but also from the inadequacies of current thought and linkages with other problems. Unlike most people, Houghton is ready to tackle these head on. He has a brave chapter on environmental values, the interdependency of life (as expressed through the Gaia hypothesis), human responsibilities in nature, and notions of stewardship. As a predatory animal species, we do more than any other to change and in many respects damage other living organisms and the general processes of life. As James Lovelock once said, we should no more expect humans to be stewards of the earth than goats to be gardeners. Yet we are not stupid. Sooner or later we have to accept our responsibilities. This book brings out what they are, and helps illuminate the way ahead.

In Does the Weather Really Matter? William Burroughs looks at the issues from the field of experience. It is weather rather than climate (its aggregate over patches of time) that matters to individuals now and in history. Again the subtitle is helpful: "The Social Implications of Climate Change". Such implications have changed our past and will increasingly shape our future. Climate in history is itself a fascinating theme, and here it is well described with new evidence. But now that we are better aware of what is happening, and how we may be influencing it, can we successfully model it, make realistic predictions, and then use the predictions in intelligent fashion? The answer is half yes, and half no. Existing general circulation models are the best we can do, and are being improved all the time. But they are critically incomplete, and even if they were better, action which might follow is bedevilled by changing human reactions to what is predicted. In short, as the author points out, they are not unlike Treasury predictions about the British economy: the methodology is imperfect, the variables are too many, and the results are in many ways subjective.

Yet progress is real. The human-made factors forcing change on the climate are now clearer, as emerged from the meeting of the World Climate Research Programme in August. For all the uncertainties and surprises that may await us, the directions of change for the world as a whole are also clearer. No one is more aware of them than food producers, banks and insurance companies. There are three obvious priorities: the better integration of social and economic with scientific factors; continued efforts to record and monitor information (at a time when research expenditure seems actually to be declining); and application of the precautionary principle (best expressed as readiness to take action before certainty can be achieved).

With Politics of Climate Change, Tim O'Riordan, Jill Jager and their fellow contributors enter the thickets of international action, or lack of it. The background is easily stated. Increasing public concern about climate led to two World Climate Conferences and the creation of the Intergovernmental Panel on Climate Change in 1988. This in turn led to the Framework Convention on Climate Change signed at the UN Conference on Environment and Development at Rio in 1992. The signatories then called for "stabilisation of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system". They did not say what this meant. Even to hold current levels would have meant drastic cuts no one would have accepted. But the industrial countries, which after all created the problem, agreed to lower their greenhouse gas emissions to 1990 levels by the year 2000, and the rest of the world agreed to less specific measures in return for help from the industrial countries.

With less than three years to 2000, it is clear that only three industrial countries - Germany, Russia and Britain - will meet their obligations. Virtually no help has been given to the rest of the world. As the biggest polluter of all, the United States will probably exceed its 1990 levels by 13 per cent, with further increases to come. It has done nothing to curb emissions, and petrol at the pumps is now cheaper than bottled water. The US Senate has affirmed its opposition to restraint unless the rest of the world, with its small per capita emission rates but now a strong sense of grievance, does likewise. The prospects for the next round of negotiations at Kyoto in December are thus bleak.

Politics of Climate Change is a detailed analysis of the political, institutional and legal aspects of the problem. It is, and probably will remain, the last word on the attitudes of European industrial countries, singly or collectively, towards the issues as they are debated in Kyoto and thereafter. Together the European Union is well ahead of other industrial countries; and the new British government has undertaken to reduce emissions by 20% below 1990 levels by 2010. But the complexities are immense, and even now few seem to realise the magnitude of the social and economic changes required.

The focus of the book on the institutional and legal aspects within the European Union and between its member states is interesting from the theoretical point of view, but occasionally ponderous and in a way misleading. The problems relate less to the niceties of constitutional or legal propriety and more to the defects of a world society, hooked like a fish on consumption of fossil fuels, and driven by ideas about "development" which, when environmental factors are taken into account (and China and India have got going as industrial countries), mean that pressure on the climate system will get very much greater before it can possibly stabilise in any sense. There are perhaps three main factors which could make for change. One is leadership from the industrial countries, so far conspicuous by its absence, not least in setting the example. The conceptual basis for joint action is still lacking. The second is popular pressure on the international community, governments and vested interests. That too is only beginning. The third is a catastrophe in which the consequences of human actions on the climate become manifest, with cause visibly leading to effect. Such is unlikely in the immediate future. More probable are regional or local disasters, particularly in poor and vulnerable parts of the world. Perhaps this year's forest fires in Indonesia are a harbinger. In the meantime the build-up of greenhouse gases will continue, and climate will be forced into new patterns of behaviour.

When the beliefs, assumptions and actions of our present society come to be weighed in the balance, they will be found strangely wanting. They will also be found surprising. New generations will be incredulous. They will wonder why we did not foresee and act on problems which were obvious, even in 1997. These three books, each prescient in its own way, will reinforce their astonishment.

Sir Crispin Tickell is warden, Green College, Oxford, and convenor, British Government Panel on Sustainable Development.