How predictable is nature?

UNESCO Courier, May, 1998 by Jens Erik Fenstad

The future of science is not what it used to be. The optimistic public perception that scientific insights and technological advances would provide a better future has suffered a severe setback. Such "benefits" of scientific progress as atomic power, new chemical compounds and foodstuffs produced by genetic manipulation now generate uncertainty, even fear, as to what the future holds in store for man and nature

The post-war period was a good time for modern science-driven technology: it had played a decisive part in the allied victory and now it was to be harnessed to the tasks of post-war reconstruction, promoting increased welfare, better health and improved security. Few were troubled if at times scientists and engineers showed little concern for the preservation of nature - after all, the aim of technology has always been to transform nature for the benefit of humanity. There may, however, be limits to what nature can tolerate.

Relatively few doubts were raised until the United Nations World Commission on Environment and Development issued its report, Our Common Future, in 1987. By that time there was growing concern about the environmental problems progress was bringing in its wake: the fossil fuels used in industrial development were increasing the carbon dioxide content in the atmosphere, threatening to create a greenhouse effect; urbanization was eating into agricultural land and woodlands; industrial expansion was causing increased pollution and loss of fresh water resources. Further ahead loomed the threat of the loss of biodiversity. Addressing these problems, the Commission's report, often referred to as the Brundtland Report, advocated a policy of sustainable development, whereby current demands could be met without prejudice to the legitimate demands of future generations.

The Brundtland Report became the charter document for the "Earth Summit", the United Nations Conference on Environment and Development held in Rio de Janeiro in 1992. One of the most important things to come out of this conference was the Rio Declaration, which set forth guidelines for the future environmental policy of United Nations Member States. One key element in this was the recommendation that, in order to protect the environment, nations should apply the "precautionary principle", which may be summarized as follows: Whenever there is a threat of serious or irreversible damage, lack of absolute scientific certainty shall not be used as an argument for delaying cost-effective measures to prevent the destruction or degradation of the environment. Never precisely defined, this principle is open to different legal interpretations and raises problems about uncertainty and actual risks.

The Brent Spar controversy

The story of the Brent Spar oil rig provides an object lesson in the complexities of applying the precautionary principle in practice. The Shell oil company wanted to get rid of this platform, which had served its useful life in the North Sea oilfields, by sinking it at a suitable spot in the Atlantic. The environmentalist movement Greenpeace successfully campaigned to persuade the public - and hence the politicians - that this would present an unacceptable environmental risk. Shell claimed the opposite but was not believed, and the platform was towed to a Norwegian fjord, where it still awaits its fate.

With the benefit of hindsight, it seems that the risk analysis carried out by Shell was correct and that the Greenpeace assessment was based on inaccurate data. This does not necessarily mean, however, that the platform can safely be disposed of at sea. Scientific risk analysis is only part of the story: there are strongly held emotional convictions about the purity of the sea and opposition to its becoming a rubbish dump. As a basis for action, risk analysis needs to take account of all aspects of a case.

In the Brent Spar case, the decisive issue was whether sinking the platform at sea would lead to serious or irreversible environmental damage. As in many environmental conflicts, the debate was adversarial in form, which is usual in normative and legal contexts but has hitherto been unusual in scientific arguments over issues of "scientific certainty". Does this mean that in environmental issues we are confusing questions of fact with matters of opinion? Should Shell and Greenpeace have got together to conduct a dispassionate enquiry about scientific laws and facts before embarking, if necessary, on a discussion of the pros and cons of possible action? Can factual knowledge be separated from the question of how that knowledge is used?

A positive answer to the latter question presupposes that scientific laws exist and that scientific certainty can be established, at least within acceptable error limits, which has been the received view of science and technology. From Newton's classical mechanics to Einstein's relativity and up to the time of Bohr's quantum mechanics, the laws of nature were expressed in the language of linear mathematics, and the future was computable.