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The Precautionary Principle in Contemporary Environmental Policy and Politics

Andrew Jordan and Timothy O'Riordan

Paper prepared for the Wingspread Conference on 'Implementing the Precautionary Principle', 23-25 January 1998, Racine, Wisconsin

Correspondence address: CSERGE, School of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ, UK

email: a.jordan@uea.ac.uk/t.oriordan@uea.ac.uk; tel: 44 (0)1603 593176; fax: 44 (0)1603 593739

Introduction

This paper tries to place the precautionary principle into some sort of historical and institutional perspective, by outlining its history and current status in national and international environmental policy. Arguably, we need to know about the genesis of the principle before considering how to improve its application in the future. To this end, Section II discusses the origins of the principle in the environmental policy of the former West Germany. Section III outlines seven 'core' elements of precautionary thinking, while Section IV discusses the extent to which they find expression in contemporary environmental policy. The final section begins the process of considering how to improve existing tools of decision making to incorporate precautionary thinking. But, paradoxically, we conclude that precaution will remain politically potent so long as it continues to be tantalisingly ill-defined and imperfectly translatable into codes of conduct, whilst capturing the emotions of misgiving and guilt.

The modern environmental movement proceeds by capturing ideas and transforming them into principles, guidelines and points of leverage. Sustainability is one such idea, now being reinterpreted and implemented in the aftermath of the Rio conference. So too is the precautionary principle. Like sustainability, it is neither a well defined nor a stable concept. Rather, it has become the repository for a jumble of adventurous beliefs that challenge the status quo of political power, ideology and environmental rights. Neither concept has much coherence other than it is captured by the spirit that is challenging the authority of science, the hegemony of cost benefit analysis, the powerlessness of victims of environmental abuse, and the unimplemented ethics of intrinsic natural rights and inter-generational equity. It is because the mood of the times needs an organising idea that the precautionary principle is getting a fair wind.

To avoid the sustainability concept becoming meaningless, Norton (1992, 98) calls for:

"a set of principles, derivable from a core idea of sustainability, but sufficiently specific to provide significant guidance in day to day decisions and in policy choices affecting the environment."

Precaution is one such principle, for it provides an intuitively simple to ensuring that human intervention in environmental systems is made less damaging. Admittedly, precaution lacks a specific definition and, as yet, it cannot prescribe specific actions or solve the kind of moral, ethical and economic dilemmas which are part and parcel of the modern environmental condition. Nonetheless, the precautionary principle has much efficacy because it captures an underlying misgiving over the growing technicalities of environmental management at the expense of ethics and open dialogue; of environmental rights in the face of vulnerability; and of the manipulation of cost-benefit analysis by powerful vested interests supporting development. Paradoxically, as precaution becomes increasingly integrated into modern environmentalism it may well run the risk of following the dangerously successful pathway pioneered by sustainability. We say 'dangerously successful' because it is precisely the uncritical accumulation of meanings, often contradictory and impractical, that have characterised the success of the sustainability notion in recent years, blunting its uncomfortable message that the existing trajectory of development is socially and environmentally unsustainable.

To date, precaution provides few, if any operable guidelines for policy makers nor does it constitute a rigorous analytical schema. Yet, it is accepted by many national governments and supra-national entities such as the United Nations (UN) and the European Union (EU) for example, as a guiding principle of policy making. It is found in the climate convention and the Rio Declaration. In a nutshell, precaution challenges the established scientific method; it tests the application of cost benefit analysis in the those areas where it is undoubtedly weakest (i.e. situations where environmental damage may be irreversible or potentially catastrophic); it calls for changes to established legal principles and practices such as liability, compensation and burden of proof; and it challenges politicians to begin thinking through longer time frames than the next election or the immediate economic recession. Precaution challenges the existing organisation of academic research because it cuts across disciplinary boundaries and raises issues about the quality of life for future generations. It is profoundly radical and potentially very unpopular.

The History of the Precautionary Principle

The precautionary principle emerged during the 1970s in the former West Germany at a time of social democratic planning. At the core of early conceptions of precaution (or vorsorge) was the belief that the state should seek to avoid environmental damage by careful forward planning. The word vorsorge means 'foresight' or taking care, although it also incorporates notions of good husbandry and 'best practice' in environmental management even in the absence of risk (von Moltke, 1988). There is and has never been an agreed statement about the meaning. As Weale (1992, 79) points out, one respected German commentator has identified at least eleven separate meanings! The vorsorgeprinzip (precautionary principle) was used by the German government in the early 1980s to justify the implementation of vigorous policies to tackle acid rain, global warming and pollution of the North Sea. In the process of standard setting, vorsorge translates into a requirement, placed on operators of industrial processes, to adopt the best available abatement technology in order to minimise polluting emissions at source.

It is important to understand the context in which precautionary thinking first developed. For Hajer (1995) and Weale (1992; 1993), vorsorge is part of a wider set of ideas or an 'ideology' which they label 'ecological modernisation'. This is still a vague notion, but like Brundtland it suggests that the relationship between environmental protection and development is not necessarily antagonistic but potentially synergistic. In fact, the Germans considered precaution a positive facilitator of economic growth rather than a brake upon it; in other words, environmental standards are an opportunity for rather a constraint upon growth. High standards of environmental protection were seen to have the potential to spur the development of green technologies, reduce wastage and meet the demands of a more environmentally aware public. Remember that this was a time of unprecedented concern for environmental damage, particularly to natural forests which the Germans hold very dear to their hearts. Significantly, the notion of ecological modernisation fitted with the dominant path of post-war development in Germany, that of exporting of goods and services of a high technological content. The 'technology forcing' capacity of progressive environmental standards has served Germany well since the 1970s, encouraging the development of a lucrative clean technology sector which now employs 320,000 people (OECD, 1992). Both Weale and Hajer show, however, that the precautionary discourse found a less favourable hearing in countries like the UK, which have a more secretive and consensual style of environmental management, and an institutionalised preference for externalising waste using long pipes and tall chimneys to make the optimal use of the waste assimilative capacity of the environment.

Initially, precaution was by German authorities used in the early 1980s to justify the unilateral application of technology based standards to reduce acid rain. But once in place, the Germans pressed the EU to adopt similar standards across the rest of Europe, to prevent its own industries being placed at a competitive disadvantage (Weale, 1998). This was not enlightened environmentalism at work but the dictates of a competitive market of member states. According to Weale (1998):

"the policy debate was more dominated by competitive considerations rather than environmental concerns, as much of the delay [in adopting measures] was due to fears about comparative costs and benefits of individual states."

In fact, negotiation of the Large Combustion Plant Directive dragged on for nearly five years, but the Germany's conversion to green thinking catalysed a transition in EU environmental policy from reactive policy making to proactive environmental management that endures today. It is encapsulated in landmark documents like the 1992 Fifth Environmental Action Programme and is at work in the EU's progressive position on climate change. As Boehmer-Christiansen (1994: 30) notes in a comprehensive review of the German experience:

"the precautionary principle therefore helped to lay the conceptual and legal basis for a proactive environmental policy, which, once spread into Europe, was also directed at ensuring "burden sharing" in order that German industry would not lose its competitive edge, but rather gain new markets for its environment-friendly technology and products."

Since then, the precautionary principle has entered into the lexicon of modern environmentalism with remarkable speed and stealth. Nowadays, it appears regularly in national legislation, in international statements of policy and in the texts of international conventions and protocols. More recently, it has been adopted as a guiding principle of environmental policy in both the European Union (EU) and the United Kingdom (UK), and it makes an appearance in the 1992 Rio Declaration- a statement of principles and general obligations to guide the international community towards actions that promote more environmentally sustainable forms of development.

However, the precautionary principle still has neither a commonly agreed definition nor a set of criteria to guide its implementation. "There is", Freestone (1991, 30) cogently observes, "a certain paradox in the widespread and rapid adoption of the precautionary principle": while it is applauded as a 'good thing', no one is quite sure about what it really means, or how it might be implemented. Advocates foresee precaution developing into "the fundamental principle of environmental protection policy at [all] scales" (Cameron and Abouchar, 1991, 27). Sceptics, however, claim its popularity derives from its vagueness; that it fails to bind anyone to anything or resolve any of the deep dilemmas which characterise modern environmental policy making. There are legal scholars, for example, who consider precaution to be too blunt an instrument to act as a regulatory standard or principle of law. Bodansky (1991, 5), for example, is highly suspicious of the precautionary principle because it "does not specify how much caution should be taken" in any situation. It cannot, for example, determine what is an acceptable margin of error or what exact threshold of risk warrants the application of precautionary actions. Nor can it determine when precautionary measures should be taken, or define the point at which abatement costs become socially or environmentally 'excessive' (ibid, 5). Initially, German politicians used it to justify policies that already had high public appeal. In a review of German policy, Boehmer-Christiansen (1994) concludes that it has "little meaning other that of enabling the policy process to attempt environmentally more ambitious solutions"; Bodansky (1991, 5) suggests that it constitutes little more than "a general approach to environmental issues."

The emergence of the principle has also engendered a very lively debate among scientists and sociologists of science. In the former camp we have writers like Gray (1990), who deny the principle any role in scientific research, "since by definition it does not have to rely on scientific evidence!" He believes that it is, at best, an "environmental philosophy" - purely a matter for administrators and lawyers rather than scientists seeking "objective scientific evidence." This view is not, however, shared by critics of reductionist science (Johnston and Simmonds, 1990; Wynne and Mayer, 1993).

Core Elements of Precautionary Thinking

So what does the precautionary principle actually mean? At its core lies the intuitively simple idea that decision makers should act in advance of scientific certainty to protect the environment (and with it the well-being interests of future generations) from incurring harm. It demands that humans take care for themselves, their descendants and for the life-preserving processes that nurture their existence. In essence, it requires that risk avoidance becomes an established decision norm where there is reasonable uncertainty regarding possible environmental damage or social deprivation arising out of a proposed course of action. As was indicated in the 1990 Bergen Conference on Sustainable Development, "it is better to be roughly right in due time, bearing in mind the consequences of being very wrong, than to be precisely right too late" (N.A.V.F., 1990, 6). The environment should not be expected to signal pain on being hurt; it is up to humanity, as a matter of moral principle, to recognise that pain might be imposed and to adopt appropriate avoidance (precautionary) measures.

This in turn suggests that any action likely to result in serious environmental harm is morally wrong so should be excluded as a option against which other courses of action are to be compared. Thus a development project that might remove a particularly critical component of life support, say a protective coral reef, simply should not be put up as an option for alternatives to be costed against it. 'Critical' natural habitats such as ancient woodlands, unique wetlands or other features of the landscape that are judged to be historically, aesthetically or intrinsically valuable, should be left intact. There are strong links here with notions of 'inviolability' and of "sustainability constraints" (Jacobs, 1991) and, ultimately, social and environmental limits to conventional notions of economic growth. In effect, this means that humans must learn to widen the assimilative capacity of natural systems by deliberately 'holding back' from unnecessary and environmentally unsustainable resource use on the grounds that exploitation may prove to be counterproductive, excessively costly or unfair to future generations. It should be clear from the foregoing that the application of the precautionary principle can be both ethically and politically contentious.

From the complex, and at times confusing, debate on the meaning and applicability of the precautionary principle it is possible to abstract a number of commonly occurring themes. These are: a willingness to take action in advance of formal justification of proof; proportionality of response; a preparedness to provide ecological space and margins for error; a recognition of the well being interests of non-human entities; a shift in the onus of proof on to those who propose change; a greater concern for dysgenic impacts on future generations; a recognition of the need to address ecological 'debts'. By no means are all these dimensions formally approved of in existing law and common practice. Indeed, the precautionary principle will always be slightly protean because it is evolving through distinct pathways, at different rates in different countries.

• Pro-action: A willingness to take action in advance of scientific proof of evidence on the grounds that further delay may prove to be ultimately more costly to society and nature. Precaution is not simply the prevention of manifest or predicted risks that have been scientifically proven. Rather, the precautionary principle goes beyond the notion of prevention in the sense that it insists that policy makers move to anticipate problems before they arise or before scientific proof of harm is established. In practice, the line differentiating precautionary measures from preventative actions may be very blurred given science's inability to 'prove' anything. This is the zone of 'trans-science' (Weinberg, 1985) which covers matters that are raised by science but cannot be satisfactorily resolved by scientists alone.

Be that as it may, a very strong formulation of precaution demands that all risks to the environment are minimised; that emissions are reduced as low as possible, and that important (or 'keystone') ecological assets and processes are maintained intact. Environmental groups like Greenpeace, for example, go as far as to say that "the precautionary principle calls for the prohibition of the release of substances which might cause harm to the environment even if insufficient or inadequate proof exists regarding the causal link" (emphasis added) (Horsman, 1992, 76). This 'strong' conception offers scientific judgements a very limited role in decision making. However, in reality, precaution is often linked to some consideration of risks, financial costs and benefits. In Germany, for example, the application of precaution is tempered by two other general principles of law: proportionality of administrative action and avoidance of excessive costs (Von Moltke, 1988, 68).

Although the principle of precaution does not state how these different factors should be traded off, it strongly suggests that a strenuous search be conducted for alternative modes of development which minimise discharges and waste products, regardless of whether they are known to have harmful effects, on the basis that prevention is often, though not always, more cost effective than cure. In general, though, the closer controls are placed to the source of the emission and the earlier environmental considerations are factored in to decision making, the more precautionary the overall trajectory of development will be;

• Cost-effectiveness of action: Or proportionality of response to show that there should be a regular examination of the identifiable social and environmental gains arising from a course of action that justifies the costs. The application of proportionality of response is designed to show that there should be a regular examination of identifiable social and environmental gains arising from a cause of action that justifies the costs. Economists emphasise a very strict interpretation of the precautionary principle may be very costly to implement especially if the benefits foregone are appreciable and new information reveals that the measures were in fact unwarranted. Economists say that it is possible to differentiate between actions taken on a precautionary basis (on the strictest interpretation this would equate with zero emissions) and the 'optimal' level of pollution elucidated by a full risk-benefit or cost-benefit analysis. The difference between the two would represent the social opportunity cost of adopting a precautionary perspective.

Potentially, the net social cost of adopting precautionary measures could be extremely large, especially if the adverse environmental impacts turn out to be less important than predicted. However, cost-benefit analyses presuppose good scientific understanding and sufficient time to undertake them - factors which cannot always be relied upon. This sets up an interesting ethical conundrum. If a possible outcome is potentially destabilising to the natural order or to social equity, can it truly be regarded as a realistic option to the point where lost 'benefits' ought to constitute a 'sacrifice'? This is the kind of dilemma referred to by Redclift (1993) when he discusses the distortions inherent in seeking to place a monetary yardstick on what essentially are ethical judgements (see also: O'Riordan, 1997).

Clearly, there is no easy way of integrating risk, financial considerations and highly uncertain science in to decision-making with the appropriate degree of timeliness. Nor does the precautionary principle provide a rigorous mechanism for balancing these disparate factors. Environmental economists believe that the realistic course of action is to insist that standard techniques of cost-benefit analysis incorporate the wider social and environmental costs of development. Then, the presumption should be in favour of high environmental quality (e.g. development should only be allowed when the benefits of acting are much greater than (rather than simply greater than or equal to) the associated costs) (Pearce, 1994);

• Safeguarding ecological space: The precautionary principle insists that the overall capacity of environmental systems to act as a buffer for human well-being must be adequately protected: "any error in risk calculation should be to the advantage of the environment" (Bodansky, 1991, 5). This entails leaving a sufficiently wide natural cushion in the functional equilibria of natural systems. In effect, this means that humans must learn to widen the assimilative capacity of natural systems by deliberately holding back from unnecessary and environmentally unsustainable resource use on the grounds that exploitation may prove to be counterproductive, excessively costly or simply unfair to future generations. Nature's assimilative capacity cannot always be taken for granted- often, we simply do not know enough about the chaotic behaviour of natural systems, to be able to identify 'critical thresholds' (points beyond which irreversible phase changes may occur, possibly culminating in the collapse of ecosystems) with any degree of certainty (McGarvin, 1994; Stebbing, 1992).

In more concrete policy terms, the precautionary principle offers an explicit challenge to the so-called 'dilute and disperse' paradigm (GESAMP, 1986), which has underpinned standard standards in the UK for over a century. The paradigm is built upon the assumption that science can determine the ability of an ecosystem to assimilate hazardous substances without incurring long term damage, and that individual emission permits can be tailored consonant with these 'safe' margins. The precautionary 'paradigm' is based on the denial of the general validity of these assumptions i.e. that science does not always provide the insights with the necessary degree of timeliness or accuracy, and that preventing emissions is often, though not always, a better course of action than restoration of damage once it has occurred;

• Intrinsic value and legitimate status: The stronger formulations of the precautionary principle are consistent with what philosophers term a 'bioethic'. This states that vulnerable, or critical natural systems, namely those close to thresholds, or whose existence is vital for natural regeneration, should be protected as a matter of moral right. This in turn places a strain both on the application of cost-benefit analysis generally, including the proportionality rule, and the normal practice of considering all options as comparators for decision making. Thus, precaution goes to the heart of the philosophical and political debate on the proper relationship between humans and the non-human ('natural') world. In promoting a more humble and less rapacious attitude to the environment, the precautionary principle presents a profound challenge to some of the unstated assumptions of 'modern' (and particularly western) societies: material growth, the power and efficacy of scientific reason and the pre-eminence of human interests over those of other entities. The human race is a colonising species without an institutional or intellectual capacity for equilibrium, and notions of 'care', 'precaution' and 'restraint' strike at the very heart of its common purpose (Jordan and O'Riordan, 1993). The precautionary principle lends strength to the notion that natural systems have intrinsic rights and a non-instrumental value that should be accounted for in decision making.

Unfortunately, the precautionary principle does not state how much environmental quality should be sacrificed for material growth, nor does it determine how a 'non-instrumental' respect for nature should be incorporated into decision making. However, it does offer a strong presumption in favour of high environmental protection and a justification for treating certain environmental functions or features as inviolable. This is a prospect that usually causes alarm amongst those who believe that such a concept is an excuse for deep ecology to ride roughshod over 'sensible' forms of development or impose 'limits' to material growth. The US lawyer Christopher Stone (1987) has sought to allay these fears by indicating that a creative partnership in law can be established to allow nature rights of existence that are not absolute, but require careful deliberation before being set aside;

• Shifting the onus of proof: The precautionary principle suggests that the burden of proof could shift onto the proto-developer to show "no reasonable environmental harm" to such sites or processes, before development of any kind could proceed. This is the reversal of the normal position where it is up to the would-be developer to show likely and unreasonable harm (Cameron and Wade-Gery, 1991). Such a reversal of the liability rule would be truly radical and difficult to implement since it would involve some definition of 'harmfulness' (or if the burden is to be reversed completely, some measure of 'harmlessness').

Traditionally, the law has tended to privilege parties accused of degrading the environment rather than the victims of pollution (i.e. those that are forced to bear the external costs). In general, claims for damage in the law are only upheld if the victim can prove that the emission (or the damage) was reasonably 'foreseeable'. 'Acts of god' and 'accidents' tend to disallow claims for compensation. In this sense, the law offers little inducement to developers or operators of industrial processes to take adequate precautions with regard to the environmental impact of their actions. The introduction of a strict liability regime, on the other hand, would only require the victim to prove that the polluter failed to act with 'due diligence' to gain compensation; in the case of absolute liability, the victim would merely need to prove that damage had occurred to gain financial restitution. More stringent still, would be to reverse the burden of proof entirely (i.e. the burden of proof is placed upon the proto-polluter to prove that emissions are 'harmless' before the activity is sanctioned) as in the licensing of new medicines. But this presupposes some measurement of 'harmlessness', which is sometimes as equally as difficult to prove as 'harmfulness'.

Finally, reversing the burden of proof entirely would be extremely radical, since it would impose an explicit and legally binding 'duty of care' on those who propose to alter the status quo. Admittedly, this raises profound questions over the degree of freedom to take calculated risks, to innovate, and to compensate for possible losses by building in ameliorative measures. Yet, UK and EU law is already moving in this direction with the introduction of formal duties of care, set against the backdrop of a broader, but intensifying, debate on the possible extension of strict liability for environmental damage, no matter how anticipated;

• Meso-term planning: The application of precaution extends the scope of environmental policy from certain and known problems that occur in the present, to future and more uncertain issues. Precaution urges politicians to act with due care and diligence- to anticipate and against problems before they occur. Precautionary actions could be considered as an investment (or insurance) against unforeseen mishaps, or the acceptance of higher costs now in order to guard against dysgenic impacts. But it also implies committing current resources to investments for the future, the benefits of which may be uncertain or at worse non-existent. Since conclusive scientific evidence of harm or excessive damage in the future may not always be available to justify the commitment of resources to precautionary investments, other grounds for legitimation may need to be present, namely moral, political, ethical and legal. Cost benefit analyses rarely take into account the likely costs and benefits of various courses of action during this period. Similarly, legal rules for compensation or obligation to take care are still ill-developed. Needless to say, democracy itself is poorly suited to this time-scale with its heavy political biases in favour of immediate gratification and gain today rather than tomorrow. Here is an arena where the precautionary principle challenges institutional performance and the sense of citizenship which primarily concentrates on the well-being of society today rather than the state of the world in the future;

• Paying for ecological debt: Precaution is essentially forward looking, but there is a case for considering a burden-sharing responsibility for those not being cautious or caring in the past. This is a difficult matter. Responsibility for actions taken in ignorance, or in a climate of opinion that did not regard environmental vulnerability as a serious basis for evaluating options, should not reasonably be placed on those for whom there was no clearly defined duty of taking moral legal care. Nevertheless, shouldering the burden is an important component of precaution. For instance, the notion of common but differentiated responsibility enshrined in the UN Framework Convention on Climate Change, and the concept of conducting precaution 'according to capabilities' in Principle 15 of the Rio Declaration, reflect an embryonic version of these ideas. Despite all this, 'precaution in reverse', while attractive from a moralist or environmentalist viewpoint, could well founder in the courts. Its future, therefore, lies in the political realm.

Putting Precaution into Perspective

Two points should be apparent from the foregoing. First, each of the seven elements requires an institutional mechanism or to make it operational. These could be legal (e.g. the introduction of strict liability regimes), economic (i.e. appropriately weighted cost-benefit analyses with citizens juries to consider especially controversial matters), or technological (e.g. clean production).

Second, precaution works through a continuum within each distinct element. So, there are quite 'weak' formulations that are relatively protective of the status quo through to very 'strong' formulations that predicate the need for much greater social and institutional change. There are, of course, a host of variations in between these poles. The weaker formulations, for example, tend to be restricted to the most toxic and human life threatening substances or activities. They advocate a role for biased cost-benefit analysis, incorporate some concern for technical feasibility and economic efficiency arguments and tend to emphasise the importance of basing judgements on the dictates of 'sound science'. These are very much the concerns of the 'lighter' greens. The following, a statement from the UK government, prescribes a particularly limited role for precaution:

"Where there are significant risks of damage to the environment, [we] will be prepared to take precautionary action to limit the use of potentially dangerous materials or the spread of potentially dangerous pollutants, even where scientific knowledge is not conclusive, if the balance of likely costs and benefits justifies it. The precautionary principle applies particularly where there are good grounds for judging either that action taken promptly at comparatively low cost may avoid more costly damage later, or that irreversible effects may follow if action is delayed" (emphasis added) (HM. Govt, 1990, 11).

The stronger formulations, on the other hand, have more in common with the 'deep green' world-view and ecologism although few political analysts have actually made that link. Dobson (1990, 205), for example, notes that precaution is normally associated with 'deep' greenism ("ecologism"):

"ecologism asks that the onus of justification be shifted from those who counsel as little interference as possible with the non-human world, to those who believe that interference is essentially non-problematic."

In the policy domain, examples of strong formulations are more difficult to find. The Third Ministerial Declaration on the North Sea signed by various North Sea states in 1990, for example, states that governments should:

"apply the precautionary principle, that is to take action to avoid potentially damaging impacts of [toxic] substances... even where there is no scientific evidence to prove a causal link between emissions and effects. (emphasis added).

On this conception, science plays little or no role in policy making; administrators undertake to go beyond science to address known, but still uncertain, threats to the environment. This interpretation is both promoted by and finds support within environmental pressure groups which challenge the legitimacy of science, such as Greenpeace (Horsman, 1992). The Germans tend also to adopt a fairly strong definition of precaution. Boehmer-Christiansen (1994) for example, quotes the following from a 1984 German Federal Government report on air quality:

"The principle of precaution commands that the damages done to the natural world.... should be avoided in advance and in accordance with opportunity and possibility. [Precaution] further means the early detection of dangers to health and environment by comprehensive, synchronised... research... [I]t also means acting when conclusively ascertained understandings by science is not yet available" (emphasis added).

Norton's admonition, namely that meta-concepts must be brought to the heel of pragmatic guidelines, codes of practice and organising principles for regulation and valuation, is most apt. The difficulty facing the adherents of precaution is that there is no agreement over how serious the predicament is. At the root of this dilemma lies contrasting positions on the robustness of natural systems to withstand shock, the seemingly bountiful adaptiveness of human societies to cope with change of whatever kind, and the apparently inherent unwillingness to attach much importance to what may or may not happen beyond one's lifetime.

Actual proof of this shift of emphasis remains elusive. The well known techniques of risk analysis and environmental impact assessment are supposed to convey this role. In practice this is not the case, because few policy-analytical arrangements have incorporated the conditions of "adaptive environmental assessment" associated with C.S Holling and colleagues (1978), or of participatory (or "civic") science promoted by Lee (1993). Both those contributions bemoan the lack of an adequate institutional arrangement to disentangle the unknown, and instead advocate cautious experimentation, seeking to engender interest group support and participation from the 'bottom up'. Both also caution against the use of evaluative procedures that do not explicitly take into account the transitivity and surprise element of ecological and social change in the face of abrupt adjustments.

Despite the admonitions of both Norton and Redclift that economists do not value irreplaceable life support functions in an appropriate manner, environmental and ecological economists are beginning to re-define sustainability in terms of the resilience, criticality and vulnerability of natural systems. Turner (1993), for example, identifies four interpretations of sustainability:

• Very weak sustainability: Assumes no change in aggregate capital stock, but infinite scope for substitution between natural resources and environmental protective systems, and artificial substitutes, human ingenuity and adaptability.

• Weak sustainability: Accepts that some life support systems, habitats, and human artefacts are important for survival and human well-being and should be preserved. This block of assets is referred to as "critical" natural capital. In the weak mode, since capital would largely be confined to key life support processes or elements, such as stratospheric ozone and a large proportion of tropical forests. This class of natural resources and processes therefore deserve protection, signalled by a mix of prices and regulatory safeguards. Here, the notion of precaution as providing 'ecological space' has more meaning, while the benefits of protection are boosted by high social valuation.

• Strong sustainability: adds more weight to both critical natural resource protection and enhancement, greater use of assimilative capacity and environmental carrying capacity modelling for policy, pricing and planning, and widespread adoption of the 'critical load' approach to determining tolerable levels of pollution. Here, the notion of criticality would be extended to heritage, via biodiversity indicators (where these can be determined) and to socially valued landscapes and historical features (as revealed by political pressure). This valuation procedure is never satisfactorily justified, nor is the scientific basis of ecological significance.

• Very strong sustainability: takes more of a deep ecology or Gaian viewpoint, familiar to readers of this journal, through which the intrinsic value of natural objects is given prominence, as is the humility of humanity in managing earthly resources.

Putting Precaution Into Practice: Re-assessing The Role Of Cost-Benefit Analysis

The principle of cost-benefit analysis is to determine whether a proposed investment will provide value for money, and at what point in terms of scale of costs the additional gains that accrue equal the additional expenditure. As is well known, the basis for such calculations assumes not only that some actual or computational value can be placed on the cost-benefit stream, but that the future flow of gains and losses should be equated at the point of analysis through discounting to present values. Extended cost-benefit analysis therefore not only employs imaginative techniques of non-market valuation; it will also be aware of the appropriate discount rate (Pearce, 1993).

In the precautionary mode, however, the benefit stream is problematic. In many cases it cannot be computed even within bounds of probability estimates, for the very act of determining probability is unreliable. This is the case, for example, with estimating the damage associated with climate warming or biodiversity losses. Both the likelihood of the global change, and the possible "costs" are simply not known for sure. Because too, the likely consequences are in the meso-scale, discounting is relatively ineffective as a tool. Thus the actual benefits from avoidance action now depend very much on the shape of the damage curve 50 to 100 years from now.

Analysts will tend to visualise the significance of such a curve on the basis of how resilience or vulnerability is perceived in the capacity of the Earth's life support systems to adjust. Also critical is the degree to which human society can adjust. Resilience or vulnerability therefore applies both to the adaptive capabilities of both natural and human systems. The more the bias is towards vulnerability the more the precautionary principle will be invoked. This will cause the cost benefit analysis to be skewed in favour of costs now over delay, on the grounds that the benefits of early, prudent action will justify this investment. Naturally those whose bias is towards resilience will adopt the opposite view. There early prudent action would be regarded as an unnecessary cost. So for the 'vulnerability perceivers', cost-benefit analysis is loaded in favour of high costs to reputedly but unproven high benefits, while for the 'resilience perceivers' the benefits of early avoidance would have to be made more clearly justified. Any cost benefit decision rule therefore is likely to be intensely political , not purely financial. Equally significant however is the manner in which cost-benefit analyses are to be construed in the light of the precautionary principle. Figure 2 provides a useful guide.

[Figure 2: Precaution and the principle of proportionality]

Again the dimension of interest is the perception of natural resilience. This is a slightly more comprehensive version of the inconvenience to catastrophe theme suggested by Norton (1992, 10). On the horizontal axis is some notion of degree of vulnerability or resilience running from left to right in terms of greater resilience. The vertical axis represents the cost of action.

To the left, we have the strong precaution mode which is evident in the growing resistance to potentially damaging toxic substances, such as organochlorines and volatile organic compounds (VOC's) which persist in the nooks and crannies of all ecosystems, slowly building up chemical 'time bombs'. Bodansky (1994) shows how US statute law is becoming strongly precautionary over the elimination of such substances. The European Union is also in the process of banning a range of chemicals in these categories, and has produced a 'red list' of 23 substances where emissions are to be controlled not just by the very best end of pipe technology, but by fundamental process changes and very strict duties of care and waste handling. Hill (1994, 180-1) and Tait and Levidow (1992) reveal how the release of genetically modified organisms in the UK is being controlled by open peer review that is extremely precautious, with an in-built bias against release or commercial production, except under the most stringent safeguards. In the middle zone of Figure 2, ambivalent precaution would demand the application of the best available technology with only limited safeguards against excessive cost, or uncertain benefits.

Pearce (1994, 149), in line with his reasoning on critical natural capital, accepts that where irreversible margins, or phase-change thresholds are in the offing, given the best scientific knowledge and public support, reliance solely on economic instruments would be inappropriate. This is the zone where risk management depends less on a purely economic calculus than on a social setting of trust and accountability (see: Pidgeon, et al, 1992).

Both these discretionary phrases are meant to provide room for manoeuvre for regulators faced with steadily improving, but costly technology, and dubious gains in terms of immediate or longer term social benefits. The rules of thumb, however, are to err on the side of caution, and the challenge is to provide reasoned scientific evidence to justify a higher than expected cost. This is by no means straightforward, as the legal profession tends to look for the 'certainties' of science as a guide, and may become exasperated when the evidence is uncertain via either ignorance or indeterminacy. As McDonnell (1991, 7) notes:

"arrangements for applying the precautionary principle should include some process of testing scientific reliability. The development of appropriate procedures for this is a large challenge for the future."

Now we come to the most contentious arena of all, namely where precaution is ambivalently applied, because the perception holds that nature can 'take it' or that human adaptation is both purposeful and successful, but where there is growing doubt about the justification of such a proposition. As we have already noted, efforts by economists to calculate the intrinsic social value of critical natural capital (see, for example, Brown and Moran, 1993) and the externality 'adders' associated with electricity production (Pearce, et al, 1992) run into two sets of difficulty: on the one hand, there are critics like Redclift (1993, 16-10) and Sachs (1993: 2) who deride the ideology of converting life support systems into commodities, irrespective of the shaky science. On the other hand, there are the established politicians who look with considerable suspicion on estimates of benefits of avoidance, of say biodiversity loss or future climate warming, which almost by definition produce cost-benefit analysis loaded against long term benefit gains, yet alarmingly loaded towards the present on the cost front. This is an unstable relationship for an embryonic cost-benefit analysis in precautionary clothes, especially during times of economic recession.

Conclusion

The precautionary principle is vague enough to be acknowledged by all governments regardless of how well they protect the environment. But the politics of precaution are also powerful and progressive, since they offer a profound critique of many of the ways in which the environmental policy is currently determined. Wrapped up in the debate about precaution are forceful new ideas which point the way to a more preventative, source-based, integrated and biocentric basis for policy. The point about the precautionary principle is that it swims against the economic, scientific and democratic tides. It requires 'sacrifice' of anyone who cannot see the justification of taking careful avoidance. As we have repeatedly stressed, the strength of the precautionary principle lies in beliefs about social or environmental resilience, and in the capacity of social groups or political systems to respond to crises. Therefore those who support the notion of resilience and accommodation/adaptation would require precautionary 'sacrifice' as a higher level of cost than those who are more ecocentric on such matters.

The emphasis which governments continue to place on 'sound science' and careful cost-benefit analysis, suggest a deep seated suspicion of the threat which it appears to hold to economic growth and 'rational' policy making. Precaution will not explode on to the environmental stage, sweeping away all forms of risk or cost benefit assessment, careful scientific analysis and existing legal norms relating to the relative power of polluters and victims. Rather, it will seep through the pores of decision making institutions and the political consciousness of humanity by stealth. It will do this when, and if, it has the tide of the times behind it.

References

Boehmer-Christiansen, S. 1994 The Precautionary Principle In Germany: Enabling Government. In: T. O'Riordan and J. Cameron (eds) Interpreting the Precautionary Principle. Cameron and May: London.

Bodansky, D., 1991 Scientific Uncertainty And The Precautionary Principle. Environment, 33, 7, 4-5 and 43-45.

Bodansky, D. 1994 The Precautionary Principle: the US experience. In: T. O'Riordan and J. Cameron (eds) Interpreting the Precautionary Principle. Cameron and May: London.

Boulding, K., The Economics Of The Coming Spaceship Earth. In: Jarrett, H., 1966 Environmental Quality In A Growing Economy. John Hopkins University: Baltimore.

Brown, K. and Moran, D. 1994 Valuing Biodiversity: The Scope And Limitations Of Economic Analysis. In: Sanchez, V. and Juma, C., Biodiplomacy. ACTS Press: Nairobi.

Cameron, J. and Abouchar, J., 1991 The Precautionary Principle. Boston College International And Comparative Law Review, 14, 1, 1-27.

Cameron, J., Wade-Gery, W., 1991 Addressing Uncertainty: Law, Policy And The Development Of The Precautionary Principle. CSERGE Working Paper GEC 92-43. CSERGE: UCL and UEA.

Crowards, T. 1997 Non-Use Values and the Environment. Environmental Values, 6, 2, 143-168.

Dobson, A., 1990 Green Political Thought. Harper Collins: London.

Freestone, D., 1991 The Precautionary Principle. In: Churchill, R. and Freestone, D., (eds) International Law And Global Climate Change. Graham and Trotman: London.

GESAMP, 1986 Environmental Capacity: An Approach to Marine Pollution Prevention. FAO Report No. 30. FAO: New York.

Gray, J.S. 1990 Statistics And The Precautionary Principle. Marine Pollution Bulletin, 21, 4, 174-176.

Hajer, M., 1995 The Politics of Environmental Discourse. Clarendon: Oxford.

Hill, J., 1994 Regulating Biotechnology. In: O'Riordan, T. and J., Cameron (eds) Interpreting the Precautionary Principle. London, Cameron and May.

HM. Govt, 1990 This Common Inheritance: Britain's Environmental Strategy. Cmnd 1200. HMSO: London.

Holling, C.S., 1976 Adaptive Environmental Planning And Management. IIASA: Luxembourg.

Horsman, P., 1992 Reduce It; Don't Produce It: The Real Way Forward. In: O'Riordan, T. and Bowers, V., (eds) IPC: A Practical Guide For Managers. IBC Technical Services: London.

Jacobs, M., 1991 The Green Economy. Pluto Press: London.

Johnston, P. and Simmonds, M., 1990 Precautionary Principle. Marine Pollution Bulletin, 21, 12, 402.

Jordan, A.J., O'Riordan, T. 1993, Implementing Sustainable Development: The Political And Institutional Challenge. In: Pearce, D., et al Blueprint Three. Earthscan: London.

Lee, K., 1993 Compass and Gyroscope: The Role Of Science In Environmental Policy Making. Island Press: New York.

McDonnell, G., 1991 Risk Management And The Precautionary Principle: Coping With Decisions. In: Harding, R. and Fisher, L., (eds) The Precautionary Principle. University of New South Wales Press: Sydney.

McGarvin, G., 1994 The Implications Of The Precautionary Principle For Biological Monitoring. In: O'Riordan, T. and Cameron, J., (eds) Interpreting the Precautionary Principle. Cameron and May: London.

N.A.V.F., 1990 Sustainable Development, Science And Policy: The Conference Report. N.A.V.F: Oslo.

Norton, B. 1992 Sustainability, Human Welfare and Ecosystem Health. Environmental Values 1: 97-112.

OECD, 1992 OECD Environmental Performance Reviews: Germany. OECD: Paris.

O'Riordan, T. 1997 Valuation as Revelation and Reconciliation. Environmental Values, 6, 3, 169-184.

Pearce, D., Bann, C. and Georgiou, S., 1992 Social Cost of Fuel Cycles. HMSO: London.

Pearce, D., 1993 Economic Values And The Natural World. Earthscan: London.

Pearce, D. 1994 The Precautionary Principle In Economic Analysis. In: O'Riordan, T., Cameron, J., (eds) Interpreting The Precautionary Principle. Cameron and May: London.

Pidgeon, N., et al, 1992 The Perception Of Risk. In: Royal Society Study Group, Risk: Analysis, Perception, Management. Royal Society: London.

Redclift, M., 1993 Sustainable Development: Needs, Values, Rights. Environmental Values, 2, 3-20.

Sachs, W., (ed) 1993 Global Ecology: A New Arena of Political Conflict. Zed Books: London.

Stebbing, A.R.D. 1992 Environmental Capacity And The Precautionary Principle. Marine Pollution Bulletin, 24, 6, 277-295

Tait, J. and Levidow, L., 1992 Pro-Active and Reactive Approaches To Risk Regulation: The Case Of Biotechnology. Futures, April, 219-231.

Turner, R.K., 1993 Sustainability: Principles And Practice. In: Turner, R.K., (ed) Sustainable Environmental Economics and Management. Belhaven Press: London.

Von Moltke, K., 1988 The Vorsorgeprinzip In West German Environmental Policy. In: Royal Commission On Environmental Pollution, Twelfth Report: Best Practicable Environmental Option. Cmnd 310. HMSO: London.

Stone, C., 1987 The Earth And Other Ethics: The Case for Moral Pluralism. Harper and Row: New York.

Weale, A., 1992 The New Politics Of Pollution. Manchester University Press: London.

Weale, A., 1993 Ecological Modernisation And The Integration Of European Environmental Policy. In: Liefferink, J.D., et al, (eds) European Integration And Environmental Policy. Belhaven Press: London.

Weale, A. (ed.) 1998 European Environmental Governance. Routledge: London (in press).

Weinberg, A.M., 1985 Science And Its Limits. Issues in Science and Technology, 2, 59-72.

Wynne, B., Meyer, S., 1993 How Science Fails The Environment. New Scientist, 5 June, 33-35.