Badgers, bovine tuberculosis and the role of science in the formulation of Welsh environmental and agricultural policy – Patrick Bishop

To claim that environmental law and environmental policy is heavily, even primarily, science based is too trite an assertion by far.1 The influence of scientific discourse on the environmental movement is unsurprising; it was scientists who first demonstrated the now almost axiomatic link between unregulated human activity and environmental degradation.2 Indeed, it has been suggested that contemporary environmental law should move away from a pluralistic notion of legitimacy to one based primarily on science.3 However, while one cannot deny the importance of science in the context of environmental law and the formulation of environmental policy, a science-led approach is not unproblematic. It is often the case that, implicitly, those who assert that science-led or evidence-based environmental policy is to be lauded subscribe, to a greater or lesser extent, to the notion that science is able to provide an answer to any policy question. Experience teaches us that is not the case; as Ravetz has opined: ‘it [science] now faces a crisis of confidence, of legitimacy and ultimately of power.’4 Scientific evidence is seldom incontestable and, particularly where a scientific study is carried out specifically to inform policy, the results are often, if not invariably, open to interpretation.5 This chapter will primarily draw upon the Welsh Government’s plans to eradicate bovine tuberculosis (hereafter bTB), as a means of analysing the role and influence of science in the formulation of environmental and agricultural policy. In this context, the most pertinent (and controversial) question is the extent to which the culling of badgers (Meles meles) is able to make a significant contribution to the reduction and eventual eradication of bTB. The central objective is an exploration of the extent to which science is able to constrain political choice. From a narrow perspective, science is clearly able to restrict policy formulation in the technical sense that science reveals the parameters of what is possible. This chapter will focus on the broader issue of the influence of science on policy design, particularly in the context of policy makers who openly subscribe to a science-led approach. A discussion of the nature and scale of the problem of bTB will be followed by an evaluation of the scientific evidence in relation to the efficacy of badger culling. The proceeding sections will consider the varied roles of science in informing decision making and the formulation of policy prior to an analysis of the Welsh Government’s use of scientific evidence in the context of bTB.

Bovine tuberculosis: the nature and scale of the problem

Bovine tuberculosis, caused by the bacterium Mycobacterium bovis (M. bovis), has been a persistent problem in UK cattle farming for a considerable time. The disease first gained the attention of the public and policy makers in the late nineteenth century, with widespread concern over the dangers to human health from consuming infected meat.6 In 1934, the Gowland Hopkins Report recognized that infected milk, and not meat, was the dominant source of human infection.7 Since then the widespread use of pasteurization has led to the virtual eradication of bTB in humans.8 Thus, bTB in a contemporary context is predominantly viewed as an animal health problem. Given the costs associated with state-funded compensation for compulsorily slaughtered infected animals (considered below), successive governments have sought to mandate measures with the overall aim of bTB eradication.

The debate about whether badger culling is able to assist in the eradication of bTB is complex and multi-dimensional; the Welsh Assembly’s initial decision to authorize culling has led to the pro-cull and pro-badger factions adopting rather entrenched positions.9 However, there is a loose consensus on both sides of the debate that bTB requires government attention. Thus, it is the efficacy of badger culling, not whether bTB is a significant problem, that is principally at issue. The eradication of bTB, described by the Welsh Assembly Government (as it was then titled) as ‘one of the biggest threats to Cattle farming in Wales’, is an issue of extensive socio-economic importance.10 In 2009, in excess of 11,500 bTB-infected cattle were slaughtered and, since 2000, approximately £120 million has been spent on the payment of compensation to Welsh farmers following the compulsory slaughter of infected animals.11 It is a relatively safe assumption that the true economic cost of bTB extends beyond the publicly funded compensation system. An approximate figure for the cost of the average confirmed herd breakdown is £30,000; of this total figure, £20,000 falls to the state (predominantly in the form of compensation and the cost of testing) and the remainder is borne by the farmer/cattle owner (costs associated with herd movement restrictions, loss of breeding lines etc.).12 As illustrated by a recent survey conducted by the Farm Crisis Network, in addition to the economic costs associated with bTB, the consequences of a confirmed herd breakdown and the resulting destruction of infected animals will often entail a human cost for farmers and their families in terms of concern, anxiety and, in some cases, physical illness exacerbated by stress.13

The preceding discussion has attempted to summarize what may be termed the mainstream view that bTB is a serious problem that necessitates state intervention. However, the economic and social costs highlighted above flow directly from the Welsh Government’s adherence to a test and slaughter policy. The desirability and efficacy of this policy has not gone unquestioned. Given that bTB no longer represents a serious threat to public health (on the assumption that widespread pasteurization of milk continues), Torgerson and Torgerson have argued that, in the absence of any evidence that the current bTB control mechanisms are economically effective in terms of improvements in animal health/welfare and industry profitability/viability, the current programme represents a ‘clear example of misallocation of public resources.’14 Thus, it is argued the current bTB control programme should be abandoned until such time that evidence of a positive cost– benefit ratio exists. The abandonment of the current bTB control policy would unquestionably have ramifications for the UK cattle industry on the basis that EU law prohibits the live export of cattle that have tested positive for bTB.15 Torgerson and Torgerson are rather sanguine in relation to the damage to international trade that would flow from the abandonment of a bTB eradication programme, on the basis that the cost of the policy exceeds the value of live exports from the UK.16 Moreover, it is noted that only 1.4 per cent of the UK cattle population is exported each year.17 While it is generally accepted that the economic value of live cattle exports is relatively modest, it should be noted that such statistics should be analysed in light of the bovine spongiform encephalopathy (BSE) crisis, which totally devastated UK cattle exports.18 However, even if live export levels returned to pre-BSE crisis levels, it would remain difficult to discern a noticeable positive cost–benefit ratio. In the year immediately preceding the BSE crisis (1995), live cattle exports were worth approximately £70 million to the UK economy.19 During 2009 in England alone, the cost of the test and slaughter policy to the tax payer was £63 million.20 As previously noted, from 2000, the policy incurred costs of £120 million in Wales. Thus, even if live export levels fully recovered, it is safe to assume that the costs associated with the current bTB eradication programme would continue to outweigh any benefits in terms of international trade. However, the formulation of a bTB eradication plan is an EU-imposed obligation.21 Thus, a laissez-faire approach is unlikely to be considered a viable option for the foreseeable future. Indeed, the Independent Scientific Group on Cattle TB has accepted the basic premise of the foregoing discussion:

While it continues to be widely accepted that bTB requires state intervention, policy makers will continue to search for the most efficacious solution, which in turn raises the question of the role of badger culling in any bTB eradication programme.

The efficacy of badger culling: the scientific evidence

Despite the explicit reference to ‘bovine’ in bTB, the disease is not limited to cattle and it is widely accepted that a reservoir of M. bovis exists in wildlife, including badgers.23 The suspected link between badgers and bTB was first made in 1971, and since then the efficacy of badger culling has been a widely debated issue.24 It is a cruel irony that the link between bTB and badgers roughly coincided with moves to provide statutory protection.25 While a consensus emerged against the cruel and inhuman practice of badger baiting, the discovery of bTB-infected badgers created a new and arguably greater threat to one of the UK’s most charismatic wild species.

From 1973 to 1997, badger culling was extensively utilized in areas with a high incidence of bTB in cattle; in tandem with this approach, a number of scientific studies were carried out with the aim of investigating a possible link between badgers and the infection of cattle with bTB.26 Despite this a conclusive link between badgers and bTB in cattle remained elusive, as Enticott has noted:

The statistician’s mantra that ‘correlation does not imply causation’ is particularly apt in this context.28 In response to growing concern over the government’s approach to bTB, an independent scientific review was commissioned under the chairmanship of John Krebs. The resulting report concluded that ‘Most of this evidence is indirect, consisting of correlations rather than demonstrations of cause and effect.’29 It was therefore recommended, inter alia, that an expert group should be convened to conduct a randomized culling trial to test the effectiveness of different strategies and to provide unambiguous evidence of the role of badgers in the spread of bTB.

In response to the recommendations of the Krebs report, the UK government assembled an Independent Scientific Group (hereafter ‘ISG’) to oversee a long-term randomized experiment to test the effectiveness of badger culling as a means of controlling bTB.30 The randomized badger-culling trial (hereafter RBCT) spanned a period of nine years (1998–2007) at a cost of approximately £50 million. A close analysis of the methodology employed is beyond the scope of this chapter (and the expertise of the author) and the detailed statistical data produced may be incomprehensible to anyone without scientific training. Nevertheless, the conclusion provided in the final report of the ISG is as simple as it is stark: ‘After careful consideration of all the RBCT and other data presented in this report, including an economic assessment, we conclude that badger culling cannot meaningfully contribute to the future control of cattle TB in Britain.’31 In terms of other options for controlling bTB, the ISG supported further research on the use of cattle- and badger-based vaccination but noted that, given the legal and practical obstacles to the use of vaccination, it should be considered only as a longer-term option.32 Thus, the overall conclusion of the ISG was that the main ‘tool’ in the control and eradication of bTB should be improved cattle-based control measures including, inter alia, more thorough controls on cattle movements, quarantine of purchased cattle and shorter testing intervals.33

The varied roles of science in informing decision making

As previously noted, environmental law and policy is heavily influenced by science; to claim that a legal instrument or policy approach is influenced and guided by science provides an aura of respectability. This is unsurprising; no sensible policy maker would openly subscribe to the formulation of policy based on superstition, conjecture or even anecdote. In sum, for decision makers, a science-led approach represents motherhood and apple pie. However, science and objectivity cannot always be equated; academic literature is replete with assertions that science is a value-laden, socially constructed concept.34 Moreover, Doremus has referred to the ‘truism that environmental policy choices must always be made in the face of significant uncertainties.’35 Despite the commonly held view that science is seldom able to provide definitive, conclusive and indisputable conclusions, policy makers remain wedded, at least ostensibly, to the desirability of adopting a science-led approach to the formulation of policy.

As a matter of linguistic convenience one may talk of ‘science’, but a more appropriate term is ‘sciences’; the extent to which one may make a claim of conclusiveness (or lack thereof) varies with the scientific discipline in question. It is possible to construct a hypothetical spectrum of science, with ‘hard’ science and ‘soft’ science situated at opposite ends. Although the dividing line between ‘hard’ and ‘soft’ sciences is therefore somewhat blurred, the latter is arguably of greatest relevance to environmental law and policy. In the context of environmental policy informed by science, inconclusiveness and contestability are unavoidable, a position succinctly summed up by Ravetz thus: ‘All too often, we must make hard policy decisions where our only scientific inputs are irremediably soft.’36 Stated in a more nuanced manner, the sciences that are of most significance to environmental law may be situated towards the ‘soft’ end of the spectrum: ‘ecology and the related biological sciences will never reach the precision and elegance of physics and mathematics.’37 To make such a claim in no way denigrates such disciplines, as Babich has noted: ‘it takes nothing away from the respect due to scientists working in the field to note that toxicology and epidemiology are still young, fundamentally “soft” sciences.’38

While one may talk in generalized terms of the nature of science and its apparent limitations as a clear guide to the formulation of environmental policy, it is possible to construct a taxonomy that encompasses the full range of scientific methods. To this end a number of commentators have attempted to distinguish what may be termed traditional science (the archetypal white-coat-clad ‘boffin’ engaged in experimentation simply for the acquisition of knowledge and furtherance of understanding) and science conducted specifically to guide and inform policy. A number of terminological innovations seek to illustrate the point: ‘normal’ and ‘post-normal’ science; ‘sound’ and ‘regulatory’ science; and ‘science policy’. Whichever nomenclature is used, such distinctions share common themes; science conducted for the express purpose of informing regulatory policy is often characterized by time and resource constraints and/or the absence of peer review.40 Further, particularly in the area of risk-based standards (e.g. devising a regulatory scheme designed to reduce human exposure to carcinogens), scientific conclusions will often involve a significant element of extrapolation: from high to low dosage levels, from animals to humans, from short-term to long-term exposure.41

The obvious question that flows from the preceding discussion is the extent to which the science conducted for the purpose of determining the efficacy of badger culling as a tool of bTB eradication policy falls into the category of regulatory science. The distinction between traditional and regulatory science is not always easy to draw in a clear-cut manner; thus, the response to such a question is complex. In a narrow sense, the RBCT represents regulatory science on the basis that the experiment was specifically commissioned to inform government policy on bTB. Nevertheless, the RBCT certainly lacks many of the characteristics associated with regulatory science. First, a study spanning nine years and with a budget of £50 million cannot sensibly be classified as an experiment subject to time and resource constraints. Second, in addition to a comprehensive final report, the findings of the RBCT were routinely published in reputable, peer-reviewed journals on an ongoing basis. In terms of the issue of external peer review, a note of caution is necessary: peer review cannot automatically be construed as the sine qua non of scientific rigour, as Doremus has noted:

External peer-review may not represent a panacea but open and transparent scientific discourse may usually be relied upon to reveal a patent lack of objectivity.43 Third, the nature of the RBCT was such that there was no necessity to engage in the extensive extrapolation one associates with science designed to inform risk-based regulation. While any non-scientist, comparatively ignorant of the rigours of the scientific method, should be reluctant to pronounce judgement on the reliability of a scientific endeavour, it seems that one might reasonably conclude that the RBCT may be classified as sound science. Although no doubt cognizant of the dangers of exceeding the boundaries of their area of expertise, the Court of Appeal in Badger Trust v. The Welsh Ministers reached a similar conclusion. Smith LJ noted that the RBCT appeared ‘to have been well conducted and to have provided reliable information.’44

One conclusion that might be gleaned from the foregoing discussion is that any decision to authorize badger culling in Wales is not supported by the scientific evidence and thus any claim of science led policy rings hollow. Yet such a conclusion, however tempting, is bordering on simplistic for the following reason. The results of RBCT did actually demonstrate a reduction in the incidence of bTB. The consultation document produced prior to the enactment of Tuberculosis Eradication (Wales) Order 2009, which authorized the culling of badgers (subsequently quashed by the Court of Appeal in Badger Trust v. The Welsh Ministers), relied heavily on an article published by Jenkins et al. in the International Journal of Infectious Diseases, providing an analysis of the data produced during the RBCT conducted by the ISG.45 The article focused on the use of proactive culling and the potential effects on the incidence of bTB during the post-cull period. Within the trial zone, a 30.2 per cent reduction in bTB was recorded, with an increase in the incidence of bTB outside the culling area of 12.5 per cent (thought to be attributable to the perturbation effect).46 The advice provided to the Welsh Minister by the Chief Veterinary Officer for Wales concluded that Jenkins et al. estimated that twelve herd breakdowns, out of a potential 130, were prevented by the proactive cull, thus providing an overall 9 per cent reduction in herd breakdowns.47

While the scientific evidence highlighted above would have clearly influenced the decision-making process, it did not provide a definitive answer to the question of whether to instigate a badger cull. This is perhaps unsurprising; the view that science cannot address policy questions is commonplace:

Thus, the RBCT was able to provide data that demonstrated a reduction in herd breakdowns in areas subject to proactive culling, but this alone does not answer the policy question of whether culling should be used as a means of tackling bTB. This question is situated at the interface between science, law and policy and the next section views this from the statutory basis chosen for the purposes of the proposed cull.

Legal analysis of badger-culling policy decisions

The Welsh Assembly’s first move towards the utilization of badger culling as a method of bTB control came with the enactment of the Tuberculosis Eradication (Wales) Order 2009.49 Following the Court of Appeal’s decision to quash the order, and a further consultation exercise, the Welsh Assembly passed the Badger (Control Area) (Wales) Order 2011, which authorized the destruction of wild of badgers within an area of Wales referred to as the Intensive Action Pilot Area (IAPA).50 In both instances the Welsh Minister acted pursuant to a power granted by the Animal Health Act 1981. In particular, Section 21 provides that the National Assembly for Wales may issue an order authorizing the destruction of wild animals provided that the two-stage test contained in Section 21(2) is satisfied, namely:

Section 21 does not explicitly require the discretion (as evidenced by the word ‘may’) to be exercised in cognizance of scientific evidence. However, such a requirement may be readily implied. To this end, the questions whether a disease exists among wild animals, whether it is being transmitted to other animals and whether the destruction of wild animals will lead to the elimination or substantial reduction of a disease can be answered only with significant scientific input, a position which has been judicially recognized: