Environmental Ethics is that sub-field of philosophy which seeks to articulate reasons why non-human "nature" — usually writ large to include collective entities like species and ecosystems — has value that cannot be reduced solely to economic value. The central move of most work in environmental ethics has been to argue that there is a need for a "new environmental ethic" that breaks radically with the existing Western traditions of ethical theory. Existing traditions are taken to be anthropocentric in claiming non-human nature to have only "instrumental" value as a means to human well-being. In contrast, a new environmental ethic would hold that nature has "intrinsic" value, or value as an end in itself. (For surveys of this work, see Ouderkirk 1998, Wenz 2000, Light 2002, and Palmer 2003.) However, while there are good reasons for rejecting the claim that the values of non-human nature can be reduced to economic value, there are ample resources within the bounds of traditional Western ethics to call into question this assumption common in the environmental policy process.

Standard policy approaches do tend to assume a particular view of the value of environmental goods. Consider two pressing global environmental problems — climate change and biodiversity loss. Two influential policy responses to these problems are to be found in the Stern Review on climate change and the United Nations initiative on The Economics of Ecosystems and Biodiversity (TEEB). What the Stern review and TEEB share is a particular ethical framework for understanding environmental problems. The Stern Review usefully summarises this framework thus:

The underlying ethics of basic welfare economics, which underpins much of the standard analysis of public policy, focuses on the consequences of policy for the consumption of goods and services by individuals in a community.... In this approach, the objective is to work out the policies that would be set by a decision-maker acting on behalf of the community and whose role it is to improve, or maximise, overall social welfare. (Stern et al. 2006).

On this account the aim of environmental decision making should be to improve or maximise welfare. The failure of market institutions to do this is taken to be a consequence of an absence of prices on greenhouse gas emissions or biodiversity loss. The solution to environmental problems therefore lies in the extension of prices to include those goods, whether through shadow prices that attempt to capture what individuals would pay if there was a market, or through the construction of markets in greenhouse gas emissions and biodiversity and ecosystem services. TEEB shares this approach (TEEB 2010).

The ethical framework that is being invoked here has its roots in utilitarianism. Classical Utilitarianism claims that the right action is the one which brings about the greatest total well-being of affected agents. We can understand the limitations of this view by breaking it down into its three independent components:

1. Welfarism: The only thing that is good in itself and not just a means to another good is the well-being of individuals.

2. Consequentialism: Whether an action is right or wrong is determined solely by its consequences.

3. Maximising of value: One should choose the action that produces the greatest total amount of good.

A number of competing frameworks are to be found in contemporary environmental ethics, and these can be understood, and simply illustrated, in terms of their critical responses to these three components.

1. Welfarism

In classical utilitarianism well-being is understood hedonistically in terms of psychological states — pleasure, and the absence of pain. In modern welfare economics it is understood in terms of the satisfaction of preferences whose strength can be measured by an agent's willingness to pay for marginal changes in goods. The different views have implications for the question of whose well-being should count. Modern welfare economics only includes the preferences of those who can express a willingness to pay for a good — in effect, human beings.

However, the classical utilitarian approach in fact allows for a wider constituency — it includes the welfare of all sentient beings (Singer 1986). It is also possible to extend the concept of well-being beyond sentient beings to include the good of all individual living things (Attfield 1987). This would be a form of biocentrism which counts all life as a locus of moral considerability. Other approaches raise questions about whether welfare is the only thing that is good in itself that should count in a moral sense; they claim collective entities such as species or ecosystems should count independently of the well-being of their members (Callicott 1980). Such positions are often called ecocentric (or holistic forms of nonanthropocentrism). The different perspectives have different implications for conservation policy. For example, biocentric and ecocentric positions might justify the culling of animals in a way that would not be justified from the view that only sentient beings count. They also suggest different understandings of the nature of the threats posed by climate change and biodiversity loss.

Another response again might be to argue that the understanding of well-being in terms of psychological states or the satisfaction of preferences should be rejected. Human well-being or flourishing should be understood objectively in terms of the realization of particular goods and states of affairs such as autonomy, accomplishment, having close personal relationships, and so on. One virtue of this approach is that it allows that concern for the non-human world for its own sake might be constitutive of a good human life (O'Neill 1993).

2. Consequentialism

One objection to consequentialism is to argue that certain actions are wrong even though they lead to the best outcomes. From what is called a "deontological" perspective, conseqentialism permits too much: it would be wrong to torture the child of a terrorist to force her to divulge where a bomb has been hidden, even if this yields a better outcome. The basic ethical question is not "what act produces the best outcomes?" but rather "what acts am I obliged to perform or not perform?"

What reasons might be offered for deontological constraints? One answer is that individuals have a moral standing which cannot be over-ridden for the purposes of promoting the greater good. The 18th century philosopher Immanuel Kant, for example, claims that certain beings are ends in themselves who cannot be treated merely as a means, but argues that this applies only to persons capable of rationally choosing their own ends (Kant 1956). One expression of this view is to say that individuals have rights which cannot be overridden for other ends. While there are arguments about whether such fundamental rights exist at all, some environmental ethicists argue that they should be extended to include non-humans. Tom Regan suggests that no sentient being should be treated as a mere "receptacle," since they are a "subject of a life" (Regan 1988). Some, such as Paul Taylor (1986), have argued that all individual living beings should be treated as ends in themselves since they are capable of pursuing their own good. Others such as Holmes Rolston argue that we even have duties to ecosystems (Rolston 1990).

A second response to conseqentialism is to argue that it demands too much of moral agents: one could not, for example, demand of a chemist opposed to chemical weapons that he should take a job on the grounds that if he does not then a zealot for chemical weapons will be appointed which would have worse consequences. The pursuit of consequences might require a person to forsake her integrity and to treat her own projects and commitments as just so many desires to be put into the calculus with others (Williams, 1973).

What justification might be offered for this stance? One answer is to appeal to a virtue ethic. The basic ethical question is not about consequences or permissible acts, but rather about what sort of person I should be. There might be acts one cannot do, because one does not want to be the kind of person that could do them. A virtue ethic also offers a fresh defense of environmental concern (Sandler 2007). On the virtues view we begin with the question of what sort of person we should be. In answer, we specify a certain range of excellences of character that are constitutive of a good human life: integrity, sensitivity, courage, loyalty, good judgment, and so on. Many of these dispositions will determine how we relate to our fellow humans. However, dispositions of character that make for a good human life can also readily embrace dispositions to respond appropriately to beings in the non‑human world: for example, with sensitivity and compassion towards other sentient beings.

3. Maximizing of Value

Is maximising the total aggregate good all that matters? One reason for suggesting not is that maximising the total good fails to capture adequately the distribution of goods and bads. Environmental problems have a strong distributional dimension. For example, the negative effects of climate change will fall disproportionately on the poor in current generations, and on future generations who are less responsible for greenhouse gas emissions as they accrue. Standard economic approaches to policy making tend to exacerbate those problems. Thus, (1) willingness to pay measures of welfare count the welfare of the poorest at a lower value, since the marginal value of a dollar or pound for a poor person is much higher than it is for a richer person; and (2) the practice of discounting future utility means that the well-being of those in the future counts for less than that of those who currently exist. Neither of these follows from classic utilitarianism, which holds that "each is to count for one, and none for more than one." The Stern Review indeed follows the classic position and does not discount future utility as such, although it does discount future consumption. However, for the utilitarian, the distribution of goods has only instrumental value: we should choose that distribution of goods that maximises the total amount of well-being.

It is from this perspective that problems of justice arise. For example, displacing a population in order to build a dam might cause a great deal of misery for the worst off, but if it produces a marginal gain for a larger population who are already well off then, on a utilitarian calculation, the policy is justified provided the population is great enough.

There are a variety of different accounts of justice that might be offered as alternatives to the view that we should distribute goods to maximise total welfare. One is that we should give priority to the worst off; another is that we have a duty to make sure all reach a minimal level of welfare; a third is that justice demands equality in the distribution of welfare or of the goods required for welfare.

A second potential problem for the assumption of maximising aggregate value is that of value commensurability (O'Neill et al. 2008). Does there exist a common measure of value through which different options or states of affairs can be ordered? One answer that is assumed in standard cost-benefit analysis is that a person's willingness to pay at the margin for some good provides a measure of the expected improvement in well-being that she will gain from a good. The proper response to environmental problems on this view is to extend the measuring rod of money to include environmental goods that are currently unpriced. Thus TEEB is attempting to put a price on ecosystem services and biodiversity.

There are a number of objections to this approach. First, some affected parties — future generations and non-human animals — cannot express a willingness to pay. Second, what a person prefers as a private consumer of goods can depart from the values they express as a citizen in public deliberations (Sagoff 1988). Finally, many ethical commitments are constituted by a refusal to put a price on them (Raz 1986, O'Neill 1993, Spash 2008). If I care about something, then one way of expressing that care is by refusing to put a price on it.

These are problems with using money as metric of value. They do not in themselves rule out an alternative common measuring rod of value. Nonetheless there are powerful motivations for a pluralism about environmental value that raise possible problems. The very variety of kinds of values at play in the environmental domain gives reason to pause as to whether they could be brought under a single metric (Light 2009). They seem to raise issues more fit for ethical deliberation than economic calculation. Any view, such as the TEEB synthesis and the Stern Review, or any other analysis of a single metric will likely miss something. The hard question is how to articulate and make sense of the multiple reasons why environments and the human and non-human beings and states they contain matter, and how to make good choices in the light of these reasons.