Several philosophers deny that an individual person’s emissions of greenhouse gas do any harm; I call these “individual denialists.” I argue that each individual’s emissions may do harm, and that they certainly do expected harm. I respond to the denialists’ arguments.

We analyze the role of ethical values in the determination of the social cost of carbon, arguing that the familiar debate about discounting is too narrow. Other ethical issues are equally important to computing the social cost of carbon, and we highlight inequality, risk, and population ethics. Although the usual approach, in the economics of cost-benefit analysis for climate policy, is confined to a utilitarian axiology, the methodology of the social cost of carbon is rather flexible and can be expanded (...) to a broader set of social-welfare approaches. [Open access]. (shrink)

_ Source: _Page Count 28 Recent debates over climate change policy have made it clear that the choice of a social discount rate has enormous consequences for the amount of mitigation that will be recommended. The social discount rate determines how future costs are to be compared to present costs. Philosophers, however, have been almost unanimous in endorsing the view that the only acceptable social rate of time preference is zero, a view that, taken literally, has either absurd or extremely (...) radical implications. The first goal of this paper is to show that the standard arguments against temporal preference are much less persuasive than they are usually taken to be. The second goal is to explore two different avenues of argument that could be adopted, in order to show that temporal discounting of welfare may be permissible. The first involves simply an application of the method of reflective equilibrium, while the second involves consideration of the way that our abstract moral commitments are institutionalized. (shrink)

Controversies about time discounting loom large in decisions about climate change. Prominently, a particularly controversial debate about time discounting in climate change decision-making has been conducted within climate economics, between the authors of Stern et al. and their critics :977–981, 2006; Weitzman in J Econ Lit XLV:703–724, 2007; Nordhaus in J Econ Lit XLV:686–702, 2007). The article examines the role of values in this debate. Firstly, it is shown that time discounting is a case in which values are key because (...) it is at heart an ethical problem. Secondly, it is argued that time discounting in climate economics is a case of economists making frequent and routine references to ethical values and indeed conduct ethical debates with each other. Thirdly, it is argued that there is evidence for deep and pervasive entanglement between facts and values in the prevalent methodologies for time discounting. Finally, it is argued that this means that economists have given up the ‘value-free ideal’ concerning time discounting, and discussed how the current methodology of time discounting in economics can be improved. (shrink)

Several areas of welfare economics seek to evaluate states of affairs as a function of interpersonally comparable individual utilities. The aim is to map each state of affairs onto a vector of individual utilities, and then to produce an ordering of these vectors that can be represented by a mathematical function assigning a real number to each. When this approach is used in intertemporal contexts, a central theoretical question concerns the evaluative weight to be applied to utility coming at different (...) times. This question concerns the rate of pure time preference, which is one key determinant of the social discount rate. This article argues that the standard philosophical account of pure time preference is mistaken, because it ascribes to economists a methodological commitment they need not, and often do not, accept. This in turn undercuts the most common philosophical objection to pure time preference, which traces at least to Rawls’s A Theory of Justice. The article then evaluates three further objections to pure time preference, concluding that it might still be defensible under certain circumstances. The article closes by articulating a final argument that is suggested by the “Social, Economic and Ethical Concepts and Methods” chapter of the most recent Intergovernmental Panel on Climate Change report. If this further argument is sound, it would constitute a decisive objection to pure time preference as it currently figures in much intertemporal welfare economics. (shrink)

The urgent importance of dealing with the climate crisis has led some influential theorists to argue that at least some demands for justice must give way to pragmatic and strategic considerations. These theorists (Cass Sunstein, Eric Posner, and David Weisbach, all academic lawyers, and John Broome, an academic philosopher) contend that the failures of international negotiations and other efforts to change economic policies and practices have shown that moral exhortations are worse than ineffective. Although Broome's position is similar in these (...) respects to that of Sunstein, Posner and Weisbach, it differs in other important respects, including his understanding of the idea of justice, his disagreement with the policy approach (which he calls "efficiency with sacrifice") favored by the economists Nicholas Stern and William Nordhaus, and his proposal for establishing a new international financial institution, a World Climate Bank, in addition to putting a price on carbon. Elsewhere I offer a critical analysis of the position taken by Posner and Weisbach in their book, Climate Change Justice. Their arguments against allowing principles of distributive justice (narrowly understood) to constrain treaty negotiations fail to rule out the principles of John Rawls' Law of Peoples (which is a conception of the moral basis of a just international order, including states' obligations to secure basic human rights for all). Therefore their arguments against shaping climate treaties to reflect any principles of justice do not succeed in supporting their position. Here I offer a critical analysis of Broome's position. I raise and discuss objections to Broome's proposal for a WCB, and I argue that the continued relevance of these objections is contingent on how the proposal for a WCB may get developed. (shrink)

In this volume, Stephen M. Gardiner and David A. Weisbach present arguments for and against the relevance of ethics to global climate policy. Gardiner argues that climate change is fundamentally an ethical issue, since it is an early instance of a distinctive challenge to ethical action, and ethical concerns are at the heart of many of the decisions that need to be made. Consequently, climate policy that ignores ethics is at risk of.

Obstacles to achieving a global climate treaty include disagreements about questions of justice raised by the UNFCCC's principle that countries should respond to climate change by taking cooperative action "in accordance with their common but differentiated responsibilities and respective capabilities and their social and economic conditions". Aiming to circumvent such disagreements, Climate Change Justice authors Eric Posner and David Weisbach argue against shaping treaty proposals according to requirements of either distributive or corrective justice. The USA's climate envoy, Todd Stern, takes (...) a similar position. In this article I explain the practical and theoretical drawbacks of Posner & Weisbach's welfarist perspective and propose an alternative. I show that their arguments fail to rule out John Rawls' non-utilitarian, political conception of international justice and human rights, the Law of Peoples. On this basis I develop a conception of climate justice that highlights implications of some of Rawls' principles and adds a principle for determining fair shares of climate -treaty-related benefits and burdens. I propose this conception as a moral framework for negotiating a treaty that would promote human welfare consistently with requirements of justice, and I argue that a treaty proposal satisfying these requirements could best satisfy Posner & Weisbach's own feasibility criteria. (shrink)

Carbon offsetting can be loosely characterized as a mechanism by which an organization or individual contributes to a scheme that is projected either to remove carbon dioxide from the atmosphere or to deliver carbon dioxide emission reductions on the part of other organizations or individuals. An activity that has been offset therefore purports to make no long-term net contribution to atmospheric greenhouse gas concentrations. The ethical basis for using carbon offsetting as an approach to tackling climate change is very much (...) contested. We seek to expose some of the underlying reasons for these ethical disagreements. We show that they relate both to empirical disagreements about what the likely benefits of offsetting are and, more fundamentally, to principled disagreements about the right way to discharge duties to deliver carbon reductions. (shrink)

Critics of carbon mitigation often appeal to what Jonathan Glover has called ‘the argument from no difference’: that is, ‘If I don’t do it, someone else will’. Yet even if this justifies continued high emissions by the industrialised countries, it cannot excuse business as usual. The North’s emissions might not harm the victims of climate change in the sense of making them worse off than they would otherwise be. Nevertheless, it receives benefits produced at the latter’s expense, with the result (...) that it has more than it deserves, and that victims will have less. This enrichment is unjust; unjustly enriched agents ought to make compensation. The best form of compensation is vigorous action against climate change. (shrink)

Esteemed philosopher John Broome avoids the familiar ideological stances on climate change policy and examines the issue through an invigorating new lens. As he considers the moral dimensions of climate change, he reasons clearly through what universal standards of goodness and justice require of us, both as citizens and as governments. His conclusions—some as demanding as they are logical—will challenge and enlighten. Eco-conscious readers may be surprised to hear they have a duty to offset all their carbon emissions, while policy (...) makers will grapple with Broome’s analysis of what if anything is owed to future generations. From the science of greenhouse gases to the intricate logic of cap and trade, Broome reveals how the principles that underlie everyday decision making also provide simple and effective ideas for confronting climate change. Climate Matters is an essential contribution to one of the paramount issues of our time. (shrink)

Climate change poses grave threats to many people, including the most vulnerable. This prompts the question of who should bear the burden of combating ?dangerous? climate change. Many appeal to the Polluter Pays Principle. I argue that it should play an important role in any adequate analysis of the responsibility to combat climate change, but suggest that it suffers from three limitations and that it needs to be revised. I then consider the Ability to Pay Principle and consider four objections (...) to this principle. I suggest that, when suitably modified, it can supplement the Polluter Pays Principle. (shrink)

Challenging, with several powerful arguments, some of our deepest beliefs about rationality, morality, and personal identity, Parfit claims that we have a false view about our own nature. It is often rational to act against our own best interersts, he argues, and most of us have moral views that are self-defeating. We often act wrongly, although we know there will be no one with serious grounds for complaint, and when we consider future generations it is very hard to avoid conclusions (...) that most of us will find very disturbing. (shrink)

"Although the task of formulating an appropriate policy response to the problem of anthropogenic climate change is one that raises a number of very difficult normative issues, environmental ethicists have not played an influential role in government deliberations. This is primarily due to their rejection of many of the assumptions that structure the debates over policy. This book offers a philosophical defense of these assumptions, in order to overcome the major conceptual barriers to the participation of philosophers in these debates. (...) There are five important barriers: First, the policy debate presupposes a stance of liberal neutrality, as a result of which it does not privilege any particular set of environmental values over other concerns. Second, it assumes ongoing economic growth, along with a commitment to what is sometimes called a weak sustainability framework when analyzing the value of the bequest being made to future generations. Third, it treats climate change as fundamentally a collective action problem, not an issue of distributive justice. Fourth, there is the acceptance of cost-benefit analysis, or more precisely, the view that a carbon pricing regime should be guided by our best estimate of the social cost of carbon. And finally, there is the view that when this calculation is undertaken, it is permissible to discount costs and benefits, depending on how far removed they are from the present. This book attempts to make explicit and defend these presuppositions, and in so doing offer philosophical foundations for the debate over climate change policy"--. (shrink)

The three main types of policies for addressing climate change are command and control regulation, carbon taxes (or price instruments), and cap and trade (or quantity instruments). The first question in the ethics of carbon pricing is whether the latter two (price and quantity instruments) are preferable to command and control regulation. The second question is, if so, how should we evaluate the relative merits of price and quantity instruments. I canvass relevant arguments to explain different ways of addressing these (...) important policy questions, suggesting that carbon pricing is preferable to command and control regulation, and that price instruments have the theoretical edge over quantity instruments. [Open access]. (shrink)

This chapter introduces several distinctions relevant to what is called the “discounting problem”, since the issue is how (future) costs and benefits are discounted to make them comparable in present terms. The author defends the claim that there are good reasons to adopt Ramsey-style discounting in the context of climate change: the Ramsey rule is robust, flexible, and well-understood. An important distinction involved in discounting—“descriptivism” and “prescriptivism”—is discussed. It is argued that, even if we adopt prescriptivism, and accept that this (...) means there is need for moral experts in parameter assignments, there is a significant issue. The type of moral expertise required for the discounting problem will not involve knowledge of moral theory—thus making moral philosophy unhelpful in terms of making particular parameter assignments, despite these being substantive moral judgments. (shrink)

Carbon pricing is one of the most politically important approaches for the mitigation of climate change in the world today. Most political actors who are not committed to climate change denial favor carbon pricing, either as emissions trading or carbon taxation. In this article, I argue that carbon pricing should be considered unfair in most of its forms. I present a line of criticism called the Unfair Burdens Argument. It states that the most politically relevant ways to price carbon needlessly (...) burden the less affluent more than the more affluent. This is unfair because, among other things, the more affluent have on average done more to create the problem of climate change in the first place. Principles for the fair distribution of burdens under climate change mitigation like the Polluter Pays Principle, which were thought to support carbon pricing, turn out to speak against it, when interpreted properly. Although the Unfair Burdens Argument on its own cannot show that carbon pricing is impermissible, it offers important clues for what a morally permissible form of climate change mitigation would look like. (shrink)

Climate change is the most difficult threat facing humanity this century and negotiations to reach international agreement have so far foundered on deep issues of justice. Providing provocative and imaginative answers to key questions of justice, informed by political insight and scientific understanding, this book offers a new way forward.

I consider the plausibility of discounting for kinship, the view that a positive rate of pure intergenerational time preference is justifiable in terms of agent-relative moral reasons relating to partiality between generations. I respond to Parfit's objections to discounting for kinship, but then highlight a number of apparent limitations of this approach. I show that these limitations largely fall away when we reflect on social discounting in the context of decisions that concern the global community as a whole, such as (...) those related to global climate change. (shrink)

ABSTRACT In Debating Climate Ethics, David Weisbach and I offer contrasting views of the importance of ethics and justice for climate policy. I argue that ethics is central. Weisbach advocates for climate policy based purely on narrow forms of self-interest. For this symposium, I summarize the major themes, and extend my basic argument. I claim that ethics gets the problem right, whereas dismissing ethics risks getting the problem dangerously wrong, and perpetuating profound injustices. One consequence is that we should reject (...) the alleged “feasibility constraint” of short-term, economic self-interest. (shrink)

This chapter qualitatively lays out some of the ways that climate change impacts are evaluated in integrated assessment models (IAMs). Putting aside the physical representations of these models, it first discusses some key social or structural assumptions, such as the damage functions and the way growth is modeled. Second, it turns to the moral assumptions, including parameters associated with intertemporal evaluation and interpersonal inequality aversion, but also assumptions in population ethics about how different-sized populations are compared and how we think (...) about distributing goods across or within times. The intention is to survey the morally important assumptions that go into estimates of the social cost of carbon, the marginal cost of an additional tonne of carbon dioxide to society. (shrink)

The health co-benefits of CO2 mitigation can provide a strong incentive for climate policy through reductions in air pollutant emissions that occur when targeting shared sources. However, reducing air pollutant emissions may also have an important co-harm, as the aerosols they form produce net cooling overall. Nevertheless, aerosol impacts have not been fully incorporated into cost-benefit modeling that estimates how much the world should optimally mitigate. Here we find that when both co-benefits and co-harms are taken fully into account, optimal (...) climate policy results in immediate net benefits globally, overturning previous findings from cost-benefit models that omit these effects. The global health benefits from climate policy could reach trillions of dollars annually, but will importantly depend on the air quality policies that nations adopt independently of climate change. Depending on how society values better health, economically optimal levels of mitigation may be consistent with a target of 2 °C or lower. (shrink)

This paper argues that extortion is a clear threat in intergenerational relations, and that the threat is manifest in some existing proposals in climate policy and latent in some background tendencies in mainstream moral and political philosophy. The paper also claims that although some central aspects of the concern about extortion might be pursued in terms of the entitlements of future generations, this approach is likely to be incomplete. In particular, intergenerational extortion raises issues about the appropriate limits to the (...) sway of central values such as welfare and distributive justice. We should be wary of ways in which such values invite us to buy off, or perhaps to join, an intergenerational climate Mafia. (shrink)

Cap-and-trade systems for greenhouse gas emissions are an important part of the climate change policies of the EU, Japan, New Zealand, among others, as well as China and Australia. However, concerns have been raised on a variety of ethical grounds about the use of markets to reduce emissions. For example, some people worry that emissions trading allows the wealthy to evade their responsibilities. Others are concerned that it puts a price on the natural environment. Concerns have also been raised about (...) the distributional justice of emissions trading. Finally, some commentators have questioned the actual effectiveness of emissions trading in reducing emissions. This paper considers these three categories of objections – ethics, justice and effectiveness – through the lens of moral philosophy and economics. It is concluded that only the objections based on distributional justice can be sustained. This points to reform of the carbon market system, rather than its elimination. (shrink)

Climate change and justice are so closely associated that many people take it for granted that a global climate treaty should--indeed, must--directly address both issues together. But, in fact, this would be a serious mistake, one that, by dooming effective international limits on greenhouse gases, would actually make the world's poor and developing nations far worse off. This is the provocative and original argument of Climate Change Justice. Eric Posner and David Weisbach strongly favor both a climate change agreement and (...) efforts to improve economic justice. But they make a powerful case that the best--and possibly only--way to get an effective climate treaty is to exclude measures designed to redistribute wealth or address historical wrongs against underdeveloped countries. In clear language, Climate Change Justice proposes four basic principles for designing the only kind of climate treaty that will work--a forward-looking agreement that requires every country to make greenhouse--gas reductions but still makes every country better off in its own view. This kind of treaty has the best chance of actually controlling climate change and improving the welfare of people around the world. (shrink)

Pure time preference is a preference for something to come at one point in time rather than another merely because of when it occurs in time. In opposition to Sidgwick, Ramsey, Rawls, and Parfit we argue that it is not always irrational to be guided by pure time preferences. We argue that even if the mere difference of location in time is not a rational ground for a preference, time may nevertheless be a normatively neutral ground for a preference, and (...) this makes it plausible to claim that the preference is rationally permitted. (shrink)

A book chapter (about 9,000 words, plus references) presenting an act-consequentialist approach to the ethics of climate change. It begins with an overview of act consequentialism, including a description of the view’s principle of rightness (an act is right if and only if it maximizes the good) and a conception of the good focusing on the well-being of sentient creatures and rejecting temporal discounting. Objections to act consequentialism, and replies, are also considered. Next, the chapter briefly suggests that act consequentialism (...) could reasonably be regarded as the default moral theory of climate change, in the sense that a broadly act-consequentialist framework often seems implicit in both scholarly and casual discussions of the ethics of climate change. The remainder of the chapter explores three possible responses to the threat of climate change: having fewer children to reduce the number of people emitting greenhouse gases; taxing greenhouse-gas (GHG) emissions (commonly called a “carbon tax”) to discourage GHG-emitting behavior; and reducing poverty to lessen personal, familial, and community vulnerability to the harms of climate change. (shrink)

I argue that the use of a social discount rate to assess the consequences of climate policy is unhelpful and misleading. I consider two lines of justification for discounting: (i) ethical arguments for a "pure rate of time preference" and (ii) economic arguments that take time as a proxy for economic growth and the diminishing marginal utility of consumption. In both cases I conclude that, given the long time horizons, distinctive uncertainties, and particular costs and benefits at stake in the (...) climate context, discount rates are at best a poor proxy for the normative considerations they are meant to represent. (shrink)

This paper examines the nexus between climate change and trade governance from a normative perspective. Only little research attention has been paid to assessing the interactions between empirical and normative approaches to climate change in the context of potential trade measures. To this end, the paper focuses on currently discussed border carbon adjustment measures. The paper assesses these trade measures from a normative perspective: it explores whether they are compatible or in conflict with development ethics on the one hand and (...) with climate ethics on the other. The paper finds that border adjustment measures are both a potential threat to development, as well as to a workable climate agreement. It argues that they are therefore both in conflict with development as well as climate ethics concerns. From a development ethics perspective, border adjustment measures are objectionable for two reasons. First, they hurt developing countries and above all the ones that are vulnerable in terms of relying only on few export goods. Second, border adjustment measures restrict market access for developing countries and thereby undermine the potential of trade to foster development. From a climate ethics perspective, border adjustment measures are objectionable for three reasons. First, border adjustment measures amount to unilaterally changing whatever global burden-sharing deal has been agreed to—thereby undermining procedural justice. Second, border adjustment measures disregard the consumption-dimension: it might be questioned whether it is fair to focus exclusively on making producers pay for emissions rather than also holding those responsible that import and consume the goods that incorporate these emissions. Third, even if border adjustment measures and countries with low emissions are exempted from border adjustment measures, they still burden countries that bear no historic responsibility for current high levels of greenhouse gases in the atmosphere, thereby undermining distributive justice by being in conflict with the polluter pays principle. (shrink)

This paper examines explore the issues of intergenerational equity raised by climate change. A number of different reasons have been suggested as to why current generations may legitimately favor devoting resources to contemporaries rather than to future generations. These - either individually or jointly - challenge the case for combating climate change. In this paper, I distinguish between three different kinds of reason for favoring contemporaries. I argue that none of these arguments is persuasive. My answer in each case appeals (...) to the concept of human rights. It maintains that a human rights-centered perspective to climate change enables us to address each of these reasons. (shrink)

Concern for the rapidly growing scale and intensity of the human exploitation of the environment, in particular the alienation of natural ecosystems, but also resource exhaustion, pollution, and congestion, leads one to wonder about the short time. horizons allowed for in decision making. Time preference is dictated by the rate of interest, allowing in practice a horizon often not exceeding several decades. I argue that this is unsatisfactory. Some minimal social rate of discount should not be enforced. Instead, it is (...) more feasible to set absolute environmental standards, thereby introducing quantity constraints on our decision making, within which time preference can be permitted to find its own level. This acknowledges that the myopia of human vision may not be a flaw but rather a biological design which has served us weIl in evolution. It may, therefore, be better to change the rules by introducing self-imposed collective constraints than to try to change the shortsightedness of people in their day-to-day grass-roots decision making. (shrink)

[Comment] Donald Trump’s executive order on energy limits the costs and benefits of carbon to domestic sources. The argument for this executive order is that carbon policies should not be singled out from other policies as globally inclusive. Two independent arguments are offered for adopting a global social cost of carbon. The first is based on reinforcing norms in the face of commons tragedies. The second is based on the limitations of consequentialist analyses. We can distinguish consequences for which probabilistic (...) indifference is appropriate. The mechanisms for global effects for carbon are well-understood, whereas most policy effects are primarily domestic. [Open access]. (shrink)

In Debating Climate Ethics, Stephen Gardiner and I offer our views on how ethics or theories of justice more generally apply to climate change and possibly help inform climate change policy. It is...

Since 2011, the focus of international negotiations under the UNFCCC has been on producing a new climate agreement to be adopted in 2015. This phase of negotiations is known as the Durban Platform for Enhanced Action. The goal has been to update the global effort on climate for long-term cooperation. In this period, various changes have been contemplated on the design of the architecture of the global climate effort. Whereas previously, the negotiation process consisted of setting mandated targets exclusively for (...) developed countries, the current setting requests of each country to pledge its contribution to the climate effort in the form of Intended Nationally Determined Contributions. The shift away from establishing negotiated targets for rich countries alone towards a universal system of participation through intended contributions raised persistent questions on how exactly the new agreement can ensure equitable terms. How to conceptualize equity within the 2015 climate agreement, and beyond, is the focus of this paper. The paper advances a framework on equity, which moves away from substantive moral conceptions of burden allocation toward refining principles of public reason specially designed for the negotiation process under the UNFCCC. The paper outlines the framework’s main features and discusses how it can serve a facilitating role for multilateral discussion on equity on a long-term basis capable of adapting to changing circumstances. (shrink)

For the last 20 years, there has been lively debate about which principle of distributive and corrective justice should be used in dividing, among the various countries, the costs associated wit...