The social cost of carbon (SCC) is a central concept in climate change economics. This chapter explains the SCC and investigates it philosophically. As is widely acknowledged, any SCC calculation requires the analyst to make choices about the infamous topic of discount rates. But to understand the nature and role of discounting, one must understand how that concept—and indeed the SCC concept itself—is yoked to the concept of a value function, whose job is to take ways the world could be (...) across indefinite timespans and to rank them from better to worse. A great deal, therefore, turns on the details of the value function and on just what is meant by “better” and “worse.” This chapter seeks to explicate these and related issues, and then to situate them within the evolving landscape of federal climate policy in the United States. (shrink)

Mainstream climate economics takes global warming seriously, but perplexingly concludes that the optimal economic policy is to almost do nothing about it. This conclusion can be traced to just a few “normative” assumptions, over which there exists fundamental disagreement amongst economists. This paper explores two axes of this disagreement. The first axis measures faith in the invisible hand to adjust the natural thermostat. The second axis expresses differences in views on the efficiency and equity implications of climate action. The two (...) axes combined lead to a classification of conflicting approaches in climate economics. The variety of approaches does not imply a post-modern “anything goes”, as the contradictions between climate and capitalism cannot be wished away. (shrink)

This paper aims to highlight the role played by uncertainties in global justice theories. It will start by identifying four kinds of uncertainties that could potentially have an impact on the nature, content and very existence of global duties: first, uncertainties regarding the causes of global injustices; second, uncertainties regarding the consequences of global justice initiatives; third, uncertainties pertaining to the 'imperfect' character of certain global duties; and fourth, uncertainties regarding the conduct of others. It will discuss each of these (...) uncertainties in turn, with particular attention to their normative implications, their distinctively 'global' source, and the possibility of their being addressed. It will conclude with some reflections on how the normative issues raised by uncertainties related to spatial distance compare to those raised by uncertainties related to temporal distance. (shrink)

People seem to have pure time preferences about trade-offs concerning their own pleasures and pains, and such preferences contribute to estimates of people's individual time discount rate. Do pure time preferences also matter to interpersonal welfare trade-offs, including those concerning the welfare of future generations? Most importantly, should the intergenerational time discount rate include a pure time preference? Descriptivists claim that the intergenerational discount rate should reflect actual people's revealed preferences, and thus it should include a pure time preference. Prescriptivists (...) claim that the intergenerational discount rate should be based on moral analysis, and thus they (often) claim that the rate of pure time preference should be zero. I argue that regardless of which view is correct, a focus on pure time preference is misplaced. First, the most plausible interpretation of descriptive preferences for intergenerational trade-offs is that people are socially biased and not time biased. Second, social bias is superior to time bias as a prescriptive reason to discount the welfare of future people. Third, recent advances in measuring social bias as a social discount rate make social bias a viable replacement for time bias in economic analyses of intergenerational welfare trade-offs. (shrink)

Climate change is projected to have very severe impacts on future generations. Given this, any adequate response to it has to consider the nature of our obligations to future generations. This paper seeks to do that and to relate this to the way that inter-generational justice is often framed by economic analyses of climate change. To do this the paper considers three kinds of considerations that, it has been argued, should guide the kinds of actions that one generation should take (...) if it is to treat both current and future people equitably. In particular it examines the case for what has been termed pure time discounting, growth discounting and opportunity cost discounting; and it assesses their implications for climate policy. It argues that none of these support the claims of those who think they give us reason to delay aggressive mitigation policies. It also finds, however, that the second kind of argument can, in certain circumstances, provide support for passing on some of the costs of mitigation to future generations. (shrink)

This thesis is about the moral reasons we have to do less than best. It consists of six chapters. Part I of the thesis proposes, extends, and defends reasons to do less than best. In Chapter One (“The Conditional Obligation”) I outline and reject two recent arguments from Joe Horton and Theron Pummer for the claim that we have a conditional obligation to bring about the most good. In Chapter Two (“Agglomeration and Agent-Relative Costs”) I argue that agent-relative costs can (...) justify permissions to less than best in a far greater range of decisions contexts than we currently believe. In Chapter Three (“Risk and Aggregation”) I discuss how anti-aggregative moral theories deal with risk, whilst proposing an argument in favour of ex-post moral theories. -/- In Part II of the thesis, I discuss longtermism, presenting a series of reasons to believe we have both significant permissions and obligations to prioritise those in the short-term. In Chapter Four (“Listening to Future People”) I criticise a recent argument presented by Andreas Mogensen for the claim we cannot have obligations grounded in the wellbeing of future people. I then show that, even permitting the existence of obligations to future people, we still have significant reasons to resist longtermism on the grounds of partiality. In Chapter Five (“The Complaints of Future People”) I argue that scepticism about aggregation is inconsistent with an obligation, or indeed even a permission, to help far future people. In Chapter Six (“Leaving the Present Behind”) I explore the moral significance of “dooming”, whilst arguing that we have a pro tanto reason of fairness to prioritise aiding those currently in existence. (shrink)

Is drastic action against global warming essential to avoid impoverishing our descendants? Or does it mean robbing the poor to give to the rich? We do not yet know. Yet most of us can agree on the importance of minimising expected deprivation. Because of the vast number of future generations, if there is any significant risk of catastrophe, this implies drastic and expensive carbon abatement unless we discount the future. I argue that we should not discount. Instead, the rich countries (...) should stump up the funds to support abatement both for themselves and the poor states of the world. Yet to ask the present generation to assume all the costs of drastic mitigation.is unfair.Worse still, it is politically unrealistic.We can square the circle by shifting part of the burden to our descendants. Even if we divert investment from other parts of the economy or increase public debt, future people should be richer, so long as we avert catastrophe. If so, it is fair for them to assume much of the cost of abatement.What we must not do is to expose them to the threat of disaster by not doing enough. (shrink)

If the present generation refuses to bear the burden of mitigating global heating, could we motivate sufficient action by shifting that burden to our descendants? Several writers have proposed breaking the political impasse by funding mitigation through public debt. Critics attack such proposals as both unjust and infeasible. In fact, there is reason to think that some debt financing may be more equitable than placing the whole burden of mitigation on the present generation. While it might not be viable for (...) all countries to take this route simultaneously, a vanguard state, or group of states, could use public debt to fund an ambitious programme to develop inexpensive forms of clean low- or no-emission technology. This would ensure that vanguard actor or set of actors a leading role in those sectors while at the same time benefiting future generations around the world. -/- Key policy insights: (a) Debt-financed clean technology research can shift part of the burden of greenhouse gas mitigation to our descendants, breaking the political impasse of inaction or delayed action. (b) Far from being an injustice to future generations, this could actually be fairer than expecting the present generation to bear the full burden of mitigation. (c) Such an initiative may be most feasible if pursued by a vanguard actor. (shrink)

Climate change policy decisions are inescapably intertwined with future generations. Even if all carbon dioxide emissions were to be stopped today, most aspects of climate change would persist for hundreds of years, thus inevitably raising questions of intergenerational justice and sustainability. -/- The chapter begins with a short overview of discount rate debate in climate economics, followed by the observation that discounting implicitly makes the assumption that natural capital is always substitutable with man-made capital. The chapter explains why non-substitutability matters (...) if we are to take intergenerational justice seriously and invest aptly in mitigation. Non-substitutability simply implies that there are some forms of capital that cannot be substituted by another, and so consumption of one cannot be compensated with additional stocks of the other. The non-substitutability of critical natural capital can be defended without empirical data about preferences or the need to view the environment as a superior good, and the argument is presented through the language of keeping options open. -/- Those alive today make decisions about what natural capital to use and what to save for future. These choices are often represented as different points in a continuum of sustainability: weak sustainability is associated with a high degree of substitutability and therefore a lot of flexibility over what capital to consume, whereas strong sustainability is more stringent on substitutability. While it may be that in economical understanding weak and strong sustainability collapse into one another, philosophically the emphasis is slightly different. The chapter discusses how normative sustainability can be supported without ignoring opportunity costs and trade-offs. (shrink)

The empirically documented fact is that people’s preferences are time -biased. The main aim of this paper is to analyse in which sense do time -biases violate the requirements of rationality, as many authors assume. I will demonstrate that contrary to many influential views in psychology, economy and philosophy it is very difficult to find why the bias toward the near violates the requirements rationality. I will also show why the bias toward the future violates the requirements of rationality in (...) a very basic sense. (shrink)