Perspectives on Climate Change: Science, Economics, Politics, Ethics: Volume 5

The first group focuses on climate change science. In the opening chapter of this section, Jerry Mahlman (Senior Research Fellow at the National Center for Atmospheric Research) describes what he terms the “global warming dilemma.” According to Mahlman, the scientific community has reached an effective consensus that immediate and quite aggressive steps would be required to avoid climatic changes that are large in comparison with those observed in the Earth's geological record. Stabilizing atmospheric concentrations of carbon dioxide, for example, would require permanent emissions reductions of roughly 60–80%. Moreover, the long lags in the Earth's response to changes in the composition of the atmosphere suggests that even this stringent scenario would be insufficient to prevent moderate temperature increases in the coming decades. Based on his reading of the scientific literature, Mahlman concludes that deferring action until climate change has broadly recognized deleterious effects would most likely “lock in” quite profound environmental impacts with effects lasting for centuries and even millennia. In terms of mechanisms, this argument appeals to the view that today's greenhouse gas emissions might use up the Earth's assimilative capacity, thus increasing the length of time that greenhouse gases remain in the atmosphere. On top of this, Mahlman notes that most scientific studies have emphasized time scales of one century or less in evaluating climate impacts. But impacts such as sea-level rise, which would be strongly affected by the melting and breakup of glacial formations such as the West Antarctic Ice Sheet, occur over much longer time horizons with a high degree of irreversibility. This makes climate change an issue of intergenerational fairness that pits present society's willingness to bear significant economic costs against the goal of protecting future generations from environmental harms that are hypothetical and yet potentially catastrophic.

In 2001, the Intergovernmental Panel on Climate Change's Third Assessment Report revealed an important increase in the level of consensus concerning the reality of human-caused climate warming. The scientific basis for global warming has thus been sufficiently established to enable meaningful planning of appropriate policy responses to address global warming. As a result, the world's policy makers, governments, industries, energy producers/planners, and individuals from many other walks of life have increased their attention toward finding acceptable solutions to the challenge of global warming. This laudable increase in worldwide attention to this global-scale challenge has not, however, led to a heightened optimism that the required substantial reductions in carbon dioxide (CO2) emissions deemed necessary to stabilize the global climate can be achieved anytime soon. This fact is due in large part to several fundamental aspects of the climate system that interact to ensure that climate change is a phenomenon that will emerge over extensive timescales.

Although most of the warming observed during the 20th century is attributed to increased greenhouse gas concentrations, because of the high heat capacity of the world's oceans, further warming will lag added greenhouse gas concentrations by decades to centuries. Thus, today's enhanced atmospheric CO2 concentrations have already “wired in” a certain amount of future warming in the climate system, independent of human actions. Furthermore, as atmospheric CO2 concentrations increase, the world's natural CO2 “sinks” will begin to saturate, diminishing their ability to remove CO2 from the atmosphere. Future warming will also eventually cause melting of the Greenland and Antarctic ice sheets, which will contribute substantially to sea level rise, but only over hundreds to thousands of years. As a result, current generations have, in effect, decided to make future generations pay most of the direct and indirect costs of this major global problem. The longer the delay in reducing CO2 and other greenhouse gas emissions, the greater the burden of climate change will be for future life on earth.

Collectively, these phenomena comprise a “global warming dilemma.” On the one hand, the current level of global warming to date appears to be comparatively benign, about 0.6°C. This seemingly small warming to date has thus hardly been sufficient to spur the world to pursue aggressive CO2 emissions reduction policies. On the other hand, the decision to delay global emissions reductions in the absence of a current crisis is essentially a commitment to accept large levels of climate warming and sea level rise for many centuries. This dilemma is a difficult obstacle for policy makers to overcome, although better education of policy makers regarding the long-term consequences of climate change may assist in policy development.

The policy challenge is further exacerbated by factors that lie outside the realm of science. There are a host of values conflicts that conspire to prevent meaningful preventative actions on the global scale. These values conflicts are deeply rooted in our very globally diverse lifestyles and our national, cultural, religious, political, economic, environmental, and personal belief systems. This vast diversity of values and priorities inevitably leads to equally diverse opinions on who or what should pay for preventing or experiencing climate change, how much they should pay, when, and in what form. Ultimately, the challenge to all is to determine the extent to which we will be able to contribute to limiting the magnitude of this problem so as to preserve the quality of life for many future generations of life on earth.

A variety of gases, including water vapor (H2O), carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), add to the radiative forcing of Earth's atmosphere, meaning that they absorb certain wavelengths of infrared radiation (heat) that is leaving the Earth and thus raise the temperature of its atmosphere. Since glass has the same effect on the loss of heat from a greenhouse, these gases are known as “greenhouse” gases. It is fortunate that these gases are found in the atmosphere; without its natural greenhouse effect, Earth's temperature would be below the freezing point, and all waters on its surface would be ice. However, for the past 100 years or so, the concentrations of CO2, CH4, and N2O in the atmosphere have been rising as a result of human activities. An increase in the radiative forcing of Earth's atmosphere is destined to cause global warming, superimposed on the natural climate cycles that have characterized Earth's history.

In the southern hemisphere, the Antarctic continent is also experiencing a net loss in ice from the extensive glaciers and ice sheets that cover it. However, the connection between changes in Antarctic ice sheets and the global warming trend are much more uncertain than in the Arctic. The complex of changes in the Antarctic climate and the ice sheets are described in a later section of this chapter.

Anyone who follows climate change policy debates even casually knows that these debates are shot through with controversy about what ought to be done and who ought to be doing it. What sometimes get lost in these debates, however, are much deeper differences over the nature of the climate change problem itself. That is my focus in this chapter. I will take climate change as a prime example of broader debates over what constitutes “sustainable development” and draw upon different strands of the sustainability literature to show how these disagreements play out in the climate change context.

The theory of discounting is based on the assumption that people's observed behavior in markets for savings and investment reveals their subjective preferences regarding trade-offs between present and future economic benefits. A person who borrows money at the annual interest rate r, for example, shows a willingness to pay (1+r)t dollars t years in the future to obtain one dollar in the present. On the other side of this transaction, the lender demands (1+r)t future dollars in exchange for each dollar loaned out today. In the logic of this situation, both borrowers and lenders behave as if one dollar of future currency has a “present value” of just

Fairness is central to any multilateral regime, that is, any agreement between multiple nation-states to address and resolve a common problem. Climate change mitigation is among the key global environmental concerns that will require a common agenda, approach, and set of actions by the community of nations. To that end, global climate negotiations under the United Nations Framework Convention on Climate Change (UNFCCC, 1992) are centered on establishing a multilateral framework to control greenhouse gas (GHG) emissions from all nations and to help those who would be affected by climate change.

Although the general theory of greenhouse warming has been understood by scientists since the end of the nineteenth century, an international regime to address the problem of climate change began to develop only in the late 1980s.¹ In the decade and a half since then, the regime has undergone a remarkable evolution. In 1992, states adopted the UN Framework Convention on Climate Change (UNFCCC), which took effect in 1994 and serves as the “constitution” for the international climate change regime.² In 1997, the UNFCCC was supplemented by the Kyoto Protocol, which requires industrialized countries to reduce their emissions of carbon dioxide and five other gases that contribute to the greenhouse effect (so-called “greenhouse gases” or GHGs for short). And the 2001 Marrakesh Accords further elaborate the Kyoto Protocol's regulatory regime, setting forth detailed rules for how the Kyoto Protocol will operate.

Whether we like it or not, global warming is shaping up as one of the most important challenges of the 21st century. It is going to drive far-reaching changes in how we live and work, power our homes, schools, factories, and office buildings, get from one place to another, manufacture and transport goods, and even farm and manage forests. It touches every aspect of our economy and our lives, and to ignore it is to live in a fantasy land where nothing ever has to change – and where we never have to accept what science tells us about what is happening to our world.

Within the field of international relations, global environmental governance is frequently discussed in terms of “international regimes,” defined as “social institutions that consist of agreed upon principles, norms, rules and decision-making procedures, and programs that govern the interaction of actors in specific issue areas” (Young, 1997, pp. 5–6). Viewed from the regime theory perspective, nation-states are seen as territorially bounded entities with a monopoly on the use of (economic or military) force (Agnew, 1999). As a result, they are assumed to have primary authority in matters of global environmental governance. It is nation-states that engage in the negotiation of international treaties (in which the elements of a regime may be formalized), which are then taken home to be either implemented or ignored as the nation-state sees fit. Given that political power is defined by state boundaries within the regime approach, the internal politics of nation-states is considered to be of relatively little import in much of the literature. Aside from some interest in the concept of sovereignty (Litfin, 1998), the notion of transgovernmental coalitions (Risse-Kappen, 1995; Slaughter, 1997), and two-level games (Putnam, 1988), in the main the state remains conceived as a homogenous and unitary actor, a “fixed territorial entity…operating much the same over time and irrespective of its place within the geopolitical order” (Agnew & Corbridge, 1995, p. 78). While a recent focus on knowledge and the role of nonstate actors in international regimes has led to a revision of the nature of interests, politics, and influence, the state remains defined in terms of national government, albeit with potential internal conflicts and the roles of domestic actors noted. Implicitly, regime theory assumes that subnational governments act under the (sole) influence and direction of national government. Critically, the potential role of subnational government is either ignored or subsumed within the nation-state.

In this chapter I claim that climate change poses important questions of global justice, both about mitigating the change that is now under way and about adapting to its consequences.¹ I argue for a mixed policy of mitigation and adaptation, and defend one particular approach to mitigation. I also claim that those of us who are rich by global standards and benefit from excess emissions have strenuous duties in our roles as citizens, consumers, producers, and so on to reduce our emissions and to finance adaptation.

One feature of Utilitarianism that provides its link to rational decision making is that the basic principle of utility demands that one maximize the good. One can disagree about what exactly the good is – perhaps it is pleasure, autonomy, beauty, or some set of items on a list mixing a variety of intrinsic goods. However, whatever the good turns out to be, we ought – morally – to maximize it. A failure to maximize the good is seen as not only a moral failure but also a rational one. So, for example, suppose that a friend of yours offers you a choice between $100 and $10. Most would hold that the rational thing to do is maximize the good and take the $100, all other things being equal. The person who took the $10 option would be considered irrational and imprudent. Maximizing or optimizing one's finances, all other things being equal, would be prudent, but the general point about maximizing carries over to the moral area. What one ought to do, morally, is maximize the good. In the moral area, this means maximizing human well-being, impartially considered. The above illustration is an artificial one, and real life introduces all sorts of complexities such as how to weigh disparate goods and how to deal with risk and uncertainty. However, the basic point that one ought to maximize the good, or do the best one can, stands.

I have applied the phrase “the date of the technological transition” to the year in human history in which the accumulated atmospheric total of all GHGs ceases to grow.⁵ Carbon dioxide from the combustion of fossil fuel is only one GHG, of course, but increases in carbon dioxide have made by far the greatest contribution to the swelling of the total. Perhaps quantities of some other GHGs would even need to continue to grow, perhaps not – this is a murkier realm. But if emissions of carbon dioxide were reduced sufficiently, quantities of other GHGs could, if necessary, increase while total annual emissions of all GHGs declined because carbon dioxide is such a large part of current annual emissions of all GHGs and of annual increases in emissions of all GHGs. Reductions in emissions of carbon dioxide could “make room” for any necessary increases in other GHG emissions.

To make the issue stark, let us begin with a few assumptions. I believe that these assumptions are probably roughly accurate, but none is certain, and I will not try to justify them here. Instead, I will simply take them for granted for the sake of argument.¹