Energy Policy in the Greenhouse

From warming fate to warming limit

Florentin Krause, Wilfrid Bach, Jon Koomey

• Éditeur: Routledge
• Année: 2013
• ISBN:
  9781134051052
• Édition: 1
• Sujet: Negocios y empresa
• Sous-sujet: Negocios en general

The globe is warming and while no one knows what will happen as a result, it is clear that slowing the process is a necessary goal. Other studies have considered 'warming fates', this one brings sophisticated computer modeling to bear on ways of minimizing the risks.

Fossil carbon emissions, other trace gases and releases from other sources are all taken into account, and the authors demonstrate the global need to produce a budget for cumulative releases between now and the year 2100. They also demonstrate the need to return to a rate of forest carbon storage equal to that of the mid-1980s. These budgets look at issues of international equity and the ways of moving to a binding agreement. The price of failure to control GHG emissions may be uncertain, but it will be more than anyone can afford. Political will lies at the root of successful climate stabilization and major capital and technology transfers to Third World countries will be needed if there is to be any chance of success. This book provides an agenda for advance.A book [which] throws into stark relief the mountain still to be climbed before the world community can agree on a credible programme to tackle global warming. David Thomas, Financial Times Originally published in 1991

PART ONE:

CLIMATE STABILIZATION AND THE LIMITS TO FOSSIL FUEL CONSUMPTION

Part One of this volume provides the scientific basis and risk-minimization arguments for specific limits on cumulative global fossil carbon emissions. As a core concept, we develop a budget for future carbon dioxide releases that would meet specified limits on the risks of human-induced climate change.

Chapter 1.1 reviews the current scientific understanding of the greenhouse effect, the history of the earth’s climate, and the expected impacts from global warming. These data are used to define a plausible risk-minimizing warming limit. A methodology is defined for translating this limit into targets for practical policy-making.

Chapter 1.2 presents climate modeling calculations for emission scenarios of the major greenhouse gases. These calculations indicate what range of emission reductions would be needed to limit the risks of climate change to specified levels.

Chapter 1.3 analyzes reduction potentials for trace gases other than fossil carbon dioxide. We review the range of emission reductions that could be achieved on the basis of various technological options and policy measures. (The equivalent analysis of fossil carbon dioxide reduction measures is the topic of Volume Two).

Chapter 1.4 derives an upper-limit cumulative global budget for future fossil carbon dioxide releases! This budget reflects the potentials identified in Chapter 1.3 for reducing other greenhouse gas emissions. It is then compared with fossil fuel reserves and resources, and with projected fossil fuel consumption in several published global energy scenarios.

CHAPTER 1.1

A TARGET-BASED, LEAST COST APPROACH TO CLIMATE STABILIZATION

A. INTRODUCTION

1. Wait-and-see versus risk minimization

Despite recent progress in putting the threat of global warming onto the international agenda (see Section B below), the debate over the greenhouse effect continues to be shaped by two diametrically opposed viewpoints. These views can be characterized as follows:

Don’t act until you are certain or wait-and-see. Analysts holding to this view believe that current scientific uncertainties are still too large to warrant costly preventative action. Instead, more research should be pursued to reduce scientific uncertainties.

Act now to minimize risks: Those holding to this view believe that current uncertainty cuts both ways: if major warming should come true, inaction could have catastrophic consequences. Society should therefore pursue investments and policies now to minimize such risks.

The competition between these two viewpoints revolves around the following fundamental issues:

• What aspects of the global warming threat are scientifically established fact, if any, and which are not?

• How costly would prevention be compared to adaptation?

• Would there be winners and losers, or would the consequences of global warming be catastrophic for the world as a whble?

• Is there reason to believe that remaining uncertainties could be satisfactorily resolved in a time frame that would still allow preventative global action later?

• Could improved scientific modeling tools be able to reliably distinguish between winners and losers?

What is established scientific fact and what is uncertain ?

The scientific community is in complete agreement that the atmospheric greenhouse effect governs global temperature.¹ In fact, heat entrapment due to radiative forcing of gases is one of the oldest and most well-established experimental findings of modem science, going back some 150 years. Moreover, the greenhouse effect is the only basis on which the enormous differences in atmospheric temperatures and climate between planets like Mars, Venus, and Earth can be explained.

What is also certain is that the atmospheric concentrations of a number of greenhouse gases have been rising and are continuing to rise, as shown by ongoing measurements in a global network of monitoring stations (Wuebbles and Edmonds 1988). There is compelling evidence that these increases must be attributed to human activities (Dickinson and Cicerone 1986).

Furthermore, data from trapped air samples in ice cores have shown that for the last 150,000 years, atmospheric carbon dioxide and methane concentrations have closely tracked the surface temperature changes brought on by glacial and interglacial periods.²

There is also virtually no debate in the scientific community that continuing rises in the atmospheric concentrations of carbon dioxide and other greenhouse gases will lead to global warming (CDAC 1983, Schneider 1989).

Finally, scientific research to date has firmly established the risk of catastrophic consequences from future climate warming. There is ample physical evidence that past changes in the earth’s surface temperature were related to major changes in sea levels, ice cover, forest cover, and regional climates. If these changes were to occur again in the world of today, their consequences would likely be catastrophic: imagine, for example, a global sea level rise of several meters (see Section D below). Though they might not occur, similar outcomes cannot be excluded as a consequence of future global warming.

What is uncertain is how much warming the earth will experience for a given increase in greenhouse gas concentrations (i.e., the climate sensitivity). It is also uncertain what the precise global and regional magnitudes and kinds of impacts will be: whether impacts will arrive gradually or suddenly; whether they will be catastrophic everywhere or only in some regions, and if so, where; and what monetary costs and benefits would be associated with these impacts.

Could research resolve these uncertainties in a timely manner?

Research could certainly improve the modeling tools of scientists by extensively measuring the geophysical and biogeochemical processes that are involved in climate responses to greenhouse warming. A key area would be the development and validation of a fully coupled atmosphere-ocean model. But both the data gathering and the computational tasks involved are so enormous that it would probably take one to two decades before results can be expected to significantly improve modeling capabilities (Schneider 1989).

Similarly, monitoring of climate change, though needed, will inherently be unable to answer the key question of climate sensitivity (i.e., the warming response to a doubled carbon dioxide concentration) in a timely manner. The emergence of any degree of warming from the statistical noise in the world’s temperature record is estimated to be five to fifteen years away. Once the phenomenon of warming has emerged from measurements, interpretations regarding climate sensitivity will still be impossible until the effect has become sufficiently large (see Chapter 1.2).

Meanwhile, because of the “memory” of the climate system, each year of monitoring and research without simultaneous preventative measures adds a further irrevocable increment to future warming. In fact, the sensitivity of the global climate to specific radiative forcings will never be resolved through measurement until the full climatic change is upon us.

In view of this difficulty of interpreting future temperature changes that could be obtained from global monitoring, Hansen (1989) argues that the soundest approach is to calculate the range of climate sensitivities that is consistent with past changes in global climate and atmospheric greenhouse gas concentrations —essentially data from warming experiments the earth conducted on itself. He reviews two sets of such paleoclimatic data: carbon dioxide and methane concentrations during the last 150,000 years as obtained recently from ice cores, and the surface temperature changes the earth underwent during the same period.

Though there is a strong correlation between the two sets of data, it is not clear whether the rises in CO₂ concentrations found in ice cores caused past warmings or whether past warmings brought on rising CO₂ concentrations. Hansen argues that this question is immaterial for the issue of climate sensitivity. In his view, the correlation between the two parameters describes how the greenhouse effect has governed the earth-atmosphere system in the past, irrespective of the sequence of events that set these changes in motion. His calculations result in approximately the same range of climate sensitivities as currently predicted by the major climate models (see Chapter 1.2).

These calculations thus add empirical weight to the climate sensitivities obtained from a bottom-up combination of scientific knowledge about individual geophysical processes, as done in climate modeling. Like recent sattelite data on the water vapor effect (Raval and Ramanathan 1989), these paleoclimatic data reinforce the scientific basis for predictions of significant global warming. At the same time, they do not narrow the substantial range of warming effects obtained from current models.

If the exact model-based quantification of climate change will remain elusive on the global level, this will be even more the case for predictions on a regional level. Nations that choose adaptation over collective prevention (in hopes of climatic improvements in their region) would be playing Russian roulette.

The wait-and-see approach is equivalent to converting the natural environments of all peoples and species into one huge laboratory—or, since this experiment has already inadvertently gotten underway, to continue and expand it. Any scientific research council would oppose such an experiment as unethical and irresponsible if it were proposed as a research project.

Risk minimization as a basis for greenhouse policy

The wait-and-see policy ignores that incurring risks has its own cost. Costs are only seen as existing on the prevention side of the ledger, while the risk-reducing benefits of preventative action are discounted. The principal rationale, i.e., that scientific uncertainty could be sufficiently resolved through research to eventually allow the application of conventional cost/benefit analysis, is faulty. The continued attractiveness of a wait- and-see policy among some constituencies is mainly explained by a lack of information about the nature of the problem, as well as by unbridled technological optimism, and in some cases, vested economic interests in the status quo.

The risk minimization approach to global warming, on the other hand, relies on a properly scientific outlook—not just in terms of the facts and risks that science has already established beyond question, but also in recognizing the inherent limits to striving for scientific certainty or, for that matter, for comprehensive and reliable monetary assessments of potential impacts.

In this paradigm, risks contribute to real costs. These risk-based costs can be expressed in the following simple equation:

(low or uncertain probability) x (catastrophic consequences)
= (major risk to society)

This perspective on risks is by no means unique to global warming. Huge military outlays are routinely made on the basis of this formula. Given the magnitude of climate risks (see Section D), global warming—and other environmental threats as well—could be treated as a new type of threat to global security.³ Just as military expenditures are justified as precautionary measures that buy insurance against perceived risks and threats, precautionary measures to reduce greenhouse gas emissions could be seen as a form of buying insurance against the risk and threat of climate change.

In one form or another, most existing environmental regulation is already based on this formula. In all cases, normative, risk-based perceptions have had to take over where scientific analysis and cost/benefit calculus reached their limits. The relevance of these public pol...