The Pacala-Socolow Group has proposed a new approach to the allocation of a global CO2 emissions target among the nations of the world, based on a reinterpretation of concept of “common but differentiated responsibilities” (language in the current international agreements), so that the phrase refers to individuals rather than nations. In this formulation, obligations are the same for individuals with similar life-styles, independent of the per-capita features of the country in which they live. Follow-on work is aimed at modeling CO2 emissions generated by activities strongly correlated with wealth, including travel by air and meat-eating.

The group also hosted a workshop in June devoted to biofuel feedstock, directed by David Tilman and Socolow. They assembled a small group of leaders in the current debate about the full environmental costs of this resource. A joint statement is being prepared for publication.

Other policy-related work includes a study of increased environmental investment in China and work on geoengineering.

The Oppenheimer Group has initiated a project on the history of environmental assessments, designed to be transferable to scientific assessment of global climate change. An intriguing dimension of this work is “negative learning” — the idea that the history of science is marked by many wrong turns, rather than by successive approximations converging on the truth.


Beyond Wedges – Focusing on the Emissions of Individuals

Shoibal Chakravarty is leading an effort to formulate a new framework for assessing national obligations for carbon mitigation. The new approach frames the principle of “common but differentiated responsibilities” at the level of individuals, not nations. The scheme blends fairness and pragmatism to propose “one rule for everyone,” where all those with the same emissions are treated equally, wherever they live. A “universal individual emissions cap” is defined transparently from a global emissions target. National targets are derived by summing the excess emissions of all “high emitter” individuals in a country—“high emitters” are those whose emissions exceed the “individual emissions cap.”

An emissions distribution for each country is estimated using income distribution data from the World Bank, plus national emissions data and projections from the Energy Information Administration. Using this information, the team has linked income to carbon emissions and determined a universal emissions cap and emissions target for all countries. The approach also provides for lifeline emissions to the world’s poor and shows that energy, poverty and climate change can be addressed simultaneously. For example, reducing global emissions in 2030 from a “Business as Usual” projection of 43 Billion tons of CO2 to 30 Billion tons (a 30% global cut with respect to BAU for that year and essentially the same global emissions as in 2008) will require the participation of 1.1 Billion people who emit above 10.8 tons of CO2 per year. This cap corresponds to an average global income of about $39,000 (PPP, in 2000 dollars). Providing lifeline emissions of 1 ton of CO2 per year in 2030 to the poorest 2.7 Billion people will instead involve 1.3 Billion people and reduce the “individual emissions cap” to 9.6 tons of CO2 per year.

The proposal is aimed at the critical period of the next 20-30 years where the researchers foresee dramatic change as many countries become richer and a global middle class develops. The policy proposal provides a unified approach to treat both developed and developing countries simultaneously. It begins by putting most of burden of emissions mitigation on the developed countries and slowly shifts the responsibility on the fast growing developing countries as they grow richer. The proposal also benefits by being flexible and easily updated for different global targets.

2008 saw the completion of a paper: “Climate Policy Based on Individual Emissions,” and presentations of its ideas to a range of international audiences, notably including at the Conference of the Parties to the Framework Convention on Climate Change in Bali.


Geoengineering – Injection of Aerosols Into the Stratosphere

A new area of activity in the group is the evaluation of the feasibility and impacts of schemes to engineer the earth. In August, Socolow participated in a week-long workshop in Santa Barbara on the injection of aerosols into the stratosphere for albedo enhancement to counteract greenhouse gas warming. The workshop has produced a report that outlines the required R&D portfolio that could sort how actually to achieve effective aerosol deployment, the merits and risks of this strategy, and the situations in which the case for deployment might be compelling. Socolow is also the co-chair of a new study on the direct capture of CO2 from the atmosphere by chemical and physical means. Here, CMI is leveraging a new study being conducted by the Panel on Public Affairs of the American Physical Society. His co-chair is William Brinkman, former Vice-President for Research at Bell Laboratories.


Environmental Investment in China

Yuan Xu is working with Bob Williams and Rob Socolow to shed light on the extraordinary and unexpected turn toward environmental investment in China since 2006, as manifested in particular in sulfur dioxide scrubbing at coal plants. There has been a remarkable increase in the level of installation and operation of scrubbers to improve regional air quality and reduce adverse impacts on health and agriculture. Conventional economic models would have predicted that such a high level of effort would not occur until China had reached a higher per capita income.

With the help of Chinese written references and some field verification, the researchers documented the rapid deployment of sulfur dioxide scrubbers at coal power plants in 2006 and 2007. Scrubbers were installed in each of these years at plants with more than 100,000 megawatts of total generating capacity, overtaking the rate of construction of new coal power plants. Scrubber installation in each year equaled the entire scrubber capacity in the U.S. The team has described the surprising scale of investment in a paper titled “China’s Rapid Deployment of CO2 Scrubbers.”


Lessons from Recent Scientific Assessments

Michael Oppenheimer and colleagues are continuing their research into “negative learning” and its impact on climate policy. Keynyn Brysse, a historian of science, has just begun a twoyear postdoctoral research project to investigate the history of scientific assessments of ozone depletion. This project is part of the new joint initiative between Michael Oppenheimer at Princeton and Naomi Oreskes at UC San Diego.

The role of scientific assessments in the evaluation of knowledge has expanded over the past three or four decades to become an integral factor in shaping government policy on climate change. But how well have these scientific assessments worked, and how might they be made to work more efficiently and effectively in the future? The ozone case, particularly the creation of the Montreal Protocol, is widely regarded as an example of successful policymaking (which came about, some analysts have argued, as a result of widespread scientific consensus). At the same time, it is also an example of at least two scenarios that scientists and policy makers would wish to avoid if possible: an unexpected outcome of great import (the Antarctic ozone hole), and the tendency to follow a path of learning that turns out to be wrong (negative learning). In the case of ozone depletion, scientists initially dismissed from consideration knowledge that turned out to be critical (heterogeneous chemical reactions occurring on the surfaces of polar stratospheric cloud particles and volcanic aerosols).

Why did scientists reject this key group of reactions, what made them reconsider, and what lessons can this example teach us about avoiding such mistakes in future climate research? This case of negative learning, as exemplified by the failure to include heterogeneous reactions in models and theories of stratospheric ozone depletion, will be the first question investigated by Brysse in her study of the history of ozone depletion science. Through analysis of published and archival documents, and through interviews with key scientists, policy makers, and members of industry, the history of scientific assessment of ozone depletion will be reconstructed and used to improve understanding of the scientific learning process, and to improve the process of scientific assessment of global climate change.