Comparative climate law reports

For those seeking to take a comparative approach to teaching climate law, there are reports from countries around the globe (along with a wealth of similar material) available as part of the Web site for the XVIIIth International Congress of Comparative Law . This could serve as a starting point for a series of presentations, a discussion of different national approaches, or a critical perspective on domestic initiatives.

Sunshades in Space? Oh My! Climate Geoengineering

One of the more exotic potential solar radiation management geoengineering technologies is the placement of sunshades in space to reflect or deflect solar radiation, either by lifting these reflectors into orbit around Earth or at the Lagrangian L1 point between the sun and Earth. A new article by Takanobu Kosugi is a very thorough assessment of the potential effectiveness of this scheme, as well as potential perils that the technology might pose to societies in the next century, Takanobu Kosugi, Role of Sunshades in Space as a Climate Control Option, 67 Acta Astronautica 241-253 (2010) (subscription required). This would be an excellent reading for graduate students or law students.

Among the key take-aways from the study:

  1. According to theoretical calculations, sunshade technology could reduce 1.8% of total solar radiation inflows, offsetting warming associated with a doubling of atmospheric carbon dioxide concentrations;
  2. Sunshade research is at a “germinal” stage, with large uncertainties in terms of the characteristics of such technologies, including critical issues e.g. the mass of sunshades required to reduce a certain among of solar radiation inflows;
  3. The cost of space launching of sunshades is projected at $6000/kg. currently; however, technological progress could ultimately reduce costs to $20/kg. assuming that the materials for sunshades could be extracted from the moon or an asteroid;
  4. For all scenarios involving the sunshade mass-effectiveness coefficient and equilibrium climate sensitivity (which likely ranges from 2-4.5C, but could even reach approximately 6C), deployment of sunshades are expected to become cost-effective for initial deployment in the middle of this century, a point at which temperatures are projected to have risen 2C above pre–industrial levels. Assuming climate sensitivity of 3C, sunshade deployment could reduce total societal costs by $240 billion; if climate sensitivity ultimately proves to be 6C, cost savings could rise to $1.9 trillion;
  5. There is a potential “termination problem” associated with deployment of sunshade technology, i.e. the potential for abrupt temperature rises if use of sunshades was suspended for any reason, especially in cases where the mass-effectiveness coefficient is low. The study indicates that with low mass-effectiveness coefficient, the termination of sunshade deployment in 2125 could result in temperatures increasing by between 0.14C-1.28C based on different assumptions of climate sensitivity. However, the study also emphasizes that even with temperature sensitivity of 6C, the temperature rise after termination is less than the 0.2C per decade temperature increase anticipated under a business as usual scenario without deployment;
  6. Continuous investment in research and development of $14 billion annually over the next quarter century would be a reasonable expenditure for sunshade technology.

This article could generate substantial class discussion. Some potential questions include:

  1. While the article doesn’t address moral hazard questions, are they related to the “termination problem” cited by the author?;
  2. Given the substantial costs projected for R&D for sunshade technologies, how does one assess opportunity costs vis-a-vis either other geoengineering schemes or mitigation/adaptation responses?;
  3. Does the sunshade approach pose any of the potential negative side effects that might be posed by other SRM approaches, e.g. changes in regional precipitation patterns, impacts on the ozone layer, etc. If not, would this obviate some of the potential governance problems associated with other SRM (or CDR) approaches?;
  4. What treaties might be relevant in terms of governing sunshade R&D or deployment?

Ethics and Climatic Uncertainty

From Donald Brown’s excellent blog on climate ethics:

A new article has been posted on ClimateEthics that argues that we have been tricked into asking the wrong questions of climate change science compared to the questions that ethics would ask climate change science. It is titled:

Have We Been Asking the Wrong Questions About Climate Change Science? Why Strong Climate Change Ethical Duties Exist Before Scientific Uncertainties are Resolved.

The article can be found at :

NYT commentaries on the abandonment of climate change legislation

The New York Times recently included two notable commentaries on the abandonment of efforts toward climate change legislation.  Andrew Revkin takes President Obama to task for abdicating leadership on the issue.  Tom Friedman takes a broader view, highlighting the public’s failure to demand action and the the role of climate change deniers. 

Both of these commentaries, especially Friedman’s, could be useful to include in readings for a class discussing the lack of climate change legislation in the U.S.  The obvious question, then, is where do we go from here?  From a legal perspective, we continue to look to state & local efforts, while pushing EPA to use the Clean Air Act as muscularly as possible.  Both of these, hopefully, could play a role in changing the political landscape as regulated entities will come to seek the predictability of comprehensive national legislation.

Casebook on REDD On-the-Ground Impacts

The Nature Conservancy, Conservation International and WWF have recently released Reducing Emissions from Deforestation and Degradation (REDD):  A Casebook of On-the-Ground Experience, which offers analysis of key REDD issues through investigation of specific cases.  The report endorses REDD, frequently using the cases to demonstrate how potential probelems with REDD can be overcome.  It thus comes across as a constructive assessment of REDD’s possiblities.  The examination of specific cases is particularly helpful because such studies are, unfortunately, often hard to find with the exception of a very few frequently discussed early REDD examples.

New National Academy of Sciences Study on Temperature Increases/Impacts

Below is the Executive Summary of an important new study by the U.S. National Academy of Sciences, entitled Stabilization Targets for Atmospheric Greenhouse Gas Concentrations.

The study assesses the link between specific increases in temperature and environmental impacts


Emissions of carbon dioxide from the burning of fossil fuels have ushered in a new epoch where human activities will largely determine the evolution of Earth’s climate. Because carbon dioxide in the atmosphere is long lived, it can effectively lock the Earth and future generations into a range of impacts, some of which could become very severe.
Therefore, emissions reductions choices made today matter in determining impacts experienced not just over the next few decades, but in the coming centuries and millennia. Policy choices can be informed by recent advances in climate science that quantify the relationships between increases in carbon dioxide and global warming, related climate changes, and resulting impacts, such as changes in streamflow, wildfires, crop productivity, extreme hot summers, and sea level rise.

Since the beginning of the industrial revolution, concentrations of greenhouse gases from human activities have risen substantially.
Evidence now shows that the increases in these gases very likely (>90 percent chance) account for most of the Earth’s warming over the past 50 years. Carbon dioxide is the greenhouse gas produced in the largest quantities, accounting for more than half of the current impact on Earth’s climate. Its atmospheric concentration has risen about 35 percent since 1750 and is now at about 390 ppmv, the highest level in at least 800,000 years. Depending on emissions rates, carbon dioxide concentrations could double or nearly triple from today’s level by the end of the century, greatly amplifying future human impacts on climate.

Society is beginning to make important choices regarding future greenhouse gas – emissions. One way to inform these choices is to consider the projected climate changes and impacts that would occur if greenhouse gases in the atmosphere were stabilized at a particular concentration level. The information needed to understand such targets is multifaceted: how do emissions affect global atmospheric concentrations and in turn global warming and its impacts?

This report quantifies, insofar as possible, the outcomes of different stabilization targets for greenhouse gas concentrations using analyses and information drawn from the scientific literature. It does not recommend or justify any particular stabilization target. It does provide important scientific insights about the relationships among emissions, greenhouse gas concentrations, temperatures, and impacts.


Carbon dioxide flows into and out of the ocean and biosphere in the natural breathing of the planet, but the uptake of added human emissions depends on the net change between flows, occurring over decades to millennia. This means that climate changes caused by carbon dioxide are expected to persist for many centuries even if emissions were to be halted at any point in time.

Such extreme persistence is unique to carbon dioxide among major agents that warm the planet. Choices regarding emissions of other warming agents, such as methane, black carbon on ice/snow, and aerosols, can affect global warming over coming decades but have little effect on longer-term warming of the Earth over centuries and millennia. Thus, long-term effects are primarily controlled by carbon dioxide.

The report concludes that the world is entering a new geologic epoch, sometimes called the Anthropocene, in which human activities will largely control the evolution of Earth’s environment. Carbon emissions during this century will essentially determine the magnitude of eventual impacts and whether the Anthropocene is a short-term, relatively minor change from the current climate or an extreme deviation that lasts thousands of years. The higher the total, or cumulative, carbon dioxide emitted and the resulting atmospheric concentration, the higher the peak warming that will be experienced and the longer the duration of that warming. Duration is critical; longer warming periods allow more time for key, but slow, components of the Earth system to act as amplifiers of impacts, for example, warming of the deep ocean that releases carbon stored in deep-sea sediments. Warming sustained over thousands of years could lead to even bigger impacts (see Box ES.1).


Widespread coastal flooding would be expected if warming of several degrees is sustained for millennia. Model studies suggest that a cumulative carbon emission of about 1000 to 3000 gigatonnes (billion metric tonnes carbon) implies warming levels above about 2°C sustained for millennia. This could lead to eventual sea level rise on the order of 1 to 4 meters due to thermal expansion of the oceans and to glacier and small ice cap loss alone. Melting of the Greenland ice sheet could contribute an additional 4 to 7.5 meters over many thousands of years.


To date, climate stabilization goals have been most often discussed in terms of stabilizing atmospheric concentrations of carbon dioxide (e.g., 350 ppmv, 450 ppmv, etc.). This report concludes that, for a variety of conceptual and practical reasons, it is more effective to assess climate stabilization goals by using global mean temperature change as the primary metric. Global temperature change can in turn be linked both to concentrations of atmospheric carbon dioxide (Table 1) and to accumulated carbon emissions.

An important reason for using warming as a reference is that scientific research suggests that many key impacts can be quantified for given temperature increases. This is done by scaling local to global warming and by “coupled linkages” that show how other climate changes, such as alterations in the water cycle, scale with temperature.

There is now increased confidence in how global warming levels of 1°C, 2°C, 3°C etc. (see °F conversion, right) would relate to certain future impacts. This report lists some of these effects per degree (°C) of global warming (see Figure ES.2), including:

* 5-10 percent changes in precipitation in a number of regions
* 3-10 percent increases in heavy rainfall
* 5-15 percent yield reductions of a number of crops
* 5-10 percent changes in streamflow in many river basins worldwide
* About 15 percent and 25 percent decreases in the extent of annually averaged and September Arctic sea ice, respectively

For warming of 2°C to 3°C, summers that are among the warmest recorded or the warmest experienced in people’s lifetimes, would become frequent.
For warming levels of 1°C to 2°C, the area burned by wildfire in parts of western North America is expected to increase by 2 to 4 times for each degree (°C) of global warming.

Many other important impacts of climate change are difficult to quantify for a given change in global average temperature, in part because temperature is not the only driver of change for some impacts; multiple environmental and other human factors come into play. It is clear from scientific studies, however, that a number of projected impacts scale approximately with temperature. Examples include shifts in the range and abundance of some terrestrial and marine species, increased risk of heat-related human health impacts, and loss of infrastructure in the coastal regions and the Arctic.


The report demonstrates that stabilizing atmospheric carbon dioxide concentrations will require deep reductions in the amount of carbon dioxide emitted. Because human carbon dioxide emissions exceed removal rates through natural carbon “sinks,” keeping emission rates the same will not lead to stabilization of carbon dioxide. Emissions reductions larger than about 80 percent, relative to whatever peak global emissions rate may be reached, are required to approximately stabilize carbon concentrations for a century or so at any chosen target level (see Figure ES.3).

But stabilizing atmospheric concentrations does not mean that temperatures will stabilize immediately. Because of time-lags inherent in the Earth’s climate, warming that occurs in response to a given increase in the concentration of carbon dioxide (“transient climate
change”) reflects only about half the eventual total warming (“equilibrium climate change”) that would occur for stabilization at the same concentration (see Figure ES.2). For example, if concentrations reached 550 ppmv, transient warming would be about 1.6°C, but holding concentrations at 550 ppmv would mean that warming would continue over the next several centuries, reaching a best estimate of an equilibrium warming of about 3°C.

Estimates of warming are based on models that incorporate ‘climate sensitivities’—the amount of warming expected at different atmospheric concentrations of carbon dioxide (Table 1). Because there are many factors that shape climate, uncertainty in the climate sensitivity is large; the possibility of greater warming, implying additional risk, cannot be ruled out, and smaller warmings are also possible. In the example given above, choosing a concentration target of 550 ppmv could produce a likely global warming at equilibrium as low as 2.1°C, but warming could be as high as 4.3°C, increasing the severity of impacts.

Thus, choices about stabilization targets will depend upon value judgments regarding the degree of acceptable risk.

GHG Legislation Efforts Abandoned (again)

From today’s Washington Post:  “Conceding that they can’t find enough votes for the legislation, Senate Democrats on Thursday abandoned efforts to put together a comprehensive energy bill that would seek to curb greenhouse gas emissions . . .” 

Hardly surprising, but disappointing nonetheless.

Research Needs for Solar Radiation Management (Climate Geoengineering)

Professor David Keith of the University of Calgary is both a scientist actively engaged in climate geoengineering research (primarily air capture technology) and one of the most thoughtful voices on ethical and governance considerations. Instructors seeking a good reading on geoengineering should check out Professor Keith’s February testimony before the House Energy and Environment Subcommittee of the Committee on Science and Technology. While Keith’s testimony focuses on solar radiation management (SRM) geoengineering technologies, virtually all of his remarks are equally opposite to other geoengineering approaches also.

Among the take-aways from Dr. Keith’s testimony:

  1. Development of SRM technologies should be as transparent as possible, including the banning of commercial or proprietary work;
  2. While the risk of SRM creating a moral hazard (i.e. reducing political will to reduce greenhouse gas emissions) may exist, the potential advantages outweigh this consideration given potential ” for unlikely but rapid and high-consequence climate impacts;”
  3. An expenditure of $10 billion annually could roughly exert enough of a cooling effect to counteract the heating from a doubling of atmospheric levels of carbon dioxide;
  4. Potential environmental impacts of SRM can’t be assessed without field testing, though this can be restricted to releasing tons of sulfur or other particles rather than megatons.
  • Research programs should start slowly, lest excessive funding fuel development of “ill conceived” projects, which could also engender a backlash that could doom systematic research
  • A U.S.  research program should draw upon the expertise of a number of agencies, because no one agency would have the expertise to conduct such a program. Potential pertinent agencies would include NSF and NASA;
  • Given the controversial nature of geoengineering research, both proponents and adversaries should participate. One possible approach is the “blue team/red team” system used in military preparedness planning
  1. Beyond the research phase, there is the imposing issue of international governance given the potential for States, desperate to address an impending/ongoing climatic crisis, a State might choose to inject sulfur into the amtosphere without prior risk assessment or international consultation;
  2. International cooperation should be built from the bottom up, in the same manner  that the treaty on landmines grew out of initiatives by NGOs. Hasty pursuit of an international regulation could result in total ban on research or “burdensome vetting of even innocuous research projects”

Keith’s testimony could generate some good class discussion. Some potential questions include:

  • Do the students agree that SRM initiatives should be developed from the bottom up, or would it be better to seek to develop an international regulatory framework at the outset? Is the landmine treaty a relevant instrument for comparison?
  • Do the students agree that the threat of climate change outweighs the potential moral hazards of geoengineering schemes?
  • Keith alludes to potential environmental impacts of SRM; what are some of these impacts and how would be address them in the context of an international regulatory framework?

    Post-Copenhagen Assessment

    I have always found the open access publication Tiempo to be an excellent source of information on climate issues, as well a good source of student readings. For instructors looking for a good assessment of developments since the 15th COP at Copenhagen, the April edition has a very good article that surveys opinions in developing and developed Party States, as well as the corporate and NGOs sectors.

    Among the article’s take-aways:

    1. The EU’s frustration with the UN negotiating framework has resulted in efforts to make greater use of informal bodies e.g. the Major Economies Forum and G20;
    2. There is substantial friction between the EU and China, with the EU accusing China of vetoing references to specific 2050 emissions targets at COP15 and China labeling this as “plainly a political scheme;”
    3. While it has been estimated that at least $25 billion annually would be needed to launch a REDD (Reducing Emissions from Deforestation in Forest Degradation in Developing Countries) program, to date only $3.5 billion has been committed to preparatory work over the coming three years;
    4. The carbon market responded to the Copenhagen Accord with an immediate 10% drop in the price of EU-ETS permits, with many citing inadequate drivers for stimulating the carbon market or innovative technologies;
    5. The BASIC (Brazil, South Africa, India and China) countries are mobilizing to provide assistance (scientific cooperation and technological support) to other developing countries, with Brazil’s environmental minister asserting that BASIC countries would provide support that would top the $10 billion of annually support pledged by developed countries for 2010-2012 (the so-called “fast start” funding);
    6. One of the primary tension points at the Bonn intersessional meeting in April was the relationship of the twin negotiating tracks of the Ad Hoc Working Group for Long-Term Cooperative Action under the UNFCCC and the Ad-Hoc Working Group under the Kyoto Protocol.

    Effectiveness and Consequences of Carbon Dioxide Capture and Sequestration

    With coal likely to continue to play a very substantial role in energy production over the course of the next few decades, with critical implications for climate policy making, there has been substantial focus in many quarters on the prospects for carbon capture and sequestration (CCS). However, a new study in the journal Nature Geoscience, Gary Shaffer, Long-Term Effectiveness and Consequences of  Carbon Dioxide Sequestration, 3 Nature Geoscience 464-467 (2010) (subscription required) should serve as a cautionary tale for these prospects. This would be a good reading at the graduate school or law school level.

    Among the key take-aways from the study, which makes long-term projections of the potential of CCS using the Danish Center for Earth System Science model:

    1. Under the IPCC A2 scenario, total gross and net emissions in the simulation were 3,721 GtC and 822 GtC, with 2,899 GtC sequestered over two centuries. While this is “immense” sequestration, it doesn’t exceed geological storage capacity;
    2. In assessing seve3ral different storage/leakage scenarios, the authors concluded:
    • Ocean storage between 2500-3500 meters: much of the initial warming is mitigated, but it still exceeds some IPCC projections by about 1C because of greater net radiative forcing from non-CO2 greenhouse gases. Ocean storage also leads to a mean pH decrease at 3000 meters of more than one unit and a mean pCO2 increase at this depth of almost 7000ppm; both these factors could have negative impacts on deep-sea life. Additionally, while atmospheric warming drops slightly after an initial warming peak, it rises again to 3.5C by 4000 as some sequestered carbon dioxide leaks;
    • Onshore geological storing yields several potential scenarios:
      • Under a rapidly leaking projection of carbon dioxide, atmospheric warming would exceed those of even the A2 projection with no sequestration;
      • Under a moderating leaking projected ocean warming, acidification and dead zone volume exceed those of A2 projections;
      • In a weakly leaking projection, atmospheric warming would decrease rapidly to levels slightly above present-day global warming;
      • In a best case projection with no leakage from geological storage, relevant indicators would converge to very near AG projection after several hundred years.
    • Carbon dioxide storage would have to last for tens of thousands of years to avoid strong, delayed warming and vast expansion of ocean dead zones, much longer than the 4000 years projected by previous studies. Deep-ocean sequestration can’t meet this storage criterion. Moreover, a leakage rate of 1% or less per thousand years from an underground storage reservoir would be required to maintain conditions close to low-emission projections with no sequestration. Another possible option would be continuous re-sequestration; however this process would have to be carried on for thousands of years, much like the burden imposed by storing spent nuclear fuel.

    CCS, even if concerns about energy use and economic viability can be overcome, thus faces some serious questions about the technological viability of minimizing leakage to extremely minimal levels, and imposing this task on many generations to come. The ethics of this approach vis-a-vis alternatives could stimulate some very good classroom discussion.