PRESIDENT'S LETTER

Rick Amasino

Energy and Plant Biology

The recent release of the report on the economics of climate change commissioned by the British government ([1]; often referred to as the Stern Review) underscores the urgency of addressing the issue of human-caused increasing atmospheric CO₂ concentration. Before the industrial revolution, CO₂ levels were 280 ppm; the current level is over 400 ppm. The Stern Review (and many other reviews) note that if we continue on our present course, the CO₂ equivalent levels (2) could approach 600 ppm by 2035 and that if CO₂ equivalent levels are not stabilized at the 450–550 ppm level, the consequences could be quite severe (for a review of those consequences, see the Stern Review or an apocalyptic 2003 report [3a] [3b] prepared for the Pentagon). Furthermore, if we do not act now, the opportunity to stabilize at even 550 ppm is likely to “slip away” (1). Long-term stabilization will require that CO₂ emissions ultimately be reduced “to more than 80% below current levels” (1); such a reduction will require major changes in how we operate.

A major focus of the Stern Review is economics. (A concise and interesting perspective on climate change and economics was recently written by Joseph Stiglitz, an economist who won the Nobel prize in 2001 [4].) The Stern Review notes that the implementation of measures to achieve the reductions required for stabilization are a “major challenge,” but, if we act quickly, stabilization can be achieved “at costs that are low in comparison to the risks of inaction.” One of the reasons there has not been much progress to date is that “climate change is the greatest market failure the world has ever seen” (1). Market failure refers to the failure to pay the long-term costs of releasing CO₂. Indeed, with the exception of Boulder, Colorado, whose citizens recently approved a carbon tax (5), there are no costs in the United States for using the atmosphere as waste dump for CO₂. The atmosphere is being used as a “commons” in the sense discussed by Hardin in the essay “The Tragedy of the Commons” (6). This market failure is not surprising: Markets are driven solely by economic factors, and unless markets are required to incorporate long-term global costs, they will not do so. There are signs of change; for example, in a case now before the Supreme Court, 12 states are suing the Environmental Protection Agency for not regulating CO₂ emissions (7a) (7b).

Plants are, of course, a carbon-neutral source of energy that could make a contribution to atmospheric stabilization. But we need to be realistic with respect to the contributions that certain plant-based approaches can provide. For example, if the entire U.S. crop of corn grain was converted into ethanol, it would meet approximately 15 percent of our current transportation fuel needs (8). And despite Willie Nelson’s enthusiasm (9), our entire vegetable oil crop would provide much less fuel than corn grain. Clearly, if the United States had not retreated from policies that mandated and encouraged conservation, we might currently be saving more fuel than that which could be produced with existing technologies from our current total corn and vegetable oil outputs.

As ASPB members know, the most abundant source of plant-derived energy is where most of the fixed carbon is deposited—the cell wall. A recent report from the Department of Energy, “Breaking the Biological Barriers to Cellulosic Ethanol” (8), provides a quantitative assessment of the significant contribution that cell wall biomass could make to our energy budget. A key issue discussed in the report is whether efficient technologies can be developed to convert cell wall material into fuels. Progress is likely to result from a combination of plant breeding, plant and microbial metabolic engineering, and chemical engineering. On the plant side of the equation, for example, a promising approach is the development of ways to modify cell wall composition to create a “feedstock” that is more readily converted into fuels. Of course, stabilization of CO₂ levels will require progress on multiple fronts. When there are breakthroughs in the conversion of cell wall biomass to fuels, a combination of conservation and increased utilization of other renewable energy sources, such as wind, photovoltaics, and solar heating, to name but a few, will also be required.

Richard Amasino
amasino@biochem.wisc.edu

REFERENCES

1. The Stern Review can be obtained at http://www.sternreview.org.uk. The Executive Summary of the Stern Review provides a concise overview: http://www.hm-treasury.gov.uk/ media/8AC/F7/Executive_Summary.pdf.
   
   
2. CO₂ equivalent level refers to the radiative effects of a certain level of CO₂; for example, the effects of other heat-trapping atmospheric gases such as methane can be expressed as CO₂ equivalents.
   
   
3. Article on the report at http://observer.guardian.co.uk/international/story/0,6903,1153513,00.html; actual report at http://www.environmentaldefense.org/
   documents/3566_AbruptClimateChange.pdf.
   
   
4. Joseph Stiglitz. (2006). A new agenda for global warming. The Economists’ Voice 3(7): Article 3. http://www.bepress.com/ev/vol3/iss7/art3/. (The Nobel prize in economics is formally the Sveriges Riksbank Prize in Economic Sciences in Memory of Alfred Nobel.)
   
   
5. Katie Kelley. (2006). City approves “carbon tax” in effort to reduce gas emissions. New York Times, November 18. http://www.nytimes.com/2006/11/18/us/ 18carbon.html?th&emc=th.
   
   
6. Garrett Hardin. (1968). The tragedy of the commons. Science 162: 1243–1248. DOI: 10.1126/science.162.3859.1243; http://www.sciencemag.org/cgi/content/full/162/3859/1243.
   
   
7. Juliet Eilperin. (2006). High court to hear greenhouse gas case. Washington Post, June 27, A05. http://www.washingtonpost.com/wp-dyn/content/article/2006/06/26/ AR2006062600399.html.
   Global warming goes to court (Editorial). (2006). New York Times, November 28. http://www.nytimes.com/2006/11/28/opinion/28tue1.html?th&emc=th.
   
   
8. Breaking the biological barriers to cellulosic ethanol. http://genomicsgtl.energy.gov/biofuels/b2bworkshop.shtml.
   
   
9. Willie Nelson’s Biodeisel website: http://www.wnbiodiesel.com/.

Note added in proof: The Intergovernmental Panel on Climate Change released an important report on Friday, February 2, 2007. “Climate Change 2007: The Physical Science Basis” is available at http://www.ipcc.ch/SPM2feb07.pdf.