With a mere four months remaining before the international community begins negotiations on a global plan to reduce greenhouse gas (GHG) emissions in Copenhagen, a small group of researchers are challenging the notion that a reduction in GHG emissions is the only sensible and cost-effective approach to solving the problem of global climate change.
In a new report released last week—An Analysis of Climate Engineering as a Response to Climate Change—Eric Bickel and Lee Lane consider the role that climate engineering (also known as geoengineering) could play in preventing global climate change. Contrasting the prevailing policy belief that the only way to achieve this objective is to reduce global GHG emissions, Bickel and Lane consider two alternatives—Solar Radiation Management and Air Capture—that involve large-scale technological interventions to mitigate the climate-changing effect of GHGs in the atmosphere.
Solar Radiation Management (SRM) seeks to lower the amount of solar radiation absorbed by the Earth’s atmosphere. As the authors write, “SRM does not attach the underlying cause of the warming, higher GHG concentrations. Rather it seeks to reflect back into space a small part of the Sun’s incoming short-wave radiation. In this way, temperatures are lowered even though GHG levels are elevated.” The authors suggest this may work based on analysis of the temperature effects of past volcanic eruptions.
Bickel and Lane also consider Air Capture (AC), a process that theoretically works by capturing carbon dioxide emissions within the atmosphere and storing them in land and/or sea based sinks. While somewhat similar to carbon capture and storage (CCS), AC removes GHG emissions from the atmosphere whereas CCS relies upon capturing CO2 from point sources, such as power plants and the tail pipes of automobiles.
So just how beneficial could these alternatives actually be if implemented? According to the report, they could have substantial benefits relative to the costs of actually implementing such proposals. Stratospheric aerosol injection, one possible tool for implementing SRM, could have a benefit-cost ratio near 25 to 1. Another way of implementing SRM is by marine cloud whitening, which could have a benefit-cost ratio of 5000 to 1. If this sounds too good to be true, it may be. The authors acknowledge caution should be used when reviewing these results, as “any assessment of SRM and AC will be limited by the current state of knowledge, the rudimentary nature of the concepts, and the lack of prior R&D efforts.”
Concerns about the analysis itself aside, just how politically feasible are these technologies? With H.R. 2454 already through the House and the Senate poised to consider the bill this fall (provided health-care doesn’t take up too much legislative effort) it seems like not very.
Even if the United States does not consider SRM or AC, it does not mean that they won’t play an important future role on the international stage. Nonetheless, that seems unlikely as well. With the UN conference in Copenhagen this December, many nations are going to want to take meaningful action to prevent global climate change. As a result, the idea that countries would willingly choose to take an approach that still requires much research (as Bickel and Lane admit) and one that likely seems outlandish to much of the public, and perhaps experts, seems dubious. If an international agreement can be reached in the near future, before uncertainties about benefits/cost and implementation of geoengineering proposals can be resolved, it seems that these possibilities will remain simply that, possibilities. Still, alternative perspectives can’t hurt, and might actually inform the upcoming debate in Copenhagen.