Download Geoengineering for Decision Makers, by Robert Olson, from the Wilson Center. Excerpted below is the executive summary.
Geoengineering involves intentional, large-scale interventions in the Earth’s atmosphere, oceans, soils or living systems to influence the planet’s climate. Geoengineering is not a new idea
. Speculation about it dates at least to 1908, when Swedish scientist Svente Arrhenius suggested that the carbon dioxide released from burning fossil fuels might help prevent the next ice age. Until recently, proposals for using geoengineering to counteract global warming have been viewed with extreme skepticism, but as projections concerning the impact of climate change have become more dire
, a growing number of scientists have begun to argue that geoengineering deserves a second look.
Below are 10 of the major concerns about geoengineering that policymakers need to be aware of and give due consideration. These concerns apply mainly to solar radiation management (SRM), the form of geoengineering that attempts to cool the climate by reflecting a small amount of solar radiation back into space. SRM involves significantly higher risks than the other form of geoengineering, carbon dioxide removal (CDR) which involves removing carbon dioxide from the atmosphere and storing it in the ocean, plants, soil, or geological formations.
As problematic as geoengineering is, a growing number of scientists now view global climate change as such a serious threat that they feel no option for dealing with it, including geoengineering, can be taken off the table. There is no longer any doubt that the average temperature of the Earth’s atmosphere and oceans is rising. There is an overwhelming consensus in the scientific community that human activities are significant contributors to this temperature increase, even if other dynamics are also at work. There are still uncertainties about how fast the climate will change and even larger uncertainties about the impacts climate change could have in different parts of the world. But there is substantial agreement that the impacts could become dangerous over the decades ahead. The greatest danger is that we could pass “tipping points” of self-amplifying, irreversible change into a much hotter world.
- Unintended Negative Consequences: We may know too little about the Earth’s geophysical and ecological systems to be confident we can engineer the climate on a planetary scale without making an already bad situation even worse;
- Potential Ineffectiveness: Some proposed CDR methods are so weak that they would produce useful results only if sustained on a millennial timescale;
- Risk of Undermining Emissions-Mitigation Efforts: If politicians come to believe that geoengineering can provide a low-cost “tech fix” for climate change, it could provide a perfect excuse for backing off from efforts to shift away from fossil fuels;
- Risk of Sudden Catastrophic Warming: If geoengineering is used as a substitute for emissions reduction, allowing high concentrations of CO2 to build up in the atmosphere, it would create a situation where if the geoengineering ever faltered because of wars, economic depressions, terrorism or any other reasons during the millennium ahead, a catastrophic warming would occur too quickly for human society and vast numbers of plant and animal species to adapt;
- Equity Issues: Geoengineering efforts might succeed in countering the warming trend on a global scale, but at the same time cause droughts and famines in some regions;
- Difficulty of Reaching Agreement: It could be harder to reach global agreements on doing geoengineering than it is to reach agreements on reducing carbon emissions;
- Potential for Weaponization: Geoengineering research could lead to major advances in knowledge relevant for developing weather control as a military tool;
- Reduced Efficiency of Solar Energy: For every one percent reduction in solar radiation caused by the use of SRM geoengineering, the average output of concentrator solar systems that rely on direct sunlight will drop by four to five percent;
- Danger of Corporate Interests Overriding the Public Interest: Dangers include a lack of transparency in SRM technology development and the possibility that the drive for corporate profits could lead to inappropriate geoengineering deployments;
- Danger of Research Driving Inappropriate Deployment: Research programs have often created a community of researchers that functions as an interest group promoting the development of the technology that they are investigating.
Several of the best climate studies suggest that stabilizing the amount of carbon dioxide and other greenhouse gases below the level that risks dangerous climate change will require a social mobilization and technological transformation at a speed and scale that has few if any peacetime precedents. If correct, and the needed mobilization does not occur in the years immediately ahead, then decision makers later in the century could find themselves in a situation where geoengineering is the only recourse to truly dangerous climate change. The most fundamental argument for R&D; on geoengineering is that those decision makers should not be put in a position of either letting dangerous climate change occur or deploying poorly evaluated, untested technologies at scale. At the very least, we need to learn what approaches to avoid even if desperate.
Continue reading by downloading the full report from the Wilson Center.
Robert Olson is a Senior Fellow at the Institute for Alternative Futures.