Stratospheric Aerosols for Solar Radiation Management
SRM in the context of this entry involves placing a large amount of aerosols in the stratosphere to reduce the amount of solar radiation reaching the surface, thereby cooling the surface and counteracting some of the warming from anthropogenic greenhouse gases. The way this is accomplished depends on the specific aerosol used, but the basic mechanism involves backscattering and absorbing certain amounts of solar radiation aloft. Since warming from greenhouse gases is due to longwave (thermal) emission, compensating for this warming by reduction of shortwave (solar) energy is inherently imperfect, meaning SRM will have climate effects that are different from the effects of climate change. This will likely manifest in the form of regional inequalities, in that, similarly to climate change, some regions will benefit from SRM, while some will be adversely affected, viewed both in the context of present climate and a climate with high CO2 concentrations. These effects are highly dependent upon the means of SRM, including the type of aerosol to be used, the particle size and other microphysical concerns, and the methods by which the aerosol is placed in the stratosphere. SRM has never been performed, nor has deployment been tested, so the research up to this point has serious gaps. The amount of aerosols required is large enough that SRM would require a major engineering endeavor, although SRM is potentially cheap enough that it could be conducted unilaterally. Methods of governance must be in place before deployment is attempted, should deployment even be desired. Research in public policy, ethics, and economics, as well as many other disciplines, will be essential to the decision-making process. SRM is only a palliative treatment for climate change, and it is best viewed as part of a portfolio of responses, including mitigation, adaptation, and possibly CDR. At most, SRM is insurance against dangerous consequences that are directly due to increased surface air temperatures.
- Arctic oscillation
A pattern of sea-level pressures in the Arctic indicating large-scale circulation patterns. This serves as a proxy for the degree to which Arctic air penetrates to lower latitudes. During a positive mode of the Arctic Oscillation, which occurs both naturally and can be forced by large injections of stratospheric aerosols that enhance the polar jets, cold air gets trapped in the Arctic, resulting in warmer winter temperatures over the northern hemisphere continents.
- Carbon dioxide removal (CDR)
Removing carbon dioxide from the atmosphere and sequestering it, either in geological formations or in the deep ocean, thereby decreasing the atmospheric concentration of anthropogenic greenhouse gases.
A convective cloud that forms from a large amount of heating, and subsequent rising air, created by large fires.
- Solar radiation management (SRM)
Reducing the amount of sunlight incident at the surface, thereby decreasing the globally averaged surface air temperature of the planet.
- Stratospheric aerosols
A layer of aerosols into the stratosphere which either scatter or absorb (or a combination of the two) a certain portion of sunlight that would, under normal circumstances, reach the surface.
- Tipping point
The point at which global climate transitions from one stable state to another. Some extreme examples include ice ages, in which the climate rapidly cools, forming large ice sheets. The climate in this state is relatively stable, mainly due to an increase in planetary albedo, and is not easily returned to a different state (the present day climate, for example) without a large forcing of some kind.
- 1.Intergovernmental Panel on Climate Change (IPCC) (2007) Climate change 2007: the fourth assessment report of the intergovernmental panel on climate change. Cambridge University Press, 996 ppGoogle Scholar
- 10.ETC (2010) Stop geoengineering – our home is not a laboratory! http://www.etcgroup.org/upload/publication/pdf_file/HOMEBriefingENGsm.pdf. Accessed 30 Oct 2011
- 11.Stern N (2006) The economics of climate change: the stern review. Executive summary, Her Majesty’s treasury, London, 27 pp. http://siteresources.worldbank.org/INTINDONESIA/Resources/226271-1170911056314/3428109-1174614780539/SternReviewEng.pdf. Accessed 30 Oct 2011
- 12.Fleming JR (2010) Fixing the sky: the checkered history of weather and climate control. Columbia University Press, New York, 344 ppGoogle Scholar
- 13.von Neumann J (1955) Can we survive technology? Fortune 106–108:151–152Google Scholar
- 14.Budyko MI (1974) Climate and life. Academic, New York, 508 ppGoogle Scholar
- 16.National Academy of Sciences (NAS) (1992) Policy implications of greenhouse warming: mitigation, adaptation, and the science base. National Academy Press, Washington, DC, pp 433–464Google Scholar
- 19.Teller E, Wood L, Hyde R (1997) Global warming and ice ages: I. Prospects for physics-based modulation of global change. U.S. Department of Energy, Lawrence Livermore National Laboratory, UCRL-JC- 128715, 18 ppGoogle Scholar
- 20.Teller E, Caldeira K, Canavan G, Govindasamy B, Grossman A, Hyde R, Ishikawa M, Ledebuhr A, Leith C, Molenkamp C, Nuck-olls J, Wood L (1999) Long-range weather prediction and prevention of climate catastrophes: a status report. U.S. Department of Energy, Lawrence Livermore National Laboratory, UCRL-JC-135414, 42 ppGoogle Scholar
- 21.Teller E, Hyde R, Wood L (2002) Active climate stabilization: Practical physics-based approaches to prevention of climate change. U.S. Department of Energy, Lawrence Livermore National Laboratory, 8 ppGoogle Scholar
- 23.Khan E, Ferrell W, MacCracken MC, Schwartz SE, Duffy PB, Thompson S, Marland GH (2001) Response options to limit rapid or severe climate change. U.S Department of Energy, Washington, DC, 37 ppGoogle Scholar
- 31.Kravitz B, Robock A, Boucher O, Schmidt H, Taylor KE, Stenchikov G, Schulz M (2011) The geoengineering model inter-comparison project (GeoMIP). Atm Sci Lett 12:162167. doi:10.1002/asl.316Google Scholar
- 35.Shepherd J, Caldeira K, Cox P, Haigh J, Keith D, Launder B, Mace G, MacKerron G, Pyle J, Rayner S, Redgwell C, Watson A (2009) Geoengineering the climate: science, governance and uncertainty. Royal Society Policy document 10/09, 82 ppGoogle Scholar
- 38.Lacis AA, Mishchenko MI (1995) Climate forcing, climate sensitivity, and climate response: a radiative modeling persepctive on atmospheric aerosols. In: Charlson RJ, Heintzenberg J (eds) Aerosol forcing of climate: report of the Dahlem workshop on aerosol forcing of climate, Berlin, 24–29 April 1994. Wiley, Chichester/New YorkGoogle Scholar
- 40.Lane L, Caldeira K, Chatfield R, Langhoff S (2007) Workshop report on managing solar radiation. National Aeronautics and Space Administration, NASA/CP-2007-214558, 31 ppGoogle Scholar
- 41.Jones A, Haywood J, Boucher O, Kravitz B, Robock A (2010) Geoengineering by stratospheric SO2 injection: results from the Met Office HadGEM2 climate model and comparison with the Goddard Institute for Space Studies ModelE. Atm Chem Phys 10:5999–6006. doi:10.5194/acp-10-5999-2010ADSCrossRefGoogle Scholar
- 42.Chapman S (1930) On ozone and atomic oxygen in the upper atmosphere. Philos Mag 10:369–383Google Scholar
- 46.Kinnison DE, Grant KE, Connell PS, Rotman DA, Wuebbles DJ (1994) The chemical and radiative effects of the Mount Pinatubo eruption. J Geophys Res 99:2570525731. doi:10.1029/94JD02318Google Scholar
- 51.Keeling CD, Piper SC, Bacastow RB, Wahlen M, Whorf TP, Heimann M, Meijer HA (2001) Exchanges of atmospheric CO2 and 13CO2 with the terrestrial biosphere and oceans from 1978 to 2000, vol I. Scripps Institution of Oceanography, San Diego Global aspects, SIO Reference Series, No. 01–06, 88ppGoogle Scholar
- 57.McClellan J, Sisco J, Suarez B, Keogh G (2010) Geoengineering cost analysis. Aurora Flight Sciences, AR10-182, 86 ppGoogle Scholar
- 58.Kravitz B (2011), Stratospheric geoengineering with black carbon aerosols, Dissertation thesis, available online at http://www.stanford.edu/~bkravitz/research/papers/other/kravitzthesisfinal.pdf
- 62.Crutzen PJ, Birks JW (1982) Atmosphere after a nuclear war: Twilight at noon. Ambio 11(2/3):114–125Google Scholar
- 64.Aleksandrov VV, Stenchikov GL (1983) On the modeling of the climatic consequences of the nuclear war. In: The proceedings of applied mathematics, The Computing Centre of the USSR Academy of Sciences, Moscow, 21 ppGoogle Scholar
- 66.Pittock AB, Ackerman TP, Crutzen PJ, MacCracken MC, Shapiro CS, Turco RP (eds) (1986) Environmental consequences of nuclear war, SCOPE 28, vol I. Wiley, New York, Physical and Atmospheric EffectsGoogle Scholar
- 72.CDC (1999) Elemental carbon (diesel particulate): Method 5040, Issue 3 (Interim), National Institute for Safety and Health, Centers for Disease Control and Prevention. In: NIOSH manual of analytical methods, 4th rev. edn., 5 pp. http://www.cdc.gov/niosh/docs/2003-154/pdfs/5040f3.pdf. Accessed 30 Oct 2011
- 82.Llewellyn EJ, Lloyd ND, Degenstein DA, Gattinger RL, Petelina SV, Bourassa AE, Wiensz JT, Ivanov EV, McDade IC, Solheim BH, McConnell JC, Haley CS, von Savigny C, Sioris CE, McLinden CA, Griffioen E, Kaminski J, Evans WFJ, Puckrin E, Strong K, Wehrle V, Hum RH, Kendall DJW, Matsushita J, Murtagh DP, Brohede S, Stegman J, Witt G, Barnes G, Payne WF, Piché L, Smith K, Warshaw G, Deslauniers D-L, Marchand P, Richardson EH, King RA, Wevers I, McCreath W, Kyrölä E, Oikarinen L, Leppelmeier GW, Auvinen H, Mégie G, Hauchecorne A, Lefévre F, de La Nöe J, Ricaud P, Frisk U, Sjoberg F, von Schéele F, Nordh L (2004) The OSIRIS instrument on the Odin spacecraft. Can J Phys 82(6):411–422. doi:10.1139/p04?005ADSCrossRefGoogle Scholar