Oslo joint seminar in atmospheric, ocean and climate science, Apr. 15

Title: Stratospheric Sulfur Geoengineering – Benefits and Risks

Speaker:   Alan Robock, Rutgers University

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Speaker: Alan Robock, Rutgers University


Geoengineering, also called climate engineering or climate intervention, has been proposed as a “solution” to global warming, involving “solar radiation management” by injecting particles into the stratosphere, brightening clouds, or blocking sunlight with satellites between the Sun and Earth.  While volcanic eruptions have been suggested as innocuous examples of sulfate stratospheric aerosols cooling the planet, the volcano analog actually illustrates many potential risks of stratospheric geoengineering, including of ozone depletion and regional hydrologic responses.  No such systems to conduct stratospheric geoengineering now exist, but the least expensive option would probably be to invent airplanes that could put sulfur gases into the stratosphere.  Nevertheless, it may be very difficult to create stratospheric sulfate particles with a desirable size distribution.

Our Geoengineering Model Intercomparison Project, conducting climate model experiments with standard stratospheric aerosol injection scenarios, is ongoing.  I will show results from several of our experiments.  We have found that if there were a way to continuously inject SO2 into the lower stratosphere, it would produce global cooling, stopping melting of the ice caps, and increasing the uptake of CO2 by plants.  But there are at least 27 reasons why stratospheric geoengineering may be a bad idea.  These include disruption of the Asian and African summer monsoons, reducing precipitation to the food supply for billions of people; ozone depletion; no more blue skies; reduction of solar power; and rapid global warming if it stops, with devastating impacts on natural ecosystems.  Furthermore, there are concerns about commercial or military control, and it may seriously degrade terrestrial astronomy and satellite remote sensing.  Global efforts to stop anthropogenic emissions of greenhouse gases (mitigation) and to adapt to climate change are needed no matter what, if we choose to prevent dangerous anthropogenic interference with the climate system.  Whether implementation of stratospheric geoengineering would be make the situation more dangerous needs to be answered by ongoing research.

What is the Joint Oslo Seminar (JOS):

Atmospheric and climate sciences have a stronghold in Oslo among the four institutions University of Oslo, the Meteorological Institute, CICERO and NILU. This joint seminar invites renowned international experts to contribute to an informal series of lectures, meant to create interaction with the Oslo atmospheric and climate science community on recent highlights and analysis in the field. All seminars will be held on Thursdays (Noon -1pm).

Published Jan. 29, 2021 3:47 PM - Last modified Apr. 7, 2021 3:19 PM