2009 APS April Meeting
Volume 54, Number 4
Saturday–Tuesday, May 2–5, 2009;
Denver, Colorado
Session Q7: Is Geoengineering a Possible Stop-Gap Measure to Rapid Climate Change?
10:45 AM–12:33 PM,
Monday, May 4, 2009
Room: Governor's Square 12
Sponsoring
Unit:
FPS
Chair: Barbara Levi, American Institute of Physics
Abstract ID: BAPS.2009.APR.Q7.2
Abstract: Q7.00002 : The Many Problems with Geoengineering Using Stratospheric Aerosols*
11:21 AM–11:57 AM
Preview Abstract
Abstract
Author:
Alan Robock
(Rutgers University)
In response to the global warming problem, there has been a recent renewed
call for geoengineering ``solutions'' involving injecting particles into the
stratosphere or blocking sunlight with satellites between the Sun and Earth.
While volcanic eruptions have been suggested as innocuous examples of
stratospheric aerosols cooling the planet, the volcano analog actually
argues against geoengineering because of ozone depletion and regional
hydrologic and temperature responses. In this talk, I consider the
suggestion to create an artificial stratospheric aerosol layer. No systems
to conduct geoengineering now exist, but a comparison of different proposed
stratospheric injection schemes, airplanes, balloons, artillery, and a space
elevator, shows that using airplanes would not be that expensive.
We simulated the climate response to both tropical and Arctic stratospheric
injection of sulfate aerosol precursors using a comprehensive
atmosphere-ocean general circulation model, the National Aeronautics and
Space Administration Goddard Institute for Space Studies ModelE. We
simulated the injection of SO$_{2}$ and the model converts it to sulfate
aerosols, transports them and removes them through dry and wet deposition,
and calculates the climate response to the radiative forcing from the
aerosols. We conducted simulations of future climate with the
Intergovernmental Panel on Climate Change A1B business-as-usual scenario
both with and without geoengineering, and compare the results. We found that
if there were a way to continuously inject SO$_{2}$ into the lower
stratosphere, it would produce global cooling. Acid deposition from the
sulfate would not be enough to disturb most ecosystems. Tropical SO$_{2}$
injection would produce sustained cooling over most of the world, with more
cooling over continents. Arctic SO$_{2}$ injection would not just cool the
Arctic. But both tropical and Arctic SO$_{2}$ injection would disrupt the
Asian and African summer monsoons, reducing precipitation to the food supply
for billions of people. These regional climate anomalies are but one of many
reasons why geoengineering may be a bad idea. I also discuss 19 other
reasons. Global efforts to mitigate anthropogenic emissions and to adapt to
climate change are a much better way to channel our resources to address
anthropogenic global warming.
*Supported by NSF grant ATM-0730452.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2009.APR.Q7.2