AMS Draft Statement on Geoengineering the Climate System

[Dan Whaley]

The AMS Draft Statement on Geoengineering the Climate System is
available via the AMS home page now...

If you have comment on this draft AMS Statement currently under
consideration, you may transmit those comments to the AMS Council by
sending a message to the following e-mail address by April 23 2009:
statement...@ametsoc.org

http://www.ametsoc.org/POLICY/draftstatements/geoengineering_draftstatement.pdf

AMS Policy Statement on Geoengineering the Climate System
Draft 7 March 2009

Human activities have very likely caused most of the well-documented
change in global climate over the last half century. Unchecked future
greenhouse gas emissions, particularly of carbon dioxide from the
burning of fossil fuels, will almost certainly lead to additional
climate impacts such as further global warming, continued sea level
rise, greater rainfall intensity, more serious and pervasive droughts,
enhanced heat stress episodes, ocean acidification, and the disruption
of many biological systems. The resulting inundation of coastal areas,
severe weather impacts, and loss of ecosystem services will likely
cause major negative impacts for most nations.

Three strategies could potentially help reduce the risks of climate
change: 1) reduce emissions (mitigation), 2) moderate impacts by
increasing our capacity to cope with them (adaptation), and 3)
deliberately manipulate large-scale physical, chemical, or biological
aspects of the climate system to counteract the climate effects of
increasing greenhouse gas emissions (geoengineering the climate
system). This policy statement addresses geoengineering.

Geoengineering could conceivably offer targeted and fast-acting
options to reduce acute climate impacts and provide strategies of last
resort if abrupt, catastrophic, or otherwise unacceptable climate
change impacts become unavoidable by other means. However,
geoengineering must be viewed with great caution because manipulating
the Earth system is almost certain to trigger some adverse and
unpredictable consequences. Furthermore, these impacts would almost
certainly be distributed unevenly among nations and people, raising
serious ethical issues. Research to date has not determined that there
are large-scale geoengineering approaches for which the benefits would
substantially outweigh the detriments.

Geoengineering proposals fall into at least three broad categories: 1)
managing atmospheric greenhouse gases (e.g., ocean fertilization and
atmospheric carbon capture and sequestration), 2) cooling the Earth by
reflecting sunlight (e.g., putting reflective particles into the
atmosphere, putting mirrors in space to reflect the sun’s energy,
increasing surface reflectivity, and altering the amount or
characteristics of clouds), and 3) moderating specific impacts of
global warming (e.g., efforts to limit sea level rise by increasing
land storage of water, protecting ice sheets, or artificially
enhancing mountain glaciers).

Geoengineering proposals differ widely in their potential to reduce
impacts, create new risks, and redistribute risk among nations. For
example, reflecting sunlight would likely reduce the Earth’s average
temperature but could also change global circulation with potentially
serious consequences such as changing storm tracks and precipitation
patterns throughout the world. As with inadvertent human-induced
climate change, the consequences of such actions would almost
certainly not be the same for all nations and individuals, thus
raising legal, ethical, diplomatic, and even national security
concerns.

Exploration of geoengineering strategies also creates potential risks.
Developing any new capacity will require resources, possibly drawn
from more productive uses. The possibility of quick and seemingly
inexpensive geoengineering fixes could distract the public and policy
makers from critically needed efforts to reduce greenhouse gas
emissions and build society’s capacity to deal with unavoidable
climate impacts. Geoengineering technologies, once developed, may
enable short-sighted and unwise deployment, with potentially serious
unforeseen consequences.

Even if reasonably effective and beneficial overall, none of the
geoengineering approaches proposed to date would alleviate all of the
serious impacts from increasing greenhouse gas emissions. For example,
enhancing solar reflection would not alleviate direct effects of the
rise in CO2 concentration such as ocean acidification or changes to
the structure and function of biological systems.

Still, the threat of climate change is serious. Mitigation efforts so
far have been limited in magnitude, tentative in implementation, and
insufficient for slowing climate change enough to avoid potentially
serious societal impacts. Not all of the expected climate change
impacts can be managed through adaptation. Thus, it is prudent to
consider geoengineering’s potential, to understand its limits, and to
avoid rash deployment.

Therefore, the American Meteorological Society recommends:
1) Enhanced research on the scientific and technological potential for
geoengineering the climate system, including research on the
unintended as well as intended environmental responses.
2) Additional study of the historical, ethical, legal, political, and
societal aspects of the geoengineering issues.
3) Development and analysis of policy options to promote transparency
and international cooperation in exploring geoengineering options
along with restrictions on reckless efforts to manipulate the climate
system.

Geoengineering will not substitute for either aggressive mitigation or
proactive adaptation. It could contribute to a comprehensive risk
management strategy to slow climate change and alleviate its negative
impacts, but the potential for adverse and unintended consequences
implies a need for adequate research, appropriate regulation, and
transparent consideration.