Geoengineering in the Southern Ocean?
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Alex Brown
Jul 20, 2015, 11:55:03 AM7/20/15
to p...@turi.org, Listserve UML Climate
Pam Eliason wrote:
Very interesting -- thanks! Previous proposals for "albedo modification" (brightening cloud cover) have considered injection of sulfate aerosols into the stratosphere with balloons, rockets and artillery. This is generally believed to be much cheaper and quicker than changing cloud cover in the troposphere, as well as much higher in risks of unintended consequences:
Another form of such "geoengineering" of our atmosphere proposes large-scale sequestration of atmospheric CO2 in the oceans. Much of the Southern Ocean is called "high nutrient, low chlorophyll (HNLC)" by oceanographers due to limited iron, a trace element necessary for photosynthesis. One strategy for geoengineering for sequestration of CO2 on the ocean floor proposes fertilization of HNLC regions of the world's oceans to produce prompt phytoplankton blooms that would presumably fix CO2 into ocean biomass that would eventually fall to the ocean floor to become limestone. A few studies have shown successful blooms and at least one wildcat entrepreneur took the idea onto the high seas and tried to claim a carbon sequestration credit. The result was a legal furor over violation of a 1972 treaty on dumping at sea. The company ran out of cash but its website is still active (http://planktos.com) .
Both the US National Academies of Science and the UK Royal Society recently released reports on geoengineering:
Both reports distinguish between carbon sequestration and "albedo modification" (brightening cloud cover) but the British Royal Society commission report emphasizes the fundamental need for a transition from fossil fuels to renewable energy, and contrasts relative safety of "Carbon Dioxide Removal (CDR)" with risks of "Solar Radiation Management (SRM)", but does recognize both as planetary engineering proposals and goes on to discuss the governance and control procedures necessary to begin research and development.
http://www.scientificamerican.com/article/tiny-ocean-plants-geoengineer-brighter-clouds/
The Southern Ocean has some of the thickest clouds on Earth, made brighter in the summertime by marine microbes living in the waters below, according to new research that combines satellite observations and computer modeling. In fact, bacteria and plankton drifting in the ocean produce particles that get whipped up into atmosphere where they seed cloud droplets, and in turn, the brighter clouds reflect more sunlight away from Earth.
Very interesting -- thanks! Previous proposals for "albedo modification" (brightening cloud cover) have considered injection of sulfate aerosols into the stratosphere with balloons, rockets and artillery. This is generally believed to be much cheaper and quicker than changing cloud cover in the troposphere, as well as much higher in risks of unintended consequences:
- https://en.wikipedia.org/wiki/Stratospheric_sulfate_aerosols_(geoengineering)
- https://en.wikipedia.org/wiki/Cloud_reflectivity_modification
Another form of such "geoengineering" of our atmosphere proposes large-scale sequestration of atmospheric CO2 in the oceans. Much of the Southern Ocean is called "high nutrient, low chlorophyll (HNLC)" by oceanographers due to limited iron, a trace element necessary for photosynthesis. One strategy for geoengineering for sequestration of CO2 on the ocean floor proposes fertilization of HNLC regions of the world's oceans to produce prompt phytoplankton blooms that would presumably fix CO2 into ocean biomass that would eventually fall to the ocean floor to become limestone. A few studies have shown successful blooms and at least one wildcat entrepreneur took the idea onto the high seas and tried to claim a carbon sequestration credit. The result was a legal furor over violation of a 1972 treaty on dumping at sea. The company ran out of cash but its website is still active (http://planktos.com) .
- https://en.wikipedia.org/wiki/High-Nutrient,_low-chlorophyll
- https://en.wikipedia.org/wiki/Iron_fertilization
- http://www.nature.com/news/ocean-fertilization-project-off-canada-sparks-furore-1.11631
Both the US National Academies of Science and the UK Royal Society recently released reports on geoengineering:
- http://nas-sites.org/americasclimatechoices/public-release-event-climate-intervention-reports/
- https://royalsociety.org/policy/publications/2009/geoengineering-climate
- https://groups.google.com/d/msg/uml-climate-network/H5CvC_RXx2s/-hHoYsPzBpEJ
Both reports distinguish between carbon sequestration and "albedo modification" (brightening cloud cover) but the British Royal Society commission report emphasizes the fundamental need for a transition from fossil fuels to renewable energy, and contrasts relative safety of "Carbon Dioxide Removal (CDR)" with risks of "Solar Radiation Management (SRM)", but does recognize both as planetary engineering proposals and goes on to discuss the governance and control procedures necessary to begin research and development.
Key recommendations:
- Parties to the UNFCCC should make increased efforts towards mitigating and adapting to climate change, and in particular to agreeing to global emissions reductions of at least 50% on 1990 levels by 2050 and more thereafter. Nothing now known about geoengineering options gives any reason to diminish these efforts;
- Further research and development of geoengineering options should be undertaken to investigate whether low risk methods can be made available if it becomes necessary to reduce the rate of warming this century. This should include appropriate observations, the development and use of climate models, and carefully planned and executed experiments.
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