28 Jan 2009 05:01:26
Geoengineering is no climate change silver bullet
Climate engineering methods designed to provide solutions to the issue of global warming have been evaluated by a scientist who notes researchers increasingly talking about the need for a technical fix for climate change.
Tim Lenton of the University of East Anglia carried out the evaluation of possible geoengineering methods because, he told New Scientist, scientists had reached a "social tipping point" and were considering which techniques could help avoid climate change.
In his study he defined geoengineering as "large-scale engineering of our environment in order to combat or counteract the effects of changes in atmospheric chemistry".
He noted that existing geoengineering solutions to rising temperatures are based on stopping solar radiation from being absorbed by the earth or removing carbon dioxide from the atmosphere to allow heat to leave the earth.
None of the methods he studied provided a silver bullet to climate change, he said.
The most effective, but also most dangerous methods, involved stopping the suns radiation from reaching earth. In this category he studied proposals such as stratospheric mists of sulphur, and orbiting space mirrors.
Following blocking the sun, the report concluded "scrubbing" carbon dioxide - removing it from the air would be the next most effective mechanism.
He also calculated that fertilising the seas with iron to boost development of carbon absorbing plankton had attracted more attention than it deserved.
The report considered a simple solution - burying and burning vegetable waste to turn it into charcoal - thereby keeping the carbon out of the atmosphere.
This solution requires little technology and can also fertilise the soil, though its potential impact is minimal.
Last week, the German research vessel Ploarstern was called back from a mission to fertilise a patch of the Southern Ocean to allow an independent environmental impact assessment to be carried out.http://researchpages.net/media/resources/2009/01/27/acpd-...