January 29, 2009
New Methods Could Help Mitigate Global Warming
Certain geoengineering schemes could be complementary to proposed cuts in greenhouse gas emissions aimed at fighting global climate change, researchers reported on Tuesday.
A team of researchers from Britain's University of East Anglia conducted the first study to determine the climate cooling potential of various geoengineering schemesGeoengineering involves manipulation of the environment on a large scale using methods such as fertilizing the Earth's oceans with nutrients or using giant mirrors to reflect dangerous rays.
"The realization that existing efforts to mitigate the effects of human-induced climate change are proving wholly ineffectual has fuelled a resurgence of interest in geo-engineering," said the study's lead author Professor Tim Lenton, of UEA's School of Environmental Sciences.
"This paper provides the first extensive evaluation of their relative merits in terms of their climate cooling potential and should help inform the prioritization of future research."
"We found that some geoengineering options could usefully complement mitigation, and together they could cool the climate, but geoengineering alone cannot solve the climate problem," said Lenton.
Among proposed geoengineering techniques, researchers found that injections of sulphate or other manufactured particles into the stratosphere could have the greatest potential to cool the climate back to pre-industrial temperatures by 2050, but they also carry the greatest risk of rapid warming if replenishment was suddenly stopped.
Researchers also acknowledged development of a new combined heat and power plant at UEA that will use biomass waste and new forestry plantations for energy, and combusting them in a way that captures carbon as charcoal.
Other key findings include: Increasing the reflectivity of urban areas could reduce urban heat islands but will have minimal global effect; globally ineffective schemes include ocean pipes and stimulating biologically-driven increases in cloud reflectivity; Enhancing carbon sinks could bring CO2 back to its pre-industrial level, but not before 2100 "“ and only when combined with strong mitigation of CO2 emissions.
Additionally, researchers acknowledged "the beneficial effects of some geo-engineering schemes have been exaggerated in the past and significant errors made in previous calculations."
The report it published in the journal Atmospheric Chemistry and Physics Discussions.
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