Reforestation and other carbon sink enhancements such as bio-char, were found to be more effective than ocean fertilization in the short term. Photo: Matthew McDermott
Geoengineering projects to combat global climate change seem to bring out vocal opinions, both pro and con, and while their are compelling arguments from both sides, one thing that I think can be agreed upon is that more research is needed into the benefits of such schemes, as well as possible side effects and unintended consequences. Well, here it is.
A new research paper published in Atmospheric Chemistry and Physics Discussions claims that it is the first comprehensive assessment of the climate cooling potential of different geoengineering schemes. Carried out by researchers at the University of East Anglia, key findings of the paper include:Enhancing Carbon Sinks + Strong Emissions Reductions
By 2100, enhancing natural carbon sinks (though large scale afforestation, bio-char production, etc.) could be effective in bringing CO2 levels back to pre-industrial levels if combined with strong reductions in CO2 emissions.
Stratospheric Aerosol Injections & Sunshades in Space
Though they carry the greatest risk of unintended consequences, stratospheric injections of aerosols have the greatest potential to cool the climate by 2050. One potential risk is that these sort of injections would have to be continually replenished, and if stopped suddenly, rapid warming would ensue.
Ocean Iron Fertilization
Ocean fertilization options are "only worthwhile if sustained on a millennial timescale and phosphorus addition probably has greater long-term potential" than either iron or nitrogen.
New Forests & Bio-Char Better Than Ocean Fertilization
Sequestering carbon in new forests and through adding charcoal back into the soil in the form of bio-char has greater short-term cooling potential than ocean fertilization. Bio-char was also cited as being a 'win-win for soil fertility as well as the climate."
Increasing Urban Reflectivity
While it may reduce your cooling bills and reduce the heat island effect, efforts to increase the reflectivity of buildings in urban areas will have minimal global effect.
Ocean Pipes, Increasing Cloud Reflectivity
Plans to stimulate biologically-driven increases in cloud reflectivity, and ocean pipes were deemed to be ineffective geoengineering solutions.
Those of you who want to delve into the details (probably just for the scientists among you...), here's the original paper: Radiative forcing potential of climate geoengineering
More: University of East Anglia (press release)
Geoengineering Risk Potential Not An Excuse for Inaction, Scientist Says
Ocean Iron Fertilization Test in South Atlantic Given Go Ahead
Think Ocean Geoengineering is a Good Idea? Think Again, Australian Scientists Urge