To power life as we know it, we continue to pump greenhouse gases into the atmosphere by burning enormous amounts of fossil fuel. Now the scientific consensus is that our reliance on fossil fuel energy is contributing to global climate change, and the consequences maybe be extremely damaging, large-scale, and unevenly spread. Yet even as many nations are recognizing the need to significantly reduce carbon dioxide emissions and transform the global energy system, there is growing concern that we will not be able to muster the political courage and popular will to overcome what is arguably the greatest challenge in human history. As a result, there is a growing interest in developing a “Plan B” to mitigate the climatic effects of greenhouse gas emissions, known as geoengineering. Indeed, two new books on the topic will be released just this week: Hack the Planet: Science’s Best Hope – Or Worst Nightmare – For Averting Climate Catastrophe (excerpt from Wired Science online) by Eli Kintisch, a reporter for Science magazine, and How to Cool the Planet: Geoengineering and the Audacious Quest to Fix Earth’s Climate, by Jeff Goodell. Further, in September 2009 the Royal Society of London released a report on geoengineering science and policy issues. And even Bill Gates is investing in geoengineering research.
Geoengineering is the deliberate, large-scale manipulation of Earth’s climate to mitigate the effects of human-caused climate change. There are two main categories that have been proposed: carbon dioxide removal and solar radiation management. Carbon dioxide removal techniques include direct carbon dioxide air capture towers, i.e. machines that could use CO2 scrubbing technology to literally suck carbon dioxide out of the air, and enhancing the capability of natural systems to absorb carbon, for example by oceanic iron fertilization to promote phytoplankton blooms. On the other hand, solar radiation management techniques aim to increase the Earth’s albedo, or reflectivity. These techniques include cloud reflectivity enhancement and, perhaps most radically, stratospheric sulfur aerosols, which effectively would artificially reproduce the well-known cooling effects of volcanoes (this approach is notably advocated by Nobel prize winning atmospheric chemist Paul Crutzen in a 2006 paper).
However, the very idea of geoengineering is controversial. Many worry that geoengineering will be viewed as an easy, technological fix, which will dampen political pressure and popular will to reduce greenhouse gas emissions. There is also concern that geoengineering may inadvertently contribute to further climate catastrophe due to our limited understanding of the complex feedback mechanisms that govern global climate dynamics. Even if the science becomes understood, there is currently no legal or regulatory framework to deal with geoengineering; could it be possible for a rogue nation or wealthy individual to unilaterally geoengineering technologies for climate warfare?
So in the future, will we rely on CO2-sucking machines and artificial volcanoes to regulate the global climate? Will we all wear giant reflective white sombreros to go along with our silver jumpsuits? Given the uncertainties and moral hazards of such a “Plan B”, we should redouble our efforts to reduce greenhouse gas emissions and transform our energy systems. But perhaps it would be prudent to study geoengineering techniques, hoping that we won’t need to use them, yet understanding their potential if absolutely necessary.
- The Economist online, http://www.economist.com/science-technology/displaystory.cfm?story_id=15814427
- Stormtroopers 365 series by Stefan on flickr, http://www.flickr.com/photos/st3f4n/4166307741/in/set-72157616350171741/