Pollution due to carbon dioxide and other greenhouse gases which contribute hugely to global warming remains untamed, as international response to calls like the Kyoto Protocol entreating industrialized countries like the US to limit their CO2 emissions remain “grossly disappointing”, as Nobel Prize winner Paul Crutzen wrote in an article in 2006 in the journal Climatic Change. Experts estimate that global warming may increase surface temperatures by as much as 6.4 ºC (11.5 ºF) if CO2 levels continue to rise as it does now. This rise in temperature may give rise to any number of situations in the future, all of which will probably have a bad effect on humans and other life forms: greater incidence of Katrina-like storms and extreme weather, extinction of plant and animal species unable to tolerate the heat, rising sea levels that can drown coastal cities, and others. So, to counter the disastrous effects of global warming, scientists like Crutzen propose very drastic solutions.
So what are some of these proposals? Pollute the upper atmosphere with sulfur dust to reflect sunlight. Put small lenses in orbit. Float large white “islands” on oceans. Bury CO2 to the depths of the ocean by lacing the waters with iron. All these mad sci-fi fixes are lumped under the heading of “geoengineering”, a new science that promises to negate the effects of global warming really fast while struggling to find a serious audience in the scientific community.
While geoengineering received little attention until Crutzen’s paper was published, the idea of deliberately manipulating the atmosphere to suit human needs has been around in the fringes since the beginning of the 20th century. The warming effect of CO2 emissions on land temperature was explored in 1905; the undesirable effects of CO2 pollution were discussed in more detail in the 1960s, and attempts at weather modification were done much earlier by the former USSR beginning in 1932. Proposals to cool the atmosphere appeared beginning in 1964.
In recent decades, the ideas of geoengineering met with considerable and understandable resistance from the scientific community. Geoengineering was deemed too impractical, with results that were insignificant or capable of wrecking more damage to the environment or both. It was only through Crutzen’s prominence as an expert in atmospheric chemistry and the persistence of its proponents that geoengineering finally grabbed the spotlight; NASA held a workshop on geoengineering in California on November 2006, and climate scientists convened in Harvard University for a geoengineering conference earlier that same month. And renewed perceptions toward geoengineering are favorable; now, experts generally agree that if the warming gets out of hand and other measures fail, geoengineering may be a good last resort.
So how effective is geoengineering in controlling global warming? Actual small-scale experiments on several proposed methods are yet to be done, but some show promise. Most promising of the proposals is the frequent introduction of tons and tons of sulfur particles into the stratosphere to reflect sunlight back into space, proposed by Crutzen. Computer simulations of the effects of such an action show that stratospheric shading using sulfur could counteract further projected warming indefinitely.
Still scientists show no great eagerness to the idea. Scientists fear that the immediate effects of geo-engineering will lead world leaders to abandon long-range plans to clean the atmosphere of greenhouse gases. Still, scientists who had warmed up to the idea of tweaking the climate concede that geo-engineering must be considered seriously for possible future implementation, in the face of a possibly dire future climate, because at the pace with which current strategies to alleviate global warming are being done geo-engineering could very well be our planet’s only hope.
A BBC feature detailing five big geoengineering proposals through videos.