Geoengineering: A Proposal for Mitigating Climate Change

Michele Perch

I chose to discuss “tech fix” solutions to climate change with the class because I have examined global warming from an economic perspective, but not through a scientific or technological lens.  I was particularly interested in geoengineering because it changes the way we look at solutions to climate change.  Instead of preventing further warming by changing our behaviors or using economic models to discourage emissions, some types of geoengineering may actually eliminate the damage we have already done, like sunshade technologies.  Other forms of geoengineering, like carbon capture techniques, simply reduce additional emissions.  I chose to include them, however, to show that geoengineering is not so farfetched.  We already have the capacity to use technology that allows us to continue with our current behaviors while mitigating further climate change at the same time. 

Sunshade technologies are intended to reflect the sun’s rays away from the Earth and induce a small reduction in the atmosphere’s temperature.  Sunshade technologies range from distributing sulfur particles high into the atmosphere to launching large mirrors into the upper atmosphere.  Other techniques that have been discussed include placing fake ice caps in the ocean, spraying clouds with salt water to make them whiter, and making rooftops pale or white.  With the exception of launching large mirrors into space, implementing these technologies is neither difficult nor expensive.

There are several potential consequences to sunshade technologies, however.  The depletion of the ozone layer, ocean acidification, and changes in rainfall patterns may occur, which would affect human health and marine ecosystems.  For instance, reductions in the frequency and intensity of monsoons may greatly affect the crops in Asian countries. This would diminish the economic well-being of farmers, and it could significantly diminish the food supply for these countries, and countries around the world that import their goods.  The only way of measuring the effects of sunshade technologies are through computer models or natural experiments.  One such incident occurred in 1991 when Mount Pinatubo in the Philippines erupted, sending sulfur particles into the stratosphere, and reducing temperatures in the northern hemisphere by about 1 degree Fahrenheit. 

Carbon capture technologies, on the other hand, are less risky.  They would be used to sequester carbon from the air, either by filtering the carbon dioxide directly from industrial plants or from the open air.  Tubes would carry the carbon deep into the ground and store it in areas with porous rock and a hard top layer that contains the carbon.  Carbon dioxide could be stored deep under the sea as well.  Iron filings can also be dumped into the ocean to enhance plankton, which absorbs a lot of carbon dioxide.  Carbon capture and storage is a bit more expensive than most sunshade technologies, but it is supported by environmental nonprofits as a safe and effective technique to prevent further climate change.  It is also less risky because it simply alleviates further global warming, rather than trying to eliminate the damage we have already done.

Another technique that alters the climate’s behavior and has already been widely used is cloud seeding.  Cloud seeding involves shooting silver iodide into the clouds to induce the fall of precipitation.  The technique has been studied in the United States, but not extensively.  On the other hand, China has invested heavily in cloud seeding research and technology because of severe droughts.  China’s population is also more open to using it.  Silver iodide does not dissolve in water, so there are a few minor concerns regarding that safety of drinking water.  However, overall, seeding the clouds – and thus altering the atmosphere and the climate – is not as controversial in China as one might think.  Cloud seeding may be paving the way for geoengineering.  It is a man-made technology that directly alters the climate, and it is successful and widely accepted in many cases. 

In class, we focused specifically on the more controversial sunshading technologies.  Since sunshade technologies have risky environmental effects and fairly serious moral implications, the class generally agreed that they would not be used on a wide scale unless one or more nations were faced with a “lifeboat” situation in which survival was not possible without a last resort effort to remove the effects of climate change.  Any country in imminent danger could feasibly use sunshade technology.  However, this would have externalities on the entire world.  We have already seen that China is not afraid to alter its climate through cloud seeding.  Will China or other nations take this same initiative when it comes to using more controversial cooling technologies?

The class came to the consensus that the scariest aspect of geoengineering was that any country could easily use sunshade technology.  Very little sulfur is actually needed to induce significant cooling in the Earth’s temperatures, and it is fairly inexpensive.  Particles would only need to be released once every one or two years, as sulfur has a long life expectancy.  Additionally, the concept of national sovereignty makes this more difficult to prohibit.  In other words, every nation has the right to take action against climate change, no matter in what form.  There are no international guidelines concerning the types of technology that can be used, just as there is no international law that prohibits nations from using other policy mechanisms that mitigate climate change.  The class agreed that negotiations on a global scale are often very difficult to reach, and a United Nations-style meeting that would discuss rights to the atmosphere does not seem likely in the near future. 

We also discussed geoengineering in relation to exhibiting political power.  Perhaps the first country to use geoengineering will be comparable to the first country to reach the moon in the space race of the 1960’s.  On the other hand, perhaps the first nations to use geoengineering will be impoverished countries, which suffer disproportionately from climate change.  Thus, it would not seem likely that a small island nation or developing country would be considered a great power simply because it used sunshade technologies to save its own country.  This is also different from the space race in that it does not take extraordinary technical or financial capabilities to implement certain types of geoengineering, including sunshading.

Phasing-in geoengineering techniques might be advisable, so that scientists could test their effects on the climate.  At the same time, a blend of other policy mechanisms could still be considered or implemented, such as a cap-and-trade program, a carbon tax, or even another less risky form of geoengineering, such as carbon capture and storage.  This would give us a better idea of how well sunshading would hold up, and its potential side effects.  Since geoengineering cannot be tested like many other forms of science (i.e. we test the effects of drugs on rats) this is the best way besides computer models to examine the effectiveness of sunshade technology.  Additionally, it would give the public time to adapt to the idea of geoengineering.  Conversely, it could give the public enough time to develop a large opposition movement against sunshading or other risky or expensive forms of geoengineering. 

Ultimately, humans are not programmed to be worried about climate change.  We are wired to react to imminent threats, and perhaps we have not addressed climate change seriously enough because of this.  Thus, as a society, we have developed “quick fixes” to take care of our problems.  We want the best of both worlds – we want a healthy environment that can sustain the human population and we do not want to change our behaviors to help mitigate climate change.  Will we eventually have to utilize geoengineering technologies?  Certainly if climate change continues as projected and we cannot implement sufficient policies or changes in behavior, it becomes much more probable.


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last updated 5/14/10