Mention global warming to economists, politicians, or Al Gore and you’ll probably trigger discussions of the pros and cons of levying carbon taxes or trading carbon credits to reduce carbon emissions.
Last August, however, a group of researchers published an update on an alternative that is perhaps less fraught with political complexity. In the journal Philosophical Transactions of the Royal Society, 25 scientists detail an experimental plan to increase the albedo, or reflection coefficient, of the skies. [See also our article “Prozac for the Planet” by Christopher Cokinos, Autumn 2010.] “The basic principle behind the idea,” writes lead author John Latham, “is to seed marine stratocumulus clouds with sea water aerosol generated at or near the ocean surface.” Translation: make clouds thicker and whiter. This large-scale geoengineering project could increase Earth’s ability to reflect sunlight, thus cooling the globe.
The article reviews decades of literature about the science and technology behind marine cloud brightening, including precipitation pattern changes and increases in sea ice thickness. One drawback is that machines needed to accomplish the task, such as the Flettner rotor ship, may cost too much. And if not done carefully, such projects could alter global rainfall patterns or trigger other unintended ecological consequences. Still, the authors argue, the potential to maintain current global temperatures is too important to ignore.
