Marine Log - November 2007 - (Page 4) Nick Blenkey Senior Editorial Consultant Second Thoughts Good news about global warming n Op Ed piece in the New York Times of Oct. 24, 2007 needs to be given serious attention. Written by Ken Caldeira, a scientist at the Carnegie Institution’s Department of Global Economy, it’s entitled “How to Cool the Globe.” What’s attractive about Dr. Caldeira’s proposal is that it suggests something we can do to combat global warming. That’s a big change from the usual prescriptions, which are generally about not doing things. So, what does Dr. Caldeira suggest? “One idea is to counteract warming by tossing small particles into the stratophere (above where jets fly). This strategy may sound far fetched, but it has the potential to cool the earth within months.” When Mount Pinatubo, a volcano in the Philippines erupted in 1991, he notes, it resulted in sulfate particles in the atmosphere that reflected the sun’s rays back to space and, as a consequence, the earth briefly cooled. “If we could pour a five gallon bucket’s worth of sulfate particles per second into the stratosphere, it might be enough to keep the earth from warming for 50 years,” writes Dr. Caldeira. What’s interesting is that his proposal is obviously not a particularly new one, because he cites a 1992 National Academy of Sciences report that suggest naval artillery, rockets and aircraft exhaust as a means of putting the particles up there. Maybe we should bring the battleships out of retirement. The Iowa is, for example, in the Suisun Bay Reserve Fleet, Benecia, Calif. and available for A donation as a museum ship. Maybe reengineering its giant guns to launch Dr. Caldeira’s sulfate particles would be a better use. At this point, it’s worth emphasizing that Dr. Caldeira is hardly a scientific lightweight, his idea is not nutty—and, alas, he’s not suggesting it as a total solution to global warming. He says that “ninety-nine percent of the $3 billion federal Climate Change Technology Program should still go towards developing climate friendly energy systems. But one percent of that money could go toward working out geoengineered climate fixes like sulfate particles in the stratosphere, and developing the understanding we need to ensure that they wouldn’t just make matters worse.” Not making matters worse is something that’s particularly relevant to the issue of limiting emissions from ships. This is a hot-button issue, particularly in Europe. Ships are fast becoming the biggest source of air pollution in the EU. According to the European Commission, unless more action is taken they are set to emit more than all land sources combined by 2020. Helping raise the profile of ship emissions are “ship trails” or “ship tracks.” These are of shallow stratus clouds that trail behind ships and are wide enough to be seen in visible satellite imagery. They appear to be caused by particulate in ships’ emissions precipitating water emissions. Guess what? According to some scientists, they tend to cool the global climate, albeit for a short time. Don’t stand up and cheer just yet. SOx emissions are not particulate emissions. SOx emissions from ships (or anything else) are classified as a pollutant because they react with water vapor to form sulfuric acid mist. The acid is extremely corrosive and harmful to the environment. I think everyone remebers the days of acid rain. In shoreside power station emissions, about 95% of the sulfur in the fuel will be emitted as SO2, from 1 to 5% to as SO3, and 1 to 3% as sulfate particulate. Sulfate particulate is not considered part of the total SOx emissions. However, all particulate matter is a health concern, especially particles under 10 microns size. For sulfur emissions from ships to be considered in any way beneficial, it seems they would have to be SOx-free and limited to particulate above 10 microns diameter. So, using battleship guns to shoot sulfur particulate into the atmosphere might be a good idea (if the particles are above 10 microns diameter). Just letting ships burn whatever fuel is cheapest and emit unlimited amounts of SOx and particulates is not. Right now IMO has convened a Group of Experts to evaluate various proposals for limiting sulfur and other emissions from ships. Its task could be trickier than it seems. nblenkey@sbpub.com 4 MARINE LOG NOVEMBER 2007 www.marinelog.com http://www.ebdg.com http://www.ebdg.com http://www.marinelog.com
For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.