Sep 21, 2013 - 12:00:23 PM
While solar geo-engineering can't do anything about the carbon dioxide already in our atmosphere that will be causing more warming for decades to come or longer, it can help reduce the planet's carbon load moving forward, and is thus generally viewed as part of the climate solution but not the whole enchilada. That is, no matter what it is still in our best interest to reduce our carbon footprint as much as possible regardless of the whiz bang technologies scientists are developing to help.
The most practical of the solar geo-engineering techniques involves sending a specially modified fleet of jets around the globe spraying sulfates into the atmosphere that would combine with pre-existing water vapor to form aerosols. When dispersed by the wind, these sulfates would cover the globe with a haze that could reflect an estimated one percent of solar radiation back out into space. The model for such a scenario occurred naturally in 1991 when the eruption of Mt. Pinatubo in the Philippines sent some 10 million metric tons of sulfur into the atmosphere and caused a reduction in global temperatures by about one degree Fahrenheit for more than a year.
While employing such techniques might seem like a no-brainer, there are inherent risks. Alan Robock, an atmospheric scientist at Rutgers University, warns that adding sulfur to the skies, for instance, could shift rainfall patterns and hasten the thinning of the ozone layer. "We are going to put the entire fate of the only planet we know that can sustain life on this one technical intervention that may go wrong?" he asks. Another issue is the so-called "abrupt cessation" risk whereby shutting off whatever solar geo-engineering techniques are in effect could cause a sudden rise in global temperatures to previously unforeseen levels.
Given reticence about applying quick technological fixes for our climate problem, proponents of solar geo-engineering are calling for the federal government and other concerned parties to fund more research. "The balance of evidence so far suggests that solar geo-engineering could reduce climate risks, but early science might be wrong," he says. "We need experiments, which might show that it does not work."
But perhaps the biggest hurdle to implementation of solar geo-engineering is getting the nations of the world to agree on the need for it. "With solar geoengineering, at some level you've got just one knob," says Harvard energy and climate researcher David Keith, a big proponent of solar geo-engineering. "That demands collective global decision-making."
CONTACTS: Alan Robock, www.envsci.rutgers.edu/~robock
EarthTalk® is written and edited by Roddy Scheer and Doug Moss and is a registered trademark of E - The Environmental Magazine (www.emagazine.com). Send questions to: email@example.com.Subscribe: www.emagazine.com/subscribe. Free Trial Issue: www.emagazine.com/trial.
For advertising and promotion on HealthNewsDigest.com, call Mike McCurdy: 877-634-9180 or tvmike13@HealthNewsDigest.com. We have over 7,000 journalists as subscribers.