 Gregory Benford thinks Al Gore's a good guy and all, but he also thinks the star of "An Inconvenient Truth" is a little delusional. Driving a hybrid car, switching your bulbs to compact fluorescents and springing for recycled paper products are all well-meaning strategies in the fight against global warming.
But as UC-Irvine physicist Benford sees it, there's a catch. Those
do-gooder actions are not going to be effective enough to turn the
temperature tide, and even incremental political changes like reducing
greenhouse gas emissions and mining alternative fuel sources are not
forward-thinking enough. "I never believed we were going to be able to
thwart global warming through carbon restriction," Benford says.
"Carbon restriction requires nations to subvert short- and midterm
goals for a long-term goal they've read about online, and that's just
not going to work."
As an alternative, Benford has cooked up a plan that amounts to a
manmade Mount Pinatubo eruption. He has proposed shooting trillions of
tiny particles of earth into the stratosphere, where they will remain
suspended to help blot out incoming solar rays. Dirt is cheap,
chemically unreactive and easily crushable, he argues, making it a
simple matter to test this strategy on a small scale over the Arctic
before total global deployment. This plan might seem a little too
sci-fi to take seriously -- fittingly, Benford moonlights as a
Nebula-winning novelist -- but he's far from the only scientist to
lobby for a so-called geoengineering fix.
Researchers all over the world have begun advocating large-scale
climate control strategies that sound like something "The Simpsons'"
Mr. Burns might endorse, including erecting sun-blocking mirrors in
deep space, spraying tiny droplets of sulfur or ocean water into the
atmosphere to deflect sunbeams, and seeding the oceans with iron to
spur the growth of CO2-sucking phytoplankton. When a panel
of scientists addressed the ethical implications of geoengineering at
the annual American Association for the Advancement of Science
conference in February in Boston, it was a clear sign of how far this
seemingly out-there field has advanced toward legitimacy.
While no proposed geoengineering fixes have yet been tested on a
global scale, all of them have the irresistible lure of immediacy. Once
deposited, CO2 can linger in the atmosphere for more than
100 years, meaning it will take decades or centuries for
emissions-reduction policies to cool the planet significantly.
Geoengineering, on the other hand, could potentially send global
temperatures back to preindustrial levels within only a few years,
bringing the Arctic melt to a screeching halt and keeping extreme
weather patterns and rising sea levels associated with warming in
check. "Every simulation that's been done shows that geoengineering
doesn't bring the climate back perfectly," says Ken Caldeira, an
ecologist at Stanford University, "but you could put sulfur in the
stratosphere right away and it would be colder next year." Read rest...
|
