Geoengineering with fake volcanoes

Altering the climate intentionally to offset changes. [Link]

By physically altering the planet on a global scale, geoengineering projects would theoretically offset warming caused by the build-up of carbon dioxide in the atmosphere. The concept was dismissed as fringe science when it was first introduced in the 1960s. Now, what once seemed like science fiction is not only being deemed feasible, but necessary, said experts at a panel convened here Tuesday by the American Enterprise Institute for Public Policy Research, a conservative think tank.

One popular geoengineering scenario is to create an artificial volcano. Thomas Wigley, an expert on climate change based at the National Center for Atmospheric Research in Boulder, Colo., has created computer simulations that replicate the 1991 "Mount Pinatubo effect"—a temporary cooling period created by the launch of 20 million tons of sulfur dioxide into the stratosphere.

Wigley proposes mimicking the natural process by injecting sulfur dioxide or hydrogen sulfide into the same region, 60,000 to 70,000 ft. above the earth's surface. The compound would react to form a cloud of sulfuric acid droplets that would in turn reflect sunlight and cool the globe. Exactly how the material would be delivered isn't clear—cannons, balloons and high-flying military planes are some "highly speculative" options, he says.

Such a scheme isn't cheap. Depending on the frequency, delivery system and whom you talk to, estimates vary wildly from $1 billion to $50 billion a year. Whether it's worth the high price tag is still hotly debated.

Geoengineering would buy time for societies as they work on the technological revolution necessary to reduce carbon dioxide emissions, says Scott Barrett, an economist specializing in environment and international political economy at the School of Advanced International Studies at Johns Hopkins University in Baltimore.

"That's an excuse to conduct business as usual," says Alan Robock, a meteorologist at Rutgers University in New Brunswick, N.J. "It takes political will to lower carbon dioxide emissions. There are plenty of solutions already available."