EarthTalk: Scientists study ways to pull greenhouse gases out of our atmosphere, but the idea is controversial.
A: While most of the world fixates on how to reduce the amount of carbon dioxide (CO2) and other greenhouse gases we emit into the atmosphere, scientists and engineers worldwide are working on various geoengineering technologies – many of which are highly theoretical – to mitigate global warming and its effects. Many scientists oppose using new technology to fix problems created by old technology, but others view it as a quick and relatively inexpensive way to help solve our most vexing environmental problem.
One theory for reducing global warming involves deflecting heat away from the Earth’s surface using satellites with movable reflectors or injecting sunlight-deflecting particles high in the atmosphere. Computer models suggest that blocking 8 percent of the sun’s earthbound radiation would effectively counteract the warming effect of our CO2 pollution.
The idea was inspired by the cooling effects of large volcanic eruptions – such as Mt. Pinatubo in the Philippines in 1991 – that blasted sulfate particles into the stratosphere. These particles reflect part of the sun’s radiation back into space, reducing the amount of heat that reaches the atmosphere.
Another technological fix involves sequestration, the storing of CO2 deep underground or deep in the ocean. Some of the nation’s largest utilities, which are also “washing” coal to filter out impurities, are working on ways to capture the CO2 their power plants emit and store it deep underground. The cost of such technology is prohibitive now, but new regulations could soon make it more feasible.