Geoengineering schemes range from the low-tech, such as planting trees, to sci-fi, such as placing mirrors in orbit between Earth and the sun. All would work either by diverting solar energy away from Earth or by sucking carbon dioxide out of the atmosphere to dampen the greenhouse effect (see diagram).
Previously, the idea of tweaking the climate in this way was anathema to most scientists. Apart from the technical challenges and environmental risks, many argued that endorsing the concept might scupper international negotiations for a post-Kyoto protocol to reduce global emissions. But it’s becoming clear that moves to cut global carbon emissions are too little and too late for us avoid the worst effects of climate change. “There is a worrying sense that negotiations won’t lead anywhere or lead to enough,” says Lenton. “We can’t change the world that fast,” says Peter Liss, who is scientific adviser to the UK parliamentary committee investigating geoengineering. Extraordinary measures may now be the only way of saving vulnerable ecosystems such as Arctic sea ice.
Source: New Scientist.