London, September 02: Sci-fi proposals to cool the planet are laden with risk but may be Earth’s only hope if politicians fail to tackle global warming, scientists said on Tuesday in their biggest evaluation to date of “geo-engineering” concepts.
The verdict by Britain’s prestigious Royal Society came little more than three months before a UN showdown in Copenhagen on how to reduce the carbon emissions that drive climate change.
John Shepherd, a professor at Britain’s University of Southampton, who chaired a 12-member panel which assessed the evidence, said geo-engineering was filling a perilous political void.
“Our research found that some geo-engineering techniques could have serious unintended and detrimental effects on many people and ecosystems – yet we are still failing to take the only action that will prevent us from having to rely on them,” he said.
The report cautiously said some geo-engineering schemes were technically feasible but were shadowed by safety worries and doubts about affordability.
Provided these questions were answered, such projects could be a useful tool as part of a worldwide switch to a low-carbon economy, it said.
‘Serious hearings’
But, the report warned, other geo-engineering schemes are so costly or so freighted with risk and unknowns that they should only be considered a last-ditch fix.
Just five years ago, geo-engineering was widely dismissed by mainstream climate scientists as quirky or delusional. As recently as 2007, the UN’s Intergovernmental Panel on Climate Change (IPCC) cautioned of its potential risk and unquantified cost.
But the schemes are now getting a serious hearing in many quarters, helped by mounting evidence that climate change is advancing faster than thought while progress towards a carbon-curbing UN treaty is moving at glacial speed.
Supporters say geo-engineering can buy time to let politicians hammer out a deal or wean the global economy off polluting fossil fuels.
The report, “Geoengineering the climate: Science, governance and uncertainty”, was based mainly on peer-reviewed literature.
It took a year to carry out, and the Royal Society came under fire from green groups who accused it of handing a cloak of respectability to a once-mocked scientific fringe.
The authors said geo-engineering fell into two main categories.
The most promising entails removal of carbon dioxide, such as by planting forests and building towers that would capture CO2 from the air.
—Agencies