The story appears on

Page A6

December 3, 2011

GET this page in PDF

Free for subscribers

View shopping cart

Related News

Home » World

Intervention considered to help cool down Earth

BRIGHTEN clouds with sea water? Spray aerosols high in the stratosphere? Paint roofs white and plant light-colored crops? How about positioning "sun shades" over the Earth?

At a time of deep concern over global warming, a group of scientists, philosophers and legal scholars examined whether human intervention could artificially cool the Earth - and what would happen if it did.

A report released late Thursday in London and discussed yesterday at the UN climate conference in South Africa said that - in theory - reflecting a small amount of sunlight back into space before it strike's the Earth's surface would have an immediate and dramatic effect.

Within a few years, global temperatures would return to levels of 250 years ago, before the industrial revolution began dumping carbon dioxide into the air, trapping heat and causing temperatures to rise.

But no one knows what the side effects would be. They could be physical - unintentionally changing weather patterns and rainfall. Even more difficult, it could be political - spurring conflict among nations unable to agree on how such geoengineering, will be controlled.

The idea of solar radiation management "has the potential to be either very useful or very harmful," said the study led by Britain's Royal Society, the Washington-based Environmental Defense Fund and TWAS, the academy of sciences for the developing world based in Trieste, Italy.

The report grew out of three days of talks in a country retreat last March, the climax of a year-long dialogue spanning experts in 22 countries.

It was prompted in part by the failure of a 20-year UN negotiating process to take decisive action to curb greenhouse gas emissions, mainly from burning fossil fuels, responsible for climate change.

"The slow progress of international climate negotiations has led to increased concerns that sufficient cuts in greenhouse gas emissions may not be achieved in time to avoid unacceptable levels of climate change," the report said.

But geoengineering is not an alternative to climate action, said John Shepherd, a British oceanographer from the University of Southampton, a lead author of the report.

"Nobody thought this provides a justification for not reducing carbon emissions," Shepherd said. "We have to stick with Plan A for the time being," he said. "This would buy time to make the transition to a low-carbon economy."

The Intergovernmental Panel on Climate Change foresees temperatures rising 6.4 degrees Celsius by 2100, swelling the seas with melted glacial water and disrupting climate conditions around the globe. Shepherd said report was intended to start conversation.

"I hope it can be continued in a formal framework, as eventually somebody will have to take some decisions."



 

Copyright © 1999- Shanghai Daily. All rights reserved.Preferably viewed with Internet Explorer 8 or newer browsers.

沪公网安备 31010602000204号

Email this to your friend