Geoengineering 'can't just slam on the brakes' on rising sea levels

London, Aug 24 (ANI): Geoengineering techniques such as space mirrors or volcanic blasts won't help curb rising sea levels unless they employ extreme measures, says a new study.

The reason is that sea levels respond slowly to changes in Earth's temperature, says John Moore, a palaeo-climatologist at Beijing Normal University.

"You can't just slam on the brakes instantaneously," Nature quoted him as saying.

Moore and his team proposed the idea of space mirrors to reduce incoming sunlight, and sulphates being shot into the upper atmosphere to create a bright, sunlight-reflecting haze.

Either scheme could offset the atmospheric warming caused by carbon dioxide build-up until at least 2070 but they found that this would reduce this century's sea-level rise by only some 39 centimetres out of a projected 'no-intervention' rise of about 1 metre.

To nip sea-level rise in the bud, the scientists calculated, either injections of sulphur dioxide aerosol into the stratosphere equivalent to more than 2.5 Pinatubo eruptions every four years, or a commitment to constructing an ever-expanding space mirror would be required.

And the geoengineering must be continued or temperatures will quickly rebound to what they would have been without intervention, they said.

Richard Alley at Pennsylvania State University in Philadelphia said that it is only the beginning of trying to determine how glaciers might react to geoengineering.

"In many ways," he said, "this large advance serves to show how far we have to go before climate modelling of geoengineering is really good enough that useful regional projections could be made to guide decision-makers."

Moore concluded by saying, "Anything that isn't reducing the amount of carbon dioxide in the atmosphere is like putting [on] a bandage rather than actually solving the problem."

The study is published in Proceedings of the National Academy of Sciences. (ANI)