Geoengineered cooling of planet would have 'perilous effects'

Proposals to cool Earth by injecting the atmosphere with sulfate particles would deplete the ozone layer and have "perilous effects" on the planet, according to a paper to be published Friday.

As concerns grow over climate change and global warming, large-scale efforts to alter the planet's climate through geoengineering are being taken seriously by academics.

A proposal to cool the climate with sulfate particles in the atmosphere would further damage the ozone layer, a study concludes.

(Credit: NASA)

But a study performed by the National Center for Atmospheric Research (NCAR) cautioned that more research is needed before so-called geoengineering efforts are pursued.

It specifically raised the alarm over the idea of regularly sending sulfate particles into the stratosphere to reduce the Earth's temperature. It's one of the most discussed geoengineering proposals put forth by Nobel laureate Paul Crutzen and others.

"Our research indicates that trying to artificially cool off the planet could have perilous side effects," Simone Tilmes, the leader of the NCAR study, said in a statement. "While climate change is a major threat, more research is required before society attempts global geoengineering solutions."

The cooling effects of suflate particles has been observed from past volcanic eruptions. The eruption of Mount Pinatubo in the Philippines, for example, had a measurable downward effect on temperatures.

The NCAR study concluded that injecting sulfates would destroy between about a fourth and three-fourths of the ozone layer above the Arctic Ocean.

That would delay recovery of the ozone layer hole above the Arctic and thus mark a major setback for international efforts to protect the ozone layer by banning ozone-depleting chemicals. The ozone blocks harmful ultraviolet rays from coming to Earth.

Other geoengineering proposals include putting a shield above Greenland to deflect the sun's rays and stimulating large-scale plankton blooms in the ocean to sequester underwater carbon dioxide.

Academics point out the obvious challenges of these geoengineering ideas, given the complexity of the climate and the prospect of managing such global ventures among different countries.