Desist from geoengineering to prevent melting of Antarctic ice sheet: Scientists

Technical methods artificially influencing the climate have been discussed for some time under geoengineering.

Artificially 'dimming the sun' alone will not prevent Antarctic ice sheets from melting, scientists say.

The artificial influence, which is laden with high risks and unforeseeable side effects, could prove to be an 'effective tool' to slow or even prevent West Antarctic ice sheet collapse if deployed by mid-century 'in a medium emissions scenario', the scientists at the University of Bern, Switzerland, estimated using modelling simulations.

The study also found that under unabated emissions and a mid-century deployment of the artificial technique, the ice sheet collapse could be delayed somewhat, but not prevented.

The most effective way to prevent long-term collapse of the ice sheet, however, was rapid decarbonisation, the authors emphasised in their study published in the journal Nature Climate Change.

The chances of a longer-term stable ice sheet were the greatest if greenhouse gas emissions were reduced to net zero 'without delay', they said.

Technical methods artificially influencing the climate have been discussed for some time under the term geoengineering.

However, the majority of climate researchers have been critical of them: high risks, incalculable consequences for future generations, they have said.

"The window of opportunity to limit the global temperature increase to below 2 degrees is closing fast," said lead researcher and ice modelling specialist Johannes Sutter.

"So, it is possible that technical measures to influence the climate will be seriously considered in the future. Therefore, it is necessary to use theoretical models to study the effects and risks of solar radiation management (SRM)," he said.

SRM is a term used to describe various methods of blocking solar radiation in order to make the Earth cooler.

Avoiding tipping points is a key attraction of geoengineering. At these points, which include the melting of the West Antarctic and Greenland ice sheets and the associated metre-high sea level rise, climate could change abruptly and irreversibly.

"Observations of ice flows in West Antarctica indicate that we are very close to a so-called tipping point or have already passed it," explained Sutter.

"With our study, we therefore wanted to find out whether a collapse of the ice sheet could theoretically be prevented with SRM."

Sutter and team investigated the effects of introducing aerosols, which are suspended particles in a gas, into the stratosphere (one of the atmopheric layers) to blocking solar radiation from the earth - a dimming of sun.

Using ice model simulations, the study examined the possible development of the ice sheet under different future greenhouse gas scenarios.

Rapid decarbonisation and reducing greenhouse gas emissions to net zero without delay still remain our best bet to save the ice sheets from collapsing, the study authors maintained.