资源环境科技发展态势分析平台

Harvard University researchers announced yesterday that they are seeking to move their first stratospheric test of a balloon that could one day be used in experiments to shade the Earth from the heating effects of greenhouse gases to Sweden.

Frank Keutsch, the principal investigator of the program, said the test is being moved out of the United States in part because of the coronavirus pandemic. An alternative facility in the United States couldn’t be found to host the balloon launch scheduled for early summer.

The Swedish Space Corp.’s center in Kiruna, Sweden, offered the possibility of a land-based descent, so the balloon and its propeller-driven gondola could be reused, Keutsch explained. He added that working in Sweden would help increase international collaboration, “which is important to us.”

The first test of the project, called the Stratospheric Controlled Perturbation Experiment, is meant to see how well the balloon will operate in the thinning atmosphere at a height of 12.4 miles with an equipment payload of 1,323 pounds.

If it works, then a following test would use the propellers to slowly scatter and mix a small amount of calcium carbonate, a common form of mineral dust, into the atmosphere. The idea is to use about 4 pounds of the dust to create a test “beaker,” or a cloud that’s about 0.62 mile long and 328 feet in diameter.

After that, the balloon could loiter for as long as 24 hours, using instruments to test how the particles interact with each other and if they can limit solar radiation, thus reducing the amount being reflecting back into the atmosphere to be trapped there by former emissions. The geoengineering program is meant to prevent heat from building up in the atmosphere.

Later tests would also analyze whether dispersing substances from the balloon could harm the protective ozone layer that keeps the more harmful rays of sunlight from reaching the Earth.

Keutsch, who is a professor of chemistry and chemical biology, stressed that the tests will have to be approved by an outside advisory committee established by the dean of Harvard’s School of Engineering and Applied Sciences.

David Keith, a Harvard physicist who first proposed the experiment, explained in a press release yesterday that new models showed that the aerosol would likely reduce ozone in the “beaker” by less than 3%.

Keith explained in a video released earlier this month that the point of the atmospheric test was to provide real data to make sure the models are correct. “The big question is how could we be wrong?” he added.

Such geoengineering processes might be needed on a large scale even if global leaders are able to reduce greenhouse gas emissions to net zero by 2060, Keith said.

Future generations, he noted, will have to deal with the effects of emissions from prior years that will linger in the atmosphere for decades or longer.

“The seas will still be rising, and people will still be dying from heat waves,” he said.

Reprinted from Climatewire with permission from E&E News. E&E provides daily coverage of essential energy and environmental news at www.eenews.net.