An early experiment toward using sun-dimming technology to cool global warming has opponents fearing a slippery slope toward engineering the climate.
Harvard University scientists plan to fly a test balloon above Sweden next year to help advance research into dimming sunlight to cool the Earth, alarming environmentalists opposed to solar geoengineering.
Open-air research into spraying tiny, sun-reflecting particles into the stratosphere, to offset global warming, has been stalled for years by controversies – including that it could discourage needed cuts in greenhouse gas emissions.
In a small step, the Swedish Space Corporation agreed this week to help Harvard researchers launch a balloon near the Arctic town of Kiruna next June. It would carry a gondola with 600 kg of scientific equipment 20 km (12 miles) high.
“There are very many real concerns” about the risks of climate change and solar geoengineering, said David Keith, who is involved in the project and is a professor of applied physics at the Harvard School of Engineering and Applied Sciences.
“Understanding them requires a range of activities including experiments,” said Keith, who is also a professor of public policy at the Harvard Kennedy School.
The unmanned flight had originally been planned for the United States but was moved, partly because of U.S. restrictions caused by coronavirus.
The flight, which requires approval from a Harvard project advisory committee, will test how to manoeuvre the balloon and check communications equipment and other systems. It would not release any particles into the stratosphere.
Still, if successful, it could be a step towards an experiment, perhaps in the autumn of 2021 or spring of 2022, to release a tiny amount – up to 2 kg – of non-toxic calcium carbonate dust into the atmosphere, Keith said.
Studying that material’s effects on high-altitude sunlight could help advance understand of how solar geoengineering might work.
A SLIPPERY SLOPE?
But opponents see the Swedish balloon as a step on a slippery slope towards engineering the climate with an artificial sunshade – something with potentially large and hard-to-predict risks, such as shifts in global rain patterns.
“There is no merit in this test except to enable the next step. You can’t test the trigger of a bomb and say ‘This can’t possibly do any harm’,” said Niclas Hällström, director of the Swedish green think-tank WhatNext?
“Swedish society is increasingly calling for real, immediate solutions to climate change,” he said – such as a rapid transformation away from fossil fuels and toward a zero-carbon society.
He said the Harvard project “represents the polar opposite”, as it could create the impression that continuing use of fossil fuels is possible.