On the second flight, In September 2022, the under-loaded balloon burst about 15 miles above Earth during a drop in atmospheric pressure, releasing about 400 grams of gas into the stratosphere. That may be the first time a measured gas load has been released into the stratosphere as part of a geoengineering effort. Both balloons were released from a launch site in Buckinghamshire in southeast England.
However, other attempts have been made to deposit sulfur dioxide in the stratosphere. Last April, the founder of a company called Make Sunsets said he tried to release it during a pair of balloon flights from Mexico, as MIT Technology Review previously reported late last year. It’s unclear whether it was successful, because the plane didn’t include equipment to determine where the balloons exploded, said Luke Eiseman, the startup’s chief executive.
The Sunset effort has been criticized by geoengineering researchers, critics of the field, and the Mexican government has announced plans to ban and halt any solar geoengineering experiments in the country. Among other issues, observers were concerned that the startups were moving forward without prior notice or approval, and that the company ultimately wanted to generate revenue by selling “cooling credits.”
Lockley’s trial was different in several ways. It was not a commercial enterprise. The balloons were equipped with instruments that could track flight paths and monitor environmental conditions. They also include several safety features designed to prevent the balloons from deflating when filled with potentially hazardous gases. The group also obtained flight permits and submitted to aviation authorities what is known as a “Notice to Airmen,” which ensures that pilots are aware of flight plans in the area.
Some observers say the amount of sulfur dioxide released during the UK project does not pose any real environmental risks. In fact, commercial flights routinely produce many times that amount.
“This is literally a harmless article or a harmless experiment,” said Gernot Wagner, a climate economist at Columbia University. Geoengineering: Gambling.
But some are still concerned that the effort is proceeding without broad public disclosure and early engagement.
Shuchi Talati, an American University-based scholar who is founding a non-profit organization focused on governance and justice issues in solar geoengineering, fears a growing indifference to the importance of research governance in this space. That refers to a set of rules and standards regarding scientific validity and control of proposed experiments, as well as public transparency and participation.