During the second flight, in September 2022, the smaller payload balloon burst about 15 miles above Earth as it expanded amid reduced atmospheric pressure, releasing about 400 grams of gas into the stratosphere. This may be the first time a measured payload of gas has been verifiably released into the stratosphere as part of a geoengineering effort. Both balloons were launched from a launch site in Buckinghamshire in south-east England.
There were, however, other attempts to place sulfur dioxide in the stratosphere. Last April, the co-founder of a company called Make Sunsets says he tried to launch it during a pair of rudimentary balloon flights from Mexico, as MIT Technology Review reported late last year. It’s also unclear whether it succeeded because the plane didn’t include equipment that could confirm where the balloons burst, said Luke Eisman, the startup’s chief executive.
Make Sunsets’ efforts have been widely condemned by geoengineering researchers, critics in the field, and the Mexican government, which has announced plans to ban or even halt any geoengineering experiments in the country. Among other issues, observers were concerned that the launches occurred without prior notice or approval, and that the company ultimately seeks to monetize such launches by selling “cooling credits.”
Lockley’s experiment was different in several ways. It was not a commercial enterprise. Balloons were equipped with devices that could track flight paths and monitor environmental conditions. They also included a number of safety features designed to prevent balloons filled with potentially hazardous gases from landing. In addition, the group obtained flight permits and sent aviation authorities a so-called “notification to pilots” to ensure that aircraft pilots are aware of flight plans in the area.
Some observers have said that the amount of sulfur dioxide released during the project in the UK poses no real danger to the environment. Indeed, commercial flights usually produce many times that.
“It’s a harmless record or a harmless experiment, in the truest sense,” says Gernot Wagner, a climate economist at Columbia University and author Geoengineering: Gambling.
But some remain concerned that the effort has gone ahead without extensive disclosure and prior engagement.
Shuchi Talati, a researcher at American University who is creating a nonprofit organization focused on governance and equity issues in solar geoengineering, fears that the importance of research governance is increasingly being neglected in this space. It refers to a set of norms and standards regarding the scientific merit and oversight of proposed experiments, as well as public transparency and participation.