A controversial experiment to artificially cool the Earth was canceled – what we know about why

After years of legwork, Harvard researchers canceled plans to test a controversial theory for cooling the planet by sending sunlight-reflecting particles into the atmosphere. Now, members of an independent advisory committee tasked with addressing ethics and safety issues are sharing what they learned from the ill-fated project.

ONE political analysis published in the magazine Science on Friday highlights how important it is to talk to people on the ground before launching an experiment, especially one linked to potentially planet-altering consequences. The article echoes recent calls to obtain policies in place to protect against any unintended side effects.

Until very recently, the idea of ​​reflecting sunlight back into space to combat global warming – a process called solar geoengineering – seemed to be firmly rooted in science fiction. But with the worsening of the climate crisis, the idea began to leave the margins of academic research to spark a more serious debate.

Some researchers and their Silicon Valley supporters want to test the theory. And time is running out to establish rules for how to design these experiments responsibly, which could help determine whether solar geoengineering will cause more harm than good.

“One of the main messages that comes out of this is that public involvement is necessary even when you don’t think that the impact of the experience will be felt in a real way, in a concrete way, in real time. This question has a very long tail and a much deeper meaning for many people,” says Sikina Jinnah, lead author of the Science policy analyst and professor of environmental studies at the University of California, Santa Cruz.

Harvard researchers launched the project called SCoPEx – short for Stratospheric Controlled Perturbation Experiment – ​​in 2017. To better understand any potential risks or benefits associated with solar geoengineering, it planned to conduct the first outdoor experiment using reflective particles. He would have released some of these aerosols into the stratosphere via a balloon and then piloted the balloon back through the plume to take measurements. The goal was to observe how particles interact with each other and with other elements in that environment — resulting in data that could be used to make more accurate computational models.

That never happened. There was supposed to be an engineering test flight without any particle release in Sweden in 2021, but it was dismantled after facing strong opposition of local indigenous leaders. A major point of contention was that researchers initially did not achieve the Sami Councilrepresenting the organizations of the indigenous Saami peoples of the region. Members of the SCoPEx advisory committee could not agree whether to consult Saami, as the test flight would not release anything into the atmosphere, according to the political analysis. The majority ultimately ruled that the test flight could proceed if there were no significant environmental concerns to flag.

THE Sami Council anyway, he found out about the plans and wrote a strong text letter to the advisory committee demanding that the researchers cancel the flight. They said it was “remarkable” that the test flight took place without consulting the Saami people or other local stakeholders, given the controversies swirling around solar geoengineering. Local environmental advocates, including Swedish chapters of Greenpeace and Friends of the Earth, also signed the letter.

Solar geoengineering is still considered a “false solution” to climate change by many activists. Injecting particles into the atmosphere attempts to recreate the way erupting volcanoes can temporarily legal the planet for releasing sulfur dioxide. But sulfur dioxide can also cause acid rain, worsen the hole in the Antarctic ozone layer or have other unforeseen consequences. There are also fears that solar geoengineering could undermine clean energy transition efforts, or lead to a dangerous swing in global temperatures, if it is ever implemented and then abruptly stopped.

“We noticed that [solar geoengineering using reflective particles] it is a technology that carries risks of catastrophic consequences… Therefore, there are no acceptable reasons to allow the SCoPEx project to be conducted in Sweden or elsewhere,” the letter from the Saami Council says.

The advisory committee ultimately recommended canceling the test flight in Sweden after receiving the letter. In 2023, Harvard told the advisory committee that it had “suspended”the project and then canceled completely in March this year. The project “struggled with both intense media attention and how to respond to calls from the scientific advisory committee to engage broadly and formally with the public,” Nature reported at the time, citing one of its project leaders.

“I am grateful for the insights from the SCoPEx Advisory Committee. Their careful analysis is valuable to the scientific community as it considers important governance issues,” said Frank Keutsch, who was the SCoPEx principal investigator. The edge in an email. He did not elaborate further on the reason for the end of the project.

More than an ad hoc committee will be needed to effectively oversee the advancement of geoengineering research, according to the recently published policy analysis. “The time has come for governments to start discussing the coordination of research governance”, he states.

These talks have already begun at the European Commission and the United Nations Environment Assembly, although they have not yet led to any new concrete policies. There was a moratorium on large-scale geoengineering since the 2010 United Nations conference on biodiversity, but excludes small-scale scientific investigation.

And small, impromptu initiatives have become a bigger concern lately. Last year, the founders of a geoengineering startup grilled fungicide in a California parking lot to produce sulfur dioxide gas that they attempted to release into the atmosphere through weather balloons. This followed a similar balloon launch in Mexico, which motivated the government there to stop solar geoengineering experiments. The political analysis calls the startup’s efforts “irresponsible” and “not linked to any legitimate scientific pursuit.”

Since then, there have been calls to establish rules on how to regulate future experiments or to stop solar geoengineering altogether. But without broader policies in place, keeping up with new geoengineering efforts can be a bit like playing whack-a-mole around the world.

Such policies could also ensure that nearby communities have a say in projects that may affect them. And as we learned from SCoPEx, even more scholarly efforts can skip this step to their own detriment.