The Overshoot Commission is talking about solar geoengineering. Not everyone thinks it should

Commission members, scientists and youth advisors are concerned the body is justifying techno-fixes to the climate crisis

Solar geoengineering aims to block the sun’s warming effect by pumping aerosols into the high atmosphere. Photo: NASA


When a group of leaders set out to discuss how to reduce the risks of overshooting the 1.5C climate goal, they were asked to examine one of the most controversial technologies to cool the planet: solar geoengineering.

Their recommendations could have broad influence on how the world considers the technology. For some insiders, it’s been uncomfortable. For critics, it’s seriously problematic. The Overshoot Commission was set up last year to discuss accelerating emissions cuts, helping the world adapt to climate change, carbon dioxide removal and solar geoengineering.

The idea of blocking the sun’s warming effect by pumping aerosols into the high atmosphere – a technology known as solar radiation management (SRM) – was once of the realm of science fiction.

But as global efforts to reduce emissions fall short, solar geoengineering is attracting growing attention as a potential cheap and fast solution to relieve the world from extreme heat. However, the technology carries major uncertainties and risks, which are not well understood.

A moral hazard

SRM won’t protect the planet from rising greenhouse gases but only temporarily offset some of the warming caused by climate change – acting as a band aid rather than a cure.

Opponents argue it is a distraction from addressing the root causes of climate change and offers polluters an avenue to avoid taking climate action.

Rich world’s leaders fail to commit to Paris global financing summit

Frank Biermann is a professor of Global Sustainability Governance at Utrecht University, who opposes the technology and gave the commission a 10-minute online presentation.

He fears the group, which was initiated by geoengineering researchers, was set up “to put SRM as an option on the table” and “build its global legitimacy”.

Several young people selected to engage with the commission told Climate Home about feeling used to give legitimacy to the technology.

Some commission members are uneasy about the discussions too. Documents obtained by Climate Home News show four commissioners raised concerns about the lack of time to discuss sensitive issues before the group publishes its recommendations in September.

World Bank set to take on risk of insuring carbon credits amid market upheaval

One concerned commissioner is Frances Beinecke, former president of the Natural Resources Defense Council (NRDC). She told Climate Home she has been “extremely worried…from the get go” about the focus on SRM.

“There are a number of us that are very aware of these concerns and are focusing on making this a useful endeavour,” she said, hoping the report will prompt the world to “double down on mitigation – and fast”.

No stone unturned

Hosted by the Paris Peace Forum, the commission comprises 13 global leaders, including former presidents and ministers, and is chaired by its president Pascal Lamy.

With the world on track to breach 1.5C, at least temporarily, Lamy told Climate Home “we have to leave no stone unturned”.

Lamy said that the commission recognises that “SRM remains – and rightly so in my view – a very controversial option".

"But", he said, "it’s not because it is controversial that it should not be looked at seriously".

Confusion surrounds China’s pledged climate finance towards the Global South

Those expecting the report to support the technology “will be strongly deceived,” he added. But “if the critic[ism] is: ‘this option should never be considered’, we disagree with that.”

Ruling out solar geoengineering isn’t an option for the world’s most vulnerable nations.

Commission member Anote Tong is a former president of the sinking islands of Kiribati. He said solar geoengineering is "another attempt by humanity to control nature".

But, he added, “we are facing a catastrophe and we’re trying to survive. What other options do we have?”

Wrong priority

Margot Wallström, Sweden’s former foreign minister, disagrees. Discussing SRM is “the wrong priority,” she said. “We know what we have to do [to address climate change] so let’s focus on that”.

Originally a member of the commission, Wallström left the group after being unable to attend the first meeting, citing a lack of time to participate.

In private, Wallström felt uneasy about the focus on SRM in briefing documents and felt the discussions were edging towards “how do we take this on,” she told Climate Home.

Bitter conflicts stop Eastern Europe from choosing next year’s Cop host

After disengaging and learning more about the technology, Wallström said she felt leaving the group had been “the right thing”. “I’m totally against it. I think it’s crazy,” she said of solar geoengineering.

Others are concerned too. Youba Sokona, vice chair of the Intergovernmental Panel on Climate Change, was one of 11 members of a steering committee convened to shape what an overshoot commission would look like.

Sokona declined to join the group arguing it was “very premature” to discuss SRM and would distract attention and resources away from reducing emissions, he told Climate Home.

The origins

The commission was set up by academics involved in geoengineering research. The idea was first floated by Edward Parson, who leads the Emmett Institute’s Geoengineering Governance Project at the University of California.

Supported by the Paris Peace Forum, the Emmett Institute and Harvard University – where applied physics professor David Keith launched a major solar geoengineering research programme – began a consultation on geoengineering governance which led to the commission’s creation.

Diplomatic discussions on the issue became critical to research advocates when Keith’s group halted high-profile testing in the atmosphere above Sweden after outcry by indigenous Saami people.

Both Parson and Keith remain involved with the commission’s secretariat, which includes geoengineering researchers Joshua Horton, of Harvard’s research group, and Jesse Reynolds.

Feeling used

Several members of the youth engagement group told Climate Home they were concerned about the secretariat’s “one-sided” views. Two of eight have left the group.

“We were only there to make them seemingly more open to engage with diverse people and opinions,” said a youth who spoke to Climate Home on condition of anonymity.

Gina Cortés Valderrama, of Colombia, who left earlier this year, said young people and former politicians with no extensive knowledge of SRM were being “instrumentalised” to normalise discussing how to govern the technology in view of potential future deployment.

Creeping "techno-fixes into the political agenda…results in a very dangerous distraction from the just and equitable phase out of fossil fuels that we need,” she said.

Fake social media profiles wage “organised” propaganda campaign on Cop28

In a letter in February, the youth group accused the secretariat of “a lack serious intention to facilitate meaningful and genuine participation”.

This prompted the Children Investment Fund Foundation to pull the plug on a $500,000 grant to the commission, email correspondence shows.

The secretariat apologised for initial “suboptimal” participation. Since then, Lamy said the youths had been playing an important role and were now considered like “advisors”. The youth group presented its recommendations in person at a meeting in Nairobi in May.

‘Can’t put genie back in the bottle’

Commissioners insist their deliberations are independent from the secretariat’s views. “This will be the commissioners’ report, not the secretariat’s,” said Beinecke.

The recommendations, she said, will be “very cautious” on SRM but “somebody has to be talking about it”.

“It’s out there now, you can’t put the genie back in the bottle. You need more research, you need broader participation across the world, you need a governance mechanism,” she said, citing the risks of a repeat of a rogue experiment that took place in Mexico this year.

But for a growing group of scientists, calls for more research is cause for alarm. Writing in the New York Times, Chukwumerije Okereke, a climate and development expert from Nigeria, argued “more studies into this hypothetical solution look like steps toward development and a slippery slope to eventual deployment”.

More than 440 scientists have signed an open letter advocating for an international non-use agreement on solar geoengineering, including a ban on outdoor experiments.

Biermann, who led the initiative, said: “Some American philanthropists who have made their fortunes with technology seem to believe that quick technofixes can now also save humanity and global capitalism from the climate crisis. Yet solar geoengineering is only a false solution that would make the climate crisis even worse.”

Read more on: World | | |