Should we talk about solar geoengineering?

Climate altering technologies, such as using high-altitude planes to spray light-deflecting sulphur particles into the atmosphere, are among some of the options being discussed to help minimise global warming. (Credit: Paul Brennan/Pixabay)

Hailed by some as a “silver bullet” and admonished by others as a “can of worms”, solar radiation modification is stirring up debate in academic circles as they grapple with snail-paced climate action.

As the world fails to rapidly curb its greenhouse gas emissions and moves dangerously closer to warming over the 1.5ºC limit, using technology to intervene in the Earth’s natural systems and counter climate change is gaining traction – but not without controversy.

One of the most talked about geoengineering solutions, solar radiation modification (SRM), sparked heated discussions at the Geneva Science and Diplomacy Anticipator (Gesda)’s summit, held last week in Geneva.

“We have to review a number of options that had not been seriously considered or considered seriously enough, such as adaptation, carbon removal, or SRM,” Pascal Lamy, chair of the Paris Peace Forum’s Climate Overshoot Commission, said at an event on solar geoengineering.

He is heading a group of experts tasked with exploring different ways of staving off climate impacts in the case of overshooting the 1.5ºC warming limit, including new technologies, and is preparing a set of recommendations for next year on how governments but also private actors should proceed.

What is solar radiation modification?

SRM essentially entails reflecting sunlight back into space to avoid its warming effect and, according to Gesda’s projections into the future, has promising potential to become part of the toolbox to offset temperature rise within the next 25 years.

While the term makes it sound like something picked out of a sci-fi novel, SRM encompasses different techniques, some more rudimentary than others, from painting rooftops in white to spraying seawater into the air to brighten clouds. There are other even more wacky ideas that are too technically complex and costly to develop; for example, some experts have suggested deploying a parasol the size of Europe at the exact point of neutral gravity between the Earth and the Sun.

They all seek to have a temporary cooling effect on a specific area, but the one that has generated most interest for being relatively low cost, technically easy to deploy, and for having a global reach is stratospheric aerosol injection. The idea would be to release sulphate aerosols – other substances are being studied –  into the lower stratosphere to mimic a volcanic eruption. With enough substance released and maintained over time, it could reset the average global temperature to pre-industrial levels, according to experts.

Moral hazard or imperative?

But fiddling with the Earth’s systems can have serious implications, especially from such a large-scale intervention. Releasing sulphate into the stratosphere, for example, could have side-effects on the ozone layer. On top of that, the cooling down effect would be randomly and unequally distributed, with some regions being at a disadvantage to others.

And the political debate is far from settled as scientists and NGOs warn that it could detract governments from efforts to nip CO2 emissions in the bud.

“This discussion will delay and it will derail all existing climate policy programmes. It will demobilise politicians and demobilise businesses and might also demobilise citizens,” Frank Biermann, professor of global sustainability governance with the Copernicus Institute of Sustainable Development at Utrecht University, Netherlands, told the audience.

Professor Chukwumerije Okereke, director of the Center for Climate and Development at Alex Ekwueme Federal University Ndufu-Alike Nigeria, who has been working with African states in designing their national climate action plans, expressed fear and anger at the consideration of SRM when only 16 per cent of those plans had ever been funded.

“I have gone around Southern African heads of state, [telling them] ‘you have to engage with climate change, because it presents an opportunity for you to build climate resilience, infrastructure, and develop in a cleaner way’. They are now turning to me and [saying], ‘you sold us a lie. We believed you, we prepared the plans, we didn't get the money’,” Okereke said at the event. He denounced  SRM technologies as “delay tactics” to “buy time for more pollution” that would only endanger Africa’s economic development.

While agreeing that mitigating climate change should be the priority, Janos Pasztor, executive director of Carnegie Climate Governance Initiative, insisted on the bleak outlook of even the most optimistic projections of the International Governmental Panel on Climate Change (IPCC).

“Solar radiation modification cannot solve the climate crisis, let's be absolutely clear. The only thing that can solve the climate crisis is emission reductions and removing the excess carbon from the atmosphere,” he said at the event. “But we know from the IPCC’s latest information that all that emission reductions and carbon removal is taking time. And even under the most optimistic scenarios.”

Panellists discuss solar engeneering at an event at GESDA's science and diplomacy anticipation summit 2022. (Credit: Geneva Solutions/Michelle Langrand)

Pasztor said that instead of  discussing SRM as a “moral hazard”, it should be viewed as a “moral imperative” to begin planning for the use of SRM as a complementary measure alongside mitigation and adaptation efforts. He added that the impacts of climate change would be far worse than any side-effects that research has warned about so far.

Governments taking interest

For Biermann, the risks posed by SRM are too dangerous to fuel the discussion and “normalise” it, especially when there is no authoritative body to set the rules of the game.

“There is, right now, no plausible governance system by which these technologies can ever be regulated at the international level,” said Biermann. “If you just watch the news today, you have war in Ukraine, we have Putin, we have the Chinese, we have the Americans and NATO, maybe you have [the start of] a nuclear war in certain places. Can anybody imagine that these countries together would run a solar geoengineering programme with 1,000 aeroplanes for 50 years?”

Using aircraft to release aerosols every so often is one of the scenarios that has been suggested, while another one is the use of rockets. Biermann is among 350 scientists who have signed an open letter calling on governments to agree on a non-use agreement on SRM, including a commitment not to develop the technology.

Hans van der Loo, chairman of the Blue Cooling Initiative, who was in the audience, compared the move to “forbidding books”. The research institute-led project advocates for the cloud brightening method, which according to van der Loo is less effective but easier to control its effects by localising it and politically more viable.

Biermann defended the initiative arguing that “research freedom is extremely important, but there are many issues [for which] governments have decided for a very good reason to limit technology development”, citing chemical weapons, mining in Antarctica and human cloning.

But a number of multilateral fora have decided to delve into the thorny issue, including the UN Environment Assembly and more recently the UN special rapporteur on the human rights impact of climate change. Pasztor told Geneva Solutions that he saw the UN General Assembly as a good starting point for the conversation and suggested there might be growing interest in New York to begin a discussion.

Okereke was sceptical about multilateral discussions, suspecting that African voices would not be heard, as past negotiations had shown. “We [have not recovered] from the Cop of Copenhagen, where African heads of state were locked out of the room where the final deal was done. So I fear that even if somehow anybody is able to manufacture some kind of effective solar radiation management measures, African heads of state and government will not be part of the decision making platform,” he said.

Sikina Jinnah, a professor at the University of California who has been conducting research on the status of the public conversation around SRM, pointed out at the event that the global South has been largely left out of the conversation, with most scientific research as well as public opinion surveys coming from North America or Europe.

The upcoming climate summit in Egypt in November, which has been dubbed the African Cop, will show if the region is able to put its foot down and set its agenda before richer countries that have been stifling discussions for example on the controversial issue of compensation for climate impacts, also known as loss and damage.