Experts in the field of solar radiation modification (SRM) are well versed with the pros and cons of the technology, but what does the general public think about SRM?

Solar radiation modification technology sounds a little bit like a science fiction film where humans have figured out how to (sort of) control the weather.

What is Solar Radiation Modification?

SRM is an intervention or device that reflects a small amount of sunlight back into space, for example by injecting reflective aerosols into the stratosphere, which results in reduced global temperatures.

There are at least four possible types of SRM currently being studied and tested around the world:

Stratosphere injection:
using airplanes or balloons to inject sulfur particles into the stratosphere that reflect sunlight

Cloud brightening:
spraying seawater into low clouds above the sea so that the cloud becomes more reflective, remains intact for longer and can reflect more sunlight

Thinning clouds:
injecting ice cores into cirrus clous so that they will dissipate more quickly and retain less heat radiatiing from the earth

Space mirrors:
deploying large arrays of satellites with mirrors into space that block sunlight

Stratospheric injection and other SRM interventions are not without controversy. Experts have argued that they have the potential to limit global warming to 1.5 °C and reduce some of the worst consequences of global warming, but there are also concerns that they would do so by changing the natural precipitation cycle which could exacerbate droughts and flooding.

SRM in the news

SRM has been in the headlines quite a bit lately: The New York Times published a story and podcast episode earlier in April about a California experiment with cloud brightening, and here in the Netherlands, in an in-depth article in NRC, journalist Laura Wismans dug into the nuances of SRM.

The NRC story poses one core question: can (and should) mankind manipulate the amount of sunlight that earth receives and use it as a weapon against climate change?

The story makes the point that instead of using SRM to buy more time to tackle the source of global warming – greenhouse gas emissions from burning fossil fuels – it risks being treated as a more permanent solution that would only slightly limit rising temperatures. If it is seen as a solution unto itself, SRM could end up as a band aid on a gaping wound, instead of an intervention that could complement mitigation efforts.

“Part of the controversy can be chalked up to extremely low confidence in the ability to organise something so far-reaching on a global scale while ensuring equal say in decision making from often strongly opposing interests”, the story reads.

The potential regional effects and scepticism about the ability to have a coordinated and equitable approach is why “advocates of SRM research say that they want to know more about it”, the article reads. “Potential harmful effects [of SRM] are not necessarily a barrier [to implementing it], because allowing climate change to continue to worsen is already causing harm in the present.”

Public views about SRM

Given the possible consequences of the technology, research is necessary to better understand what public perceptions of SRM actually are. That is precisely what our fellow researcher and lead author Nadja Contzen, along with Environmental Psychology Groningen researchers Linda Steg, Goda Perlaviciute, Chieh-Yu Lee and Gabriel Muiños Trujillo (and 34 other authors from other knowledge institutions), sought to do in their paper, “Public opinion about solar radiation management: A cross-cultural study in 20 countries around the world”, published in Climatic Change on 29 March.

The paper is the most comprehensive global survey of public views about SRM to date, and such thorough canvassing is an approach commensurate with the global implications of SRM. The survey reached respondents in 20 countries across all inhabited continents, including five countries from the Global South and five ‘non-WEIRD’ (Western, Educated, Industrialized, Rich and Democratic) countries from the Global North. Respondents included 2,248 members of the general public and 4,583 students.

Advantages and disadvantages

Which advantages and disadvantages do average citizens see when it comes to SRM? The researchers found that while many authorities on SRM agree that it could potentially limit global warming in most countries, study respondents only perceived this advantage to a small extent.

On average, participants also thought that SRM would have marginally negative impacts on humans and nature. The more negative impacts on humans and nature people associated with SRM, the less acceptant they were of it. Similarly, acceptance of was SRM lower the more that people believed it would not limit global warming.

Two other issues that study participants were less concerned about than experts were SRM’s failure to address the root cause of global warming, namely greenhouse gases, and that SRM adoption could decrease political and citizen efforts to mitigate global warming.

On the other end of the spectrum, the less that respondents said they believed in global warming, the less that they accepted SRM. Seeing the technology as too expensive also led to less acceptance.

The Global South

Similar to experts, study respondents also perceived that the costs and benefits of SRM would be unequally distributed between countries: the more that participants felt this way, the less that they accepted it.

Striving for equal representation, including those countries that may face the worst effects of either climate change or any interventions, is something that assistant professor of climate change and policy at Wageningen University Ina Möller calls for in the NRC article. She says that not everyone has an equal voice as it stands.

“Right now, the physics side of research is very dominant; perspectives from social and ecological sciences are less present. And the southern hemisphere, which is much more vulnerable to SRM impacts, is barely represented at all”, Möller says.

With that in mind, it is notable that the Climatic Change research paper found that acceptability of SRM was actually relatively higher in the Global South countries than the Global North. The paper is among the first attempts to enrich policy-making on SRM with insights from social sciences and public perceptions research from many different countries, including from the Global South.

Overall, the scientists generally found that people were conditionally yet reluctantly acceptant of the potential need for deploying SRM technology as a last resort if we don’t manage to limit climate change.

You can find the full study in Climatic Change here.

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