Controversial geoengineering research, including a plan to study blocking sunlight, received $75 million in funding from the UK government’s Advanced Research and Invention Agency (ARIA), which some scientists warn could be just as dangerous as the climate change it seeks to combat.
Proposals to geoengineer humanity’s way out of the impending climate crisis span 21 projects, from sunlight-reflecting clouds to thickening arctic ice. The funding comes under ARIA’s Exploring Climate Cooling programs, a five-year initiative aimed at holding off the tipping point of the impending crisis.
Advanced Research and Invention Agency
ARIA was announced in 2021 as the UK’s answer to the US Defense Department’s Defense Advanced Research Projects Agency (DARPA) and has been active since 2023. The agency’s £800 budget funds risky yet potentially groundbreaking technologies in areas like climate, AI, and neurotechnology, leaving more conventional and slow-paced research to the UK Research Initiative, the country’s other public science funding organization.
The shadowy agency became a target of controversy early on over its lack of transparency, after being declared exempt from freedom of information requests. The News Media Association, a UK media organization with members that include The Guardian and The Daily Mail, issued a statement in 2021 calling for the UK government to reverse ARIA’s immunity from freedom of information requests.
Geoengineering Controversy
Now, ARIA is wading further into controversial territory with its recent funding of geoengineering projects. Despite warnings of climate catastrophe, many experts have expressed concerns over whether relying on geoengineering as a solution could produce outcomes worse than the problem at hand.
Last year, Harvard University canceled a project in Sweden to dim the sun by introducing particles into the atmosphere after local residents became concerned about the longer-lasting repercussions. On May 7, 2025, Florida also took legislative action to ban geoengineering.
Mark Symes, a University of Glasgow electrochemist who leads ARIA’s Exploring Climate Cooling programs, explained that any proposed concepts are only stop-gap measures to curb the planet’s slow progress toward reaching a global climate tipping point, buying time to address root causes like carbon emissions.
“We want to keep this research in the public domain,” said Piers Forster of the University of Leeds, who chairs a committee that monitors climate projects for ARIA.
“We want it to be transparent for everyone,” Forster said.
Exploring Climate Cooling Programs
The program received 120 proposals, which were eventually reduced to 21 selected across five categories. Those categories include thickening ice sheets, brightening clouds, probing the relationship of cirrus clouds and warming, determining whether particles in the stratosphere will reflect sunlight, and exploring whether a space-based sunshade could cool the Earth. Five of these projects will include real-world outdoor experiments.
Peter Frumhoff, a science policy adviser at the Woodwell Climate Research Center in Falmouth, Massachusetts, says that “building trust will be essential” in conducting such research.
“I would be opposed to outdoor experiments being funded by any nation that isn’t aggressively and seriously reducing its own emissions,” Frumhoff said.
“Solar geoengineering has enormous and troubling implications for global society,” said Prof Raymond Pierrehumbert at the University of Oxford, in a statement published by The Guardian. “The UK funding sets a dangerous precedent for other governments to jump on the bandwagon [and] it is the height of folly to open the door to field experiments in the absence of any national or international governance.”
First Experiments
One of the earliest outdoor experiments undertaken is arguably the most controversial: Solar Radiation Modification (SRM), which seeks to block sunlight and thereby cool the Earth’s surface. Tests involving the proposed technology will send balloons full of limestone and dolomite dust 15-50 kilometers into the stratosphere to study how the material responds and to determine the practicality of blocking sunlight by filling the stratosphere with particles.
Lower atmosphere SRM concepts include brightening clouds in the troposphere to reflect sunlight away from the surface. Researchers have already determined that cloud brightening off Namibia’s coast could lead to droughts in the Amazon.
Conceptually, the idea for this approach was modeled after the cooling effects of natural disasters such as volcanic eruptions, which eject large volumes of particulates into the air. Still, there is uncertainty over whether greater climate instability could result from such human interventions. Right now, major concerns linger over whether reducing average global temperatures could lead to even more severe and disruptive weather events worldwide.
Meanwhile, in Norway and Canada’s northern latitudes, the Centre for Climate Repair will attempt to pump water from beneath ice sheets onto their surfaces, testing whether the water will freeze and thicken them.
“We’re going to see whether we’ve actually been able to grow more sea ice in the Arctic winter,” said Shaun Fitzgerald at the Centre for Climate Repair. Early results from work Fitzgerald’s team did last year, before receiving ARIA funding, showed ice growth of “about half a metre”, he says.
In the future, ARIA pledges to scale up the proposed ice thickening project only if these first two experiments demonstrate that the methodology proposed is ecologically sound. Despite this, several scientists, such as University College London researcher Julienne Stroeve, question the practicality of such interventions, as well as their potential impact on local ecosystems.
“I do not think this is feasible at any real scale needed,” Stroeve said.
Ryan Whalen covers science and technology for The Debrief. He holds an MA in History and a Master of Library and Information Science with a certificate in Data Science. He can be contacted at ryan@thedebrief.org, and follow him on Twitter @mdntwvlf.