Fact-check: Debunking claims around the UK’s geoengineering experiments
Misinformation is once again swirling online following the UK government’s announcement that it will fund small-scale outdoor geoengineering experiments aimed at tackling climate change.
Geoengineering, a term that refers to deliberate, large-scale interventions in the Earth’s natural systems to counteract global warming, typically falls into two broad categories. The first is Solar Radiation Management (SRM), which seeks to reflect a fraction of sunlight back into space to cool the planet. The second is carbon dioxide removal, which involves extracting CO2 from the atmosphere.
The UK’s recent announcement focuses on the former. Reports indicate that approximately £56.8 million (€67 million) has been allocated to fund research into methods such as injecting sun-reflecting particles into the stratosphere and spraying seawater onto clouds to enhance their reflectivity. The initiative is supported by the Advanced Research and Invention Agency (Aria), which insists the experiments are limited in scope and are intended not only to explore technological viability but also the frameworks for international governance.
Despite these clarifications, social media platforms have been flooded with claims that the UK has been secretly engaging in geoengineering for years, with some suggesting the experiments are a covert attempt to control the population. These assertions often overlap with the thoroughly debunked “chemtrails” conspiracy theory, which alleges that aircraft contrails are laced with harmful chemicals dispersed over populations.
Independent fact-checking organisation EuroVerify consulted experts to examine the validity of such claims. Their conclusion was unanimous: there is no evidence to support them.
Jim Franke, a researcher at the University of Chicago’s Department of Geophysical Sciences, firmly stated, “It would be impossible to conduct large-scale weather modification experiments in secret. The quantity of aircraft required and the observable radiative effects would make such activities plainly visible through publicly available data.”
Similarly, Professor Wolfgang Cramer, a global ecology researcher at France’s National Centre for Scientific Research (CNRS), criticised the alarmist narratives circulating online. While acknowledging valid concerns surrounding geoengineering, Cramer rejected the notion of secret agendas. “Governments such as the UK are exploring this technology with the honest intention of addressing the climate crisis,” he said. “It’s important to understand this is a complex debate, not a matter of good versus evil.”
Both Franke and Cramer dismissed suggestions that the UK’s announcement is a smokescreen for years of covert SRM activities. They clarified that while cloud seeding—a practice designed to enhance rainfall—has been used in certain regions, it is not the same as SRM, which involves long-term manipulation of Earth’s radiation balance. “SRM is a planetary-scale effort and cannot be confused with localised weather modification,” said Cramer.
Franke added that although small-scale experiments and computer modelling have been conducted, it is implausible to believe governments have been running secret SRM operations. “The academic community publishes regularly on these topics, which unfortunately can be twisted into conspiracy fodder online,” he noted.
Why is geoengineering so controversial?
The global community’s slow progress in cutting greenhouse gas emissions has pushed some scientists to view geoengineering as a necessary backup plan. Yet the scientific community remains divided on its merits.
One concern is that investing in geoengineering could divert attention and resources away from decarbonisation, while others worry about the complexities of international governance. As Cramer pointed out, a global SRM scheme would need to be managed by an independent international body, potentially operating for decades, making it vulnerable to shifting political tides and unilateral withdrawal.
Additionally, experts caution against unintended environmental side effects. Franke warned that SRM could slow the hydrological cycle, leading to reduced rainfall in some regions. The full extent of these impacts remains uncertain, reinforcing the need for thorough research.
Despite these uncertainties, modelling suggests that moderate SRM interventions could mitigate many key climate risks, from extreme heat to ice sheet melting. However, Franke underscored that research should not equate to implementation, and any decision to deploy such technology must be made collectively by the global community using the best available science.