UK scientists are preparing to conduct outdoor geoengineering tests as part of a £50 million initiative funded by the government. According to the Advanced Research and Invention Agency (Aria), the experiments will be limited in scale, thoroughly monitored, and are aimed at generating essential data to evaluate the feasibility of geoengineering technologies. An additional £11 million research project places the UK among the global leaders in this controversial field.
Geoengineering strategies, especially solar radiation management (SRM), are designed to cool the planet by reflecting sunlight away from Earth. Examples include dispersing reflective particles in the atmosphere or enhancing cloud brightness using seawater sprays. Although potentially effective at temporarily lowering temperatures, these methods remain contentious due to concerns about environmental side effects and the ethical implications of altering the climate.
Supporters argue that SRM research is crucial, especially given the ongoing failure to significantly cut carbon emissions and the series of record-breaking hot years. They believe geoengineering could serve as a stopgap measure while deeper emissions cuts are pursued. However, critics worry that it could reduce urgency to address fossil fuel use and might lead to dangerous changes in weather patterns, such as disrupted rainfall needed for agriculture.
Prof. Mark Symes, leading the Aria programme, emphasized that the rising risk of climate tipping points—like the breakdown of ocean currents or melting of polar ice—makes studying geoengineering a priority. He said that while models and lab research have value, real-world experiments are necessary to understand the actual impact and viability of proposed technologies.
He assured that no harmful substances would be released during the trials, and each experiment would undergo environmental assessments and community consultations. Details of the specific projects will be released soon.
Still, not everyone supports the initiative. Some scientists have criticized SRM as a “dangerous distraction” from reducing emissions, comparing it to treating cancer with aspirin.
Separately, the UK’s National Environment Research Council (Nerc) announced a £10 million geoengineering research effort focused on modelling and historical data, rather than outdoor testing. According to Nerc’s Kate Hamer, the goal is to provide unbiased scientific evidence without endorsing any specific approach.
Global funding for geoengineering remains relatively modest, but with the U.S. pulling back under past political leadership, the UK may become the top funder. Dr. Pete Irvine from the University of Chicago cautioned that geoengineering should not be seen as a replacement for emissions cuts.
Prof. Jim Haywood from the University of Exeter, involved in the Nerc project, said that if proven safe and effective, scaling up SRM could be possible within a decade. He added that recent extreme temperatures highlight the urgency of keeping all options open.
No global agreement currently exists to regulate large-scale geoengineering, prompting calls for international collaboration and caution. Dr. Sebastian Eastham of Imperial College London noted that SRM could have geopolitical ramifications, and part of their research will involve engaging with international perspectives to explore the global consequences.
Eastham also suggested the UK’s research may help eliminate certain technologies from consideration, allowing efforts to focus on the safest and most effective methods.
