The United Kingdom government has firmly ruled out deploying solar radiation management (SRM) technologies aimed at reducing global temperatures by reflecting sunlight away from the Earth. This position was outlined in a policy document published by the Department for Energy Security and Net Zero, now overseen by Mariatta Fahnbulleh.

SRM encompasses a range of experimental approaches, including cloud brightening, stratospheric aerosol injection, and the deployment of orbital mirrors. These techniques have gained heightened attention following a summer marked by unprecedented heatwaves across Europe. Despite growing international interest, the technologies remain controversial due to concerns about potential disruptions to weather systems, with scientific bodies such as the Royal Society warning of risks like drought in some regions.

Former energy secretary Ed Miliband, responding to earlier claims about imminent SRM deployment, dismissed them as baseless conspiracy theories. The current government maintains that its priority lies in aggressively cutting greenhouse gas emissions and adapting to climate change impacts rather than resorting to geoengineering solutions.

Although the government is ruling out the operational use of SRM, it continues to finance research into potential Earth cooling methods. Through the Advanced Research and Invention Agency (Aria) — an innovation fund established under former adviser Dominic Cummings — £56.8 million has been allocated to investigate techniques such as electrically charging or injecting saltwater into clouds to enhance their reflectivity. Officials emphasized that Aria’s funding does not support experiments involving harmful substances, large-scale field tests, or activities that could lead to the deployment of SRM technologies.

Experts have generally welcomed the cautious stance. Shaun Fitzgerald, director of the Centre for Climate Repair at the University of Cambridge, described the government’s approach as sensible given the current high levels of uncertainty. However, he noted that should efforts to reduce emissions fall short, understanding alternative temperature control options will be important.

Meanwhile, some scientists privately express concern over the potential for commercial entities to independently advance geoengineering efforts without adequate oversight. Notably, Stardust, a US-Israeli startup, recently secured $75 million in funding to pursue stratospheric aerosol injection technology modeled on volcanic cooling effects.

The government reaffirmed its position that research into these cooling approaches does not lessen the imperative for decarbonization. Officials stressed that no geoengineering method can replace the urgent need to drastically reduce greenhouse gas emissions to mitigate the worst impacts of climate change.