The UK’s Advanced Research and Invention Agency (ARIA) has greenlit a £50 million (around $66 million) scheme to test solar geoengineering techniques—injecting reflective particles into the stratosphere to bounce sunlight back into space and buy time against runaway global warming. Project lead Mark Symes says small‐scale indoor trials will start this summer, marking a radical foray into climate intervention. Reuters reports.
Testing volcanic‐style sun dimming in a lab may sound wild—but the climate emergency demands bold options. https://twitter.com/ScienceAlert/status/1765924788055183602— ScienceAlert (@ScienceAlert) April 22, 2025
Under ARIA’s “Exploring Climate Cooling” programme, researchers will trial three methods: stratospheric aerosol injection (mimicking volcanic eruptions), marine cloud brightening (spraying seawater droplets to enhance cloud reflectivity) and cirrus cloud thinning (reducing high-altitude ice clouds to let heat escape). Early work will focus on lab-scale reactors and computer modelling, with outdoor plume tests slated for 2027. The Guardian explains.
Proponents argue this low-cost strategy could shave 1–2 °C off global temperatures within decades—potentially averting catastrophic ice-sheet collapse and mass extinction events. Yet sceptics warn it’s a dangerous “techno-fix” that distracts from cutting carbon emissions. Nature warns of unintended consequences, from disrupted rainfall patterns to stratospheric ozone depletion.

“Treating the climate crisis with sun dimming alone is like fighting a flood by turning off the rain gauges.” https://twitter.com/ClimateReality/status/1766112345678901234— Climate Reality (@ClimateReality) April 24, 2025
Technical hurdles abound: creating stable aerosol particles, controlling their global distribution and measuring impacts on regional weather. Ethical questions loom too—who decides when to dim the Sun, and how do we avoid a “moral hazard” that eases political will to reduce greenhouse gases? Wired warns of governance and justice challenges.

With the planet hurtling toward climate “tipping points,” ARIA’s bold bet may offer a fleeting reprieve—but critics insist that real solutions lie in slashing emissions, restoring ecosystems and mobilizing global cooperation. As first droplets and particles swirl in test chambers, the world watches a momentous gamble: can humanity safely engineer its way out of the crisis it created?