Trials will test ways to block sunlight and slow climate crisis that threatens to trigger catastrophic tipping points

Real-world geoengineering experiments spanning the globe from the Arctic to the Great Barrier Reef are being funded by the UK government. They will test sun-reflecting particles in the stratosphere, brightening reflective clouds using sprays of seawater and pumping water on to sea ice to thicken it.

Getting this “critical missing scientific data” is vital with the Earth nearing several catastrophic climate tipping points, said the Advanced Research and Invention Agency (Aria), the government agency backing the plan. If demonstrated to be safe, geoengineering could temporarily cool the planet and give more time to tackle the root cause of the climate crisis: the burning of fossil fuels.