The UK’s gamble on solar geoengineering is like using aspirin for cancer | Raymond Pierrehumbert and Michael Mann

Injecting pollutants into the atmosphere to reflect the sun would be extremely dangerous, but the UK is funding field trials

Some years ago in the pages of the Guardian, we sounded the alarm about the increasing attention being paid to solar geoengineering - a barking mad scheme to cancel global heating by putting pollutants in the atmosphere that dim the sun by reflecting some sunlight back to space.

In one widely touted proposition, fleets of aircraft would continually inject sulphur compounds into the upper atmosphere, simulating the effects of a massive array of volcanoes erupting continuously. In essence, we have broken the climate by releasing gigatonnes of fossil-fuel carbon dioxide, and solar geoengineering proposes to fix" it by breaking a very different part of the climate system.

Raymond T Pierrehumbert FRS is professor of planetary physics at the University of Oxford. He is an author of the 2015 US National Academy of Sciences report on climate intervention

Michael E Mann ForMemRS is presidential distinguished professor at the University of Pennsylvania. He is the author of Our Fragile Moment: How Lessons from Earth's Past Can Help Us Survive the Climate Crisis