Dimming the sun by injecting particles into the sky will not dial back climate change – it will introduce massive new disruptions and further disturb already disrupted climate systems, with likely disastrous impacts on regional climates, ecosystems and peoples’ livelihoods.

If injections are stopped abruptly, decades or centuries worth of pent-up global heating would result in spiking temperatures almost immediately. Such a termination shock would rip earth’s societies and ecosystems apart. If we start relying on solar geoengineering we would likely have to continue for thousands of years, even as catastrophes mount.

Solar geoengineering would require functional global governance systems for thousands of years – an impossible requirement. It would also create risks for international conflict and wars. Who would control the thermostat? What will happen when superpowers disagree? 

As people are starting to realise that society can and must decarbonize to real zero as quickly as possible, and that we already have the technology to do so, solar geoengineers provide fossil fuel producers and emitters with yet another excuse to delay and evade.

Solar geoengineering research is advanced by a limited clique of predominantly white, male researchers at elite universities, and wealthy philantropists based in the Global North, while impacts would be felt first and hardest by indigenous peoples and communities in the Global South.

Advancement of solar geoengineering technology must be halted now, before the idea becomes normalised, and before scientific careers, research funds, and vested and commercial interests become more consolidated, forcing the world down a slippery slope towards eventual deployment.