Experts War-Game Solar Geoengineering, Exposing Risks From 0.5-Degree Cooling
Updated
Updated · Ars Technica · Oct 13
Experts War-Game Solar Geoengineering, Exposing Risks From 0.5-Degree Cooling
2 articles · Updated · Ars Technica · Oct 13
Summary
A London simulation brought together a couple dozen diplomats, scientists, military figures and former officials to test how the world might respond to solar radiation modification.
The exercise aimed to head off an uncontrolled race to deploy planet-cooling tools that could reflect sunlight away from Earth but carry vast unknown risks.
Models discussed in the war game suggest the technology could cool the planet by half a degree or more, echoing major volcanic eruptions, while drying sub-Saharan Africa and intensifying Atlantic tropical storms.
Participants also confronted a key instability: the cooling would last only while geoengineering continued, and stopping it could trigger a sharp temperature rebound with hard-to-predict global effects.
If humanity hacks the atmosphere to cool the Earth, what catastrophic shocks await if the system fails?
Could a single rogue nation unilaterally block the sun and trigger a devastating global climate war?
Will the cheap cost of solar geoengineering become the ultimate excuse to abandon critical carbon emission cuts?
Solar Geoengineering at the Brink: Lessons from the 2026 War-Game, Geopolitical Risks, and the Global Governance Crisis
Overview
The report highlights how efforts to govern solar geoengineering are facing major challenges as commercial startups, governments, and civil society groups clash over control and safety. A 2026 war-game in London, backed by the UK government, showed that global cooperation quickly breaks down when national interests and distrust take over, with intelligence accusations and secret funding undermining trust. Technical risks like ozone depletion, acid rain, and sudden warming if deployment stops add to the danger, especially for vulnerable regions. Meanwhile, private companies push ahead with unregulated experiments, prompting new bans and public backlash. Without strong, inclusive international rules, the risk of conflict and environmental harm grows.