geoengineering

A proposal for a giant space sunshade — a large structure placed between Earth and the Sun to block a fraction of sunlight — is being discussed as a way to reduce global temperatures and complement efforts against climate change. The idea, sometimes called solar geoengineering, remains speculative and would face enormous engineering, cost and governance challenges, but it is drawing attention as global warming concerns grow.

A new report from the scientific community proposes research into a so-called planetary sunscreen — injecting reflective particles into the stratosphere to reduce the amount of sunlight reaching Earth and lower global temperatures. The idea, known as solar geoengineering, is drawing attention in Brazil and beyond, with supporters saying it could buy time against warming while critics worry about unpredictable side effects.

The World Economic Forum is calling for an internationally coordinated roadmap to govern geoengineering and other climate intervention technologies. As interest grows in techniques such as solar radiation modification and carbon removal to limit warming, the organisation argues that without shared rules, research and potential deployment risk proceeding unevenly and without accountability, raising concerns among scientists, policymakers and climate advocates about governance, ethics and unintended consequences.

The Carnegie Endowment for International Peace has published an analysis titled 'Planetary Power: Geoengineering and the New Geopolitics of Climate Intervention', examining how large-scale climate intervention technologies could reshape international power dynamics. The piece argues that geoengineering, including solar radiation management and carbon removal, is moving from scientific debate into the realm of global strategy, raising questions about governance, unilateral action and conflict between states over who controls the planet's thermostat.

Futurist Bryan Alexander is running through scenario exercises on geoengineering, exploring what could happen if governments or companies deliberately intervene in the climate system. The exercise highlights unresolved questions about who would decide to deploy technologies like sunlight reflection, how countries would coordinate, and what unintended consequences might follow. Interest comes amid growing debate over whether geoengineering should be researched or ruled out as climate targets slip.