Policy Brief: Safeguarding the polar regions from dangerous geoengineering

This policy brief summarizes for policymakers the extensive assessment contained in the peer-reviewed paper Siegert et al., 2025 “Safeguarding the polar regions from dangerous geoengineering: a critical assessment of proposed concepts and future prospects”. This assessment was published in Frontiers in Science on 09 September 2025. Content of this policy brief has been approved by the co-authors. For more information and references, please see the original open-access paper at https://doi.org/10.3389/fsci.2025.1527393. Geoengineering approaches have gained increasing attention as proposed solutions to reduce the adverse effects of climate change, especially impacts from polar regions such as sea-level rise and permafrost thaw emissions. Our scientific assessment, by 42 leading polar and climate scientists, evaluated five proposed geoengineering concepts that focus on polar action. The assessment concludes that these methods are unlikely to work in avoiding climate impacts, would have potentially severe and unpredictable environmental and societal impacts, and would be prohibitively expensive or unfeasible in harsh polar conditions. It concludes that research efforts are better focused on decarbonising and, in the polar regions, on fundamental research that will underpin detailed understanding of processes driving observed and projected changes. The assessment reviews the following five proposed concepts:• Stratospheric aerosol injection (SAI) to increase reflection of the sun’s rays within the atmosphere to reduce warming temperatures• Construction of sea curtains to divert warm ocean water away from the margins of ice sheets to reduce melting and resulting sea-level rise• Whitening sea ice to increase its reflectivity and thickening it to increase its longevity, reducing sea ice losses and increasing the cooling impact of the Arctic Ocean• Removal of water from beneath fast-flowing regions of the polar ice sheets to slow down their flow into the ocean• Addition of iron to ocean water (OIF) to increase biological CO2 drawdown from the atmosphere