Overview

• An international team led by glaciologist Martin Siegert, writing in Frontiers in Science, concludes that none of five prominent polar interventions passes scrutiny or could be deployed fast enough to meaningfully affect the climate crisis.
• The assessment examined sea-ice thickening or reflective beads, seabed sea curtains, stratospheric aerosol cooling, subglacial water pumping, and ocean nutrient fertilization.
• The authors warn of intrinsic environmental harm, citing risks such as disrupted marine habitats, altered climate patterns and potential contamination, and they highlight major governance gaps in polar regions.
• Estimated costs begin at least at $10 billion per approach, with a 50-mile sea curtain projected around $80 billion over a decade, and the concepts remain untested at the necessary scale.
• The findings sharpen a divide over next steps, as a limited University of Cambridge trial to pump seawater onto Arctic ice — funded by the UK’s ARIA — is reported as planned for this winter.