Microbial Desert Geoengineering

China has reportedly begun dropping specially selected cyanobacteria over dunes to form living crusts that stabilise sand, enabling later plantings and potentially altering large desert ecosystems at continental scales. The method is cheap, rapid to scale with aerial dispersal, and is being linked to transnational 'Great Green Wall' projects in Africa and Mongolia. — If scaled, microbial crusting transforms restoration and geoengineering policy: it creates opportunities for desert reclamation and carbon drawdown but also triggers cross‑border ecological, biosafety and governance risks that require international rules and transparency.