Overview
- Columbia University researchers report that stratospheric aerosol injection would be far more difficult, risky, and costly to execute than most modeling studies indicate.
- Outcomes depend strongly on where, when, and how particles are released, with latitude a key factor and poorly coordinated efforts risking monsoon and jet stream disruption as well as ozone harm.
- Sulfate-based approaches, often modeled because volcanic eruptions cool the planet, carry documented side effects including altered rainfall patterns, stratospheric warming, ozone depletion, and potential acid rain.
- Many proposed mineral alternatives face supply and economic constraints, with diamond infeasible, cubic zirconia and rutile titania likely to strain supply chains, and only calcium carbonate and alpha alumina abundant enough to consider.
- At required sub‑micron sizes, candidate minerals tend to clump into larger aggregates that scatter less sunlight and add uncertainty, and the authors say effective risk reduction would require centralized international coordination that is unlikely.