Planetary Engineering: The Most Neglected Lever on Climate?

​Climate change gets enormous attention; deliberately engineering the planet to counteract it gets almost none. Yet solar radiation modification (SRM), injecting aerosols into the stratosphere, brightening marine clouds, could offset a large fraction of warming within years, at a cost measured in billions rather than trillions. Ocean iron fertilization and enhanced rock weathering offer analogous levers for carbon drawdown. By the standard importance–tractability–neglectedness test, this may be one of the most under-explored areas in climate.

​It's also one of the most dangerous. SRM is cheap enough that a single nation, or a single billionaire, could deploy it unilaterally, imposing planetary consequences on everyone (the "free driver" problem). Governance is nowhere close to ready. If that structure sounds familiar, it should: like advanced AI, geoengineering is a powerful dual-use technology where capability is outpacing oversight, and where the hard questions are as much about coordination as about engineering.

​Join us at Mox for a discussion of the science, the risks, and the governance gap, and whether this deserves a place on the EA priority list. No climate background needed; skepticism welcome.

​RECOMMENDED READING LIST — Geoengineering Salon

​No climate background needed. Ordered most accessible first.

​CORE

1. ​SRM360 explainers → srm360.org

2. ​Stardust startup coverage → technologyreview.com/2025/12/11 or heatmap.news/climate-tech/stardust-geoengineering

3. ​Halstead (2018), SAI research and existential risk → https://doi.org/10.1016/j.futures.2018.03.004

4. ​Biermann et al. (2022), The case for an international non-use agreement → https://doi.org/10.1002/wcc.754

5. ​Parson & Keith (2024), Solar geoengineering: History, methods, governance, prospects → https://doi.org/10.1146/annurev-environ-112321-081911

6. ​How much SO2 would it take to buy us time?

​OPTIONAL — MORE TECHNICAL

1. ​Smith & Wagner (2018), SAI tactics and costs → https://doi.org/10.1088/1748-9326/aae98d

2. ​Henry et al. (2025), Marine cloud brightening to cool the Arctic → https://doi.org/10.1029/2025EF006508

3. ​Parry et al. (2026), SAI, land carbon storage, and the Amazon → https://doi.org/10.5194/esd-17-387-2026

4. ​Bach et al. (2023), CO₂ removal with iron fertilization → https://doi.org/10.1029/2023GB007754

​OPTIONAL — FRONTIER

1. ​Sánchez & McInnes (2015), Space-based sunshades at L1 → https://doi.org/10.1371/journal.pone.0136648

2. ​Keefer et al. (2023), Seabed-anchored curtains for ice sheets → https://doi.org/10.1093/pnasnexus/pgad053

​OPTIONAL — FICTION

1. ​Neal Stephenson, Termination Shock (2021)

2. ​Kim Stanley Robinson, The Ministry for the Future (2020)