Uncertainty
Medium
Decision relevance
Low
Resolvability scale
Long-term sustained deployment
Terrestrial carbon uptake includes changes in Net Primary Productivity (NPP) and carbon storage in permafrost amongst others. There is a significant uncertainty in the impact on plants of simultaneously changing temperature, CO2 concentration and diffuse-to-direct light ratio, as well as due to effects on forest fires.
Metric
Terrestrial carbon uptake decreases/remain the same under SAI relative to a no-SAI future
Uncertainty
Medium
There is significant uncertainty in land carbon cycle projections of the land carbon sink (Aurora et al., 2020), but the metric is relatively wide so the level of uncertainty balances out to medium.
Decision relevance
Low
These amounts are relatively very small compared to the impact anthropogenic emissions have.
References
7Impact of idealized future stratospheric aerosol injection on the large-scale ocean and land carbon cycles(Tjiputra et al., 2015)
Climate engineering and the ocean: effects on biogeochemistry and primary production(Lauvset et al., 2017)
Carbon Cycle Response to Stratospheric Aerosol Injection With Multiple Temperature Stabilization Targets and Strategies(Zhao et al., 2024)
An overview of the Earth system science of solar geoengineering(Irvine et al., 2016)
Change in negative emission burden between an overshoot versus peak-shaved stratospheric aerosol injection pathway(Baur et al., 2025)
Carbon–concentration and carbon–climate feedbacks in CMIP6 models and their comparison to CMIP5 models(Arora et al., 2020)
The interaction of solar radiation modification with Earth system tipping elements(Futerman et al., 2025)