This is a 2D energy-balance cross-section, not a rendered globe: the top strip shows a beam of sunlight crossing a stratospheric haze layer whose thickness tracks injected aerosol mass, and the strip chart below plots stratospheric mass, radiative forcing and temperature anomaly over simulated decades — the same governing equations as the 3D version, read as a time series instead of a rotating sphere.
dM/dt = injectionRate − M/τ (stratospheric aerosol mass)
AOD = k₁·M (optical depth ∝ mass)
Forcing = −k₂·AOD (W/m², cooling)
C·dT/dt = Forcing − λ·(T − T₀) (temperature relaxes toward new balance)
- Injection rate — how much SO₂ the fleet disperses per year (Pinatubo 1991 emitted roughly 10 Tg in one eruption, then decayed away — a sustained SAI program must keep re-injecting).
- Aerosol residence time (τ) — how long a droplet survives in the stratosphere before gravitational settling and washout remove it; larger particles and lower altitudes fall out faster.
- Termination shock — stopping injection abruptly lets the aerosol mass (and its cooling) decay away over roughly one residence time while any greenhouse forcing it was masking is still there, so temperature snaps back toward the unmitigated baseline far faster than it fell.
Real-world relevance: SAI is the most-studied solar radiation management (SRM) proposal precisely because volcanic eruptions are a natural analogue — but termination shock and regional rainfall shifts remain open, actively debated risks, and SAI only cancels warming, it never touches the CO₂ or ocean acidification driving it.