About the model
A zonal energy-balance model over 18 equal-area bands. Longwave radiation uses a semi-grey
two-stream fit anchored to modern Earth (240 W/m²), Venus (161 W/m²) and the
Simpson–Nakajima runaway limit of 283 W/m² — which the fit reproduces rather than
imposes, so the runaway greenhouse emerges from the physics.
Slow processes run on the same accelerated clock: the carbonate–silicate thermostat
(~1 Myr), snowball CO₂ build-up (5–50 Myr), and hydrogen escape (10⁸–10⁹ yr to lose an ocean).
Physics advances on simulated time only — the trajectory is identical at any frame rate.
Source & references
Free software under the GNU GPL v3 or later, with
no warranty. The page you are running is its own source: every module
arrives unminified, and the repository above is the corresponding source in full.
Surface maps are third-party and keep their own terms.