Greenhouse: One vs Two Slabs

A stack of blackbody isothermal atmospheric shells in radiative balance with shortwave absorption (1−α)S/4 at the surface illustrates how adding layers increases surface temperature while keeping effective emission temperature tied to outgoing longwave. Compare one shell (σT₁⁴ = 2S₀) with two shells (σT₂⁴ = 4S₀) in the same normalized flux units.

Who it's for: Climate physics introductions contrasting gray-slab counts.

Key terms

  • Greenhouse effect
  • Energy balance
  • Albedo
  • Effective temperature

S₀ = (1−α)S/4 is absorbed shortwave per unit area in this cartoon; see also the single gray-slab simulator in Astronomy for emissivity-based variants.

Live graphs

How it works

Analytic comparison of effective temperature versus surface temperature for idealized one- and two-shell greenhouse models at the same planetary albedo.

Frequently asked questions

Why black shells instead of emissivity sliders?
To keep the algebra closed-form; see the astronomy single-slab simulator for emissivity-based gray variants.