Chapter 8: The Greenhouse Effect

Model climate-relevant radiation physics from emissivity and albedo through planetary energy balance, then build the greenhouse mechanism with atmospheric absorption, reradiation, and feedback reasoning.

2 simulation entries

Simulation: Emissivity and Thermal Spectrum

Use radiation mode to compare how emissivity, object temperature, and surroundings temperature control emitted, absorbed, and net thermal power.

Appears in: 8.1 Radiation from Real Bodies

Heat Transfer + Radiation Lab

Area A (m^2): 2.00Beginning temp (deg C): 22.0End temp (deg C): -5.0Layer 1 thickness (cm): 6.0Layer 2 thickness (cm): 10.0Layer 1 conductivity k1 (W m^-1 K^-1): 0.92Layer 2 conductivity k2 (W m^-1 K^-1): 0.04

Composite wall and Fourier temperature profile

Total thermal resistance

1.4215 K/W

Interface temperature

21.38 deg C

Total heat rate q

18.99 W

Heat flux magnitude

9.50 W/m^2

Move between conduction and radiation views to compare Fourier temperature-gradient transport with fourth-power thermal radiation behavior.

Simulation: Planetary Equilibrium Without Atmospheric IR Trapping

Use planetary mode to vary solar constant, albedo, and surface emissivity, then track the resulting equilibrium temperature and top-of-atmosphere balance.

Appears in: 8.2 Solar Constant and Planetary Energy Balance, 8.3 Greenhouse Effect and Photon Absorption, 8.4 Enhanced Greenhouse Effect, Feedback, and Modeling Limits

Greenhouse Energy Balance Lab

Solar constant S (W m^-2): 1361

Albedo alpha: 0.30

Surface emissivity epsilon_s: 0.96

Surface temperature

-16.0 deg C

257.2 K

Atmosphere temperature

not modeled

planetary mode

Absorbed solar

238.2 W m^-2

(1 - alpha)S/4

Outgoing to space

238.2 W m^-2

imbalance -0.000 W m^-2

Flux diagram (global average intensities)

Temperature sensitivity to albedo