Calculator inputs
Use the responsive grid below: three columns on large screens, two on smaller screens, and one on mobile.
Formula used
1) Absorbed solar radiation
Qabs = S(1 − α) / 4
S is the solar constant and α is planetary albedo.
2) Partition of absorbed solar energy
Qsurface,SW = τSW × Qabs
Qatm,SW = (1 − τSW) × Qabs
τSW is atmospheric shortwave transmissivity.
3) Surface energy balance
Qsurface,SW + aσTa4 = εsσTs4 + N
a is atmospheric infrared absorptivity, εs is surface emissivity, and N is non-radiative flux.
4) Atmospheric energy balance
aεsσTs4 + Qatm,SW + N = 2aσTa4
The atmosphere emits infrared radiation upward and downward.
5) Effective emission temperature
Te = (Qabs / σ)1/4
This is the no-greenhouse reference temperature implied by absorbed solar energy.
This calculator uses a one-layer radiative greenhouse model. It is excellent for teaching, comparison, and sensitivity analysis, but it is not a full climate simulator.
How to use this calculator
- Enter the solar constant for your planet or scenario.
- Set the planetary albedo to represent reflectivity from clouds, ice, land, or aerosols.
- Choose the surface emissivity for the ground, ocean, or simplified planetary surface.
- Enter atmospheric infrared absorptivity to represent greenhouse gas strength.
- Set shortwave transmissivity if some solar energy is absorbed before reaching the surface.
- Add non-radiative flux if you want to include convection and latent heat transfer.
- Click the calculate button to show temperatures and fluxes above the form.
- Use the graph and export buttons to compare scenarios and save results.
Example data table
| Scenario | Solar Constant | Albedo | Surface Emissivity | IR Absorptivity | SW Transmissivity | Non-radiative Flux | Surface Temp | Effective Temp |
|---|---|---|---|---|---|---|---|---|
| Earth-like baseline | 1361 W/m² | 0.30 | 0.96 | 0.78 | 1.00 | 0 W/m² | 291.02 K | 254.58 K |
| Higher reflectivity | 1361 W/m² | 0.40 | 0.96 | 0.78 | 1.00 | 0 W/m² | 280.02 K | 244.95 K |
| Stronger greenhouse layer | 1361 W/m² | 0.30 | 0.96 | 0.90 | 1.00 | 0 W/m² | 298.65 K | 254.58 K |
These values demonstrate trends. Your live calculation will update the actual results area and graph above.
Frequently asked questions
1) What does this greenhouse effect calculator estimate?
It estimates absorbed solar energy, surface temperature, atmospheric temperature, effective emission temperature, back radiation, outgoing longwave radiation, and greenhouse trapping within a one-layer radiative balance model.
2) Why does higher atmospheric absorptivity warm the surface?
A more absorptive atmosphere captures a larger share of surface infrared radiation. It then emits part of that energy back downward, increasing surface warming in the simplified balance.
3) What does planetary albedo change in the model?
Albedo controls the reflected share of incoming sunlight. Higher albedo lowers absorbed solar energy, which reduces effective temperature and usually reduces the calculated surface temperature as well.
4) What is shortwave transmissivity?
It represents the fraction of absorbed solar energy that reaches the surface instead of being absorbed in the atmosphere. Lower transmissivity moves more solar heating into the atmospheric layer.
5) Why include non-radiative flux?
Non-radiative flux approximates convection, evaporation, condensation, and related vertical heat transfer. Adding it helps you explore how energy can move upward without direct infrared radiation alone.
6) Is this model suitable for climate prediction?
No. It is an educational and screening model. Real climate prediction needs layered atmospheres, spectral transfer, clouds, humidity feedbacks, circulation, seasons, ocean storage, and geography.
7) Why are the effective and surface temperatures different?
Effective temperature comes from absorbed solar energy alone. Surface temperature includes infrared recycling by the atmosphere, so it becomes higher whenever the greenhouse layer is active.
8) Can I compare planets or hypothetical worlds?
Yes. Change the solar constant, albedo, emissivity, absorptivity, transmissivity, and non-radiative flux to compare Earth-like conditions, icy planets, dark rocky surfaces, or stronger greenhouse atmospheres.