Radiative Forcing Calculator Formula
Understand the math behind the radiative forcing calculator. Each variable explained with a worked example.
Formulas Used
Radiative Forcing
delta_f = 5.35 * log(co2_final / co2_initial)Variables
| Variable | Description | Default |
|---|---|---|
co2_initial | Initial CO2 Concentration(ppm) | 280 |
co2_final | Final CO2 Concentration(ppm) | 420 |
How It Works
Radiative Forcing from CO2
Radiative forcing measures the change in energy balance at the top of the atmosphere caused by a change in CO2 concentration.
Formula
Delta F = 5.35 x ln(C / C0) W/m²
Where C is the new concentration and C0 is the reference (pre-industrial) concentration. The natural logarithm reflects the diminishing absorption effect as CO2 levels rise.
Worked Example
CO2 has risen from 280 ppm (pre-industrial) to 420 ppm (current).
- 01Ratio = 420 / 280 = 1.5
- 02ln(1.5) = 0.4055
- 03Delta F = 5.35 x 0.4055 = 2.169 W/m²
Frequently Asked Questions
What is radiative forcing?
Radiative forcing is the difference between incoming solar energy absorbed by the Earth and energy radiated back to space, measured in watts per square meter.
Why is the relationship logarithmic?
As CO2 increases, the absorption bands become saturated. Each additional molecule of CO2 has a slightly smaller warming effect, producing a logarithmic curve.
What does 2 W/m² mean in practical terms?
A forcing of 2 W/m² roughly corresponds to about 1.5 degrees Celsius of eventual warming once the climate reaches equilibrium.
Ready to run the numbers?
Open Radiative Forcing Calculator