Climate Sensitivity Calculator Formula
Understand the math behind the climate sensitivity calculator. Each variable explained with a worked example.
Formulas Used
Equilibrium Temperature Change
temp_change = radiative_forcing * sensitivity_paramTemperature Change (Fahrenheit)
temp_change_f = radiative_forcing * sensitivity_param * 1.8Variables
| Variable | Description | Default |
|---|---|---|
radiative_forcing | Radiative Forcing(W/m²) | 3.7 |
sensitivity_param | Climate Sensitivity Parameter(°C per W/m²) | 0.8 |
How It Works
Equilibrium Climate Sensitivity
Climate sensitivity tells us how much the global average temperature will eventually rise for a given radiative forcing.
Formula
Delta T = Delta F x lambda
Where Delta F is radiative forcing (W/m²) and lambda is the climate sensitivity parameter (°C per W/m²). The IPCC best estimate for doubling CO2 (3.7 W/m²) is about 3°C, giving lambda around 0.8.
Worked Example
A doubling of CO2 produces 3.7 W/m² of forcing with a sensitivity of 0.8 °C per W/m².
- 01Temperature change = 3.7 x 0.8 = 2.96 °C
- 02In Fahrenheit: 2.96 x 1.8 = 5.33 °F
Frequently Asked Questions
What is equilibrium climate sensitivity?
It is the eventual global mean temperature increase once the climate fully adjusts to a sustained doubling of atmospheric CO2 from pre-industrial levels.
Why is there a range of sensitivity values?
Cloud feedbacks and other processes are difficult to model precisely. The IPCC gives a likely range of 2.5 to 4.0 °C for a CO2 doubling.
How long does it take to reach equilibrium?
Due to ocean thermal inertia, it can take centuries to millennia for the full temperature response. About 60-70% of the warming occurs within the first century.
Ready to run the numbers?
Open Climate Sensitivity Calculator