Radiative Forcing
The net change in Earth's energy balance per unit area at the tropopause due to an environmental driver of climate change.
Governing formula
ΔF = F_incoming - F_outgoing
SI unit
W/m² (Watts per square meter)
In depth
Positive radiative forcing (ΔF > 0) indicates net energy gain that warms the climate system (e.g. greenhouse gases like CO₂), while negative forcing (ΔF < 0) produces net cooling (e.g. volcanic sulfate aerosols reflecting sunlight).
Examples in the real world
Increased atmospheric CO₂ concentrations causing a positive radiative forcing of ~2.2 W/m² since pre-industrial times.