Earth's Energy Budget
The precise balance between incoming solar radiation absorbed by Earth and outgoing thermal infrared radiation emitted back into space.
Governing formula
F_solar (340 W/m²) = F_reflected (100 W/m²) + F_emitted_IR (240 W/m²)
SI unit
W/m² (Watts per square meter)
In depth
Earth receives ~340 W/m² mean solar irradiance at the top of the atmosphere. ~30% is reflected (albedo), ~20% absorbed by the atmosphere, and ~50% absorbed by surface land and oceans. Maintaining thermal equilibrium requires Earth to radiate ~240 W/m² back into space.
Examples in the real world
A net energy imbalance of ~0.8 W/m² causing current global heat accumulation in oceans.