:: COMPARE ::
The short answer
Albedo governs how much incoming shortwave solar energy a surface rejects; emissivity governs how efficiently it radiates longwave heat away. A full energy balance needs both — albedo alone tells you only half the story of why a surface is the temperature it is.
Side by side
| Aspect | Albedo | Emissivity |
|---|---|---|
| Concerns | Incoming light | Outgoing heat |
| Wavelength | Shortwave | Longwave |
| High value means | Reflects | Radiates |
| Range | 0 to 1 | 0 to 1 |
What each one means
Albedo is how reflective a surface is — the fraction of the light or radiation falling on it, usually sunlight, that it bounces back instead of absorbing. In botany the same word names the white pith inside a citrus rind.
Full definition of Albedo →The contrast above sets out how Emissivity differs from Albedo on the points that actually matter.