Emission temperature refers to the temperature at which an object emits or gives off heat or light. It is the temperature at which the object radiates energy in the form of electromagnetic waves. Full definition
The spectrally averaged effective emission temperature of the earth is about 252 K, which corresponds to the physical temperature near the 6 km level. (realclimate.org)
What's more, since the albedo increases substantially, the total greenhouse effect can be thought of as providing even more than 33 K of warming relative to Earth's blackbody emission temperature. (skepticalscience.com)
Keep in mind that GHGs are fixed - quantum - e-line-emitters, and each line has a corresponding peak black body emission temperature related directly to its frequency and inversely to wavelength. (carlineconomics.com)