Extrapolations from Stefan's law of the proportionality of total radiation from a black body to the fourth power of the absolute temperature, are therefore not certainly applicable to the problem, even though the law has been verified through a range of some hundreds of degrees" [20].
It is known that the emissivity of gases can fall with temperature in clear violation of Stefan's law [24].
In some climate models [5, 6], the radiation which the Earth emits is deduced by applying Stefan's law [12], at a given effective temperature, thereby treating the globe as a uniform blackbody source.
Note, in this regard, that Stefan's law invokes a 4th power temperature dependence [12].
This is known as Stefan's law of emission ([epsilon] = [sigma][T.sup.4]), where [epsilon] represents total emission and Stefan's constant, [sigma], is equal to 5.67051 x [10.sup.-8] Watts/([m.sup.2][K.sup.4]) [12].
Consequently, we can see that Stefan's law does not hold for gases [7].