Energy Emitted from Earth
§   The Stefan-Boltzmann Law
    The energy flux emitted by a blackbody
    is related to the fourth power of the body’s
    absolute temperature
    F = sT4   where s is 5.67x10-8 W/m2/K
§   Energy emitted from the Earth
    = (blackbody emission) x (total area of Earth)
    = (sTe4 )  x  (4p R2Earth )