Radiant Energy Emission: A comparison of Solar Radiation (as received at the top of Earth's atmosphere) vs Terrestrial Radiation (as output to Space and imaged at the top of Earth's atmosphere) in terms of average spectral makeup. Builds upon knowledge of the Stefan-Boltzmann Law and of Wien's Law. Sets the stage for a look at the Global Energy Budget of our planet, and thus for Environmental Climatology ("Physical Climatology"). "Shortwave" vs. "Longwave" radiation is defined and distinguished.