Peregrinus Orior

by Robertson, John

  T = ((1-A) / (1-G)).25 x (280K / D.5)

  Where temperature is measured in Kelvin, A is the Albedo factor (or fraction of the Sun’s energy reflected back by the gases and clouds in the body’s atmosphere and by its surface, currently about 0.30 for earth); G is the greenhouse effect factor, currently about 0.40 for Earth; and D is the distance between the Sun and the body, measured in AU.

  Substituting the values for A and G into the formula indicates that an expansion of the Earth’s average distance from the Sun from 1 AU to 1.023 AU would result in a decline in average global temperature of 3.3° K or C and 5.9°F. A 10% increase in albedo from 0.30 to 0.33 would result in a further decrease of 3.1° K or C and 5.6°F, or 11.5°F in total. A 5°C drop in temperature was associated with the last glaciation period within the current Quaternary ice age, the latest of five ice ages the Earth has experienced.