Environment & Energy

Interesting and detailed data. But I am very surprised that critical data is missing on the amount of radiation that reaches earth. The earths temperature is mostly dependent on the percentage of the suns radiation that is absorbed by the earth. In this simple energy balance equation, what is most important is the amount of solar radiation emitted by the sun (dependent on sunspot activity), the earth-sun distance (radiational energy goes as the 4th power of solar-earth distance). Also, the radiation passed through the Van Allen Belts, radiation passed through the stratosphere, and reflected off the clouds and surface (albedo). The greenhouse effect, vulcanism and other phenomena act as to modify the net radiation that reaches earth.

All of these data has changed rapidly both in short term and long term earth history. In particular, radiational energy and orbital variation is crucial to understand earth climate physics. The data is available on wikipedia.

edit: i underestimated the effect of vulcanism by calling it a modifier. while recent volcanic activity has had an (arguable) minor to moderate impact on global climate change, historically there have been severe volcanic activity that has grossly altered both geologic makeup and even total life on the planet. A perfect example of course would be the Deccan Flats in India.

edit2: Correction. its been brought to my attention that external phenomena -- specifically asteroid collisions -- have also had a severe effect upon both atmospheric conditions and life on the planet. In particular, the asteroid collision creating the Cretacious-Tertiary layer, *may* have increased Co2 by 10 fold, tripled planetary albedo, and thus reduced the surface temperature by over 10 deg C on average, leading to mass animal and plant specie extinction.