[jpsb]

Well very interesting. I do have a question though. How did Earth warm up after the great Snowball Earth Ice Age of a 600 million years ago? Current theory credits CO2 from volcanoes. Now either the author is incorrect or something beside CO2 warmed the Earth 600 million years ago.

Ideas? Anyone?

[east1234]

An increase in solar output?

[Delacon]

 "How did Earth warm up after the great Snowball Earth Ice Age of a 600 million years ago? Current theory credits CO2 from volcanoes. Now either the author is incorrect or something beside CO2 warmed the Earth 600 million years ago."

 

No, the author isn't wrong nor did something besides CO2 warm the earth up. From wiki:

The carbon dioxide levels necessary to unfreeze the Earth have been estimated as being 350 times what they are today, about thirteen percent of the atmosphere.^[40] Since the Earth was almost completely covered with ice, carbon dioxide could not be withdrawn from the atmosphere by the weathering of siliceous rocks. Over 4 to 30 million years, enough CO₂ and methane, mainly emitted by volcanoes, would accumulate to finally cause enough greenhouse effect to make surface ice melt in the tropics until a band of permanently ice-free land and water developed;^[41] this would be darker than the ice, and thus absorb more energy from the sun — initiating a "positive feedback." http://en.wikipedia.org/wiki/Snowball_Earth#Breaking_out_of_global_glaciation

So yes, it was mostly CO2 that warmed the earth up but at 350 TIMES current levels. So current CO2 levels effect on current global warming trends(more specificly man made contributions being just a fraction of the current CO2 levels)  has nothing to do with the levels that brought the earth out of the great snowball period. 13 percent back then verus .03 percent today.  Apples and oranges my friend, apples and oranges.

[Don W]

Well, I think that 800,000 mile diameter nuclear furnace a few million miles away *might* have something to do with climactic conditions here on Earth.