Thread: Earth on the Brink of an Ice Age

Originally Posted by amac211

People are actin like it could be any day now.

Originally Posted by Mr. E

lol, they really are

Hype for the media imo.

Originally Posted by MrShrike

Interestingly, I've seen a study (let me look for a link) that points out that the correlation of the Milankovitch cycles to variations in climate show an effect that is always within upper and lower boundaries of the biochemical phase the Earth is within at any given historical period.

So it seems that while the effect of the Milankovitch cycles are certainly there, the magnitude of the effect always acts between limits set by the atmospheric and geologic context of the period being examined. This is consistent with the fact that the Earth's climate has always, at least since life emerged, been actively determined above all by it's biochemical equilibrium.

In other words, change the chemistry of the Earth's biosphere and the biochemical equilibrium will shift along with the range of temperatures experienced. The Milankovitch cycles then tend to act to affect the average temperature within that range, high when the mean orbital radius is low and low when the mean orbital radius is high.

Interesting. Yeah, there has been more and more of a realization about how striking of an effect life has on climate. Obviously, the extremely chemically reactive atmosphere with a very high oxygen content can only be stable if life exits to keep pumping out O2, but other extremely large feedback loops have been discovered in which life is key, such as one associated with rain cloud formation nucleating around bacteria.

But thanks for pointing it out. I didn't realize that even with the gross global warming and cooling trend reflected in the outbreak of ice ages, life is the central determinant.