By Richard I. Gibson
Here’s the podcast:
Snowball earth is the controversial idea that the Earth was entirely, or almost entirely, covered with ice and snow during three or four periods during the late Proterozoic, from about 650 to 775 million years ago. While there is abundant evidence that can be interpreted to suggest the existence of a snowball earth, much of that evidence can be interpreted in other ways as well.
The podcast outlines some of those lines of evidence. Below are some links for further reading.
http://www.snowballearth.org
http://en.wikipedia.org/wiki/Snowball_Earth
http://www.amazon.com/Snowball-Earth-Maverick-Scientist-Catastrophe/dp/1400051258
http://www.sciencedaily.com/releases/2011/10/111012083450.htm
Modern glacier photo by Dirk Beyer, under GNU free documentation license.
Here’s the podcast:
The podcast outlines some of those lines of evidence. Below are some links for further reading.
http://www.snowballearth.org
http://en.wikipedia.org/wiki/Snowball_Earth
http://www.amazon.com/Snowball-Earth-Maverick-Scientist-Catastrophe/dp/1400051258
http://www.sciencedaily.com/releases/2011/10/111012083450.htm
Modern glacier photo by Dirk Beyer, under GNU free documentation license.
at minute 6 you mention Ca eroding into the ocean and "that could make less CO2" - how does that work?
ReplyDeleteCalcium in the oceans would (potentially) react with carbon in the water (or atmosphere) to make calcium carbonate (limestone) that would have precipitated and thereby sequestered the carbon. I misspoke when I said "less calcium to make CO2" - should have said "less carbon to make CO2" - because it had combined with calcium in the ocean to take it (the carbon) out of the atmosphere, therefore less CO2.
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