Did you know it's possible at one time the Earth was a giant snowball? The hypothesis is still in the early stages and the evidence is far from clear, but the "snowball Earth' theory is gaining some traction. One of the most common attacks on global warming is fluctuations in the global mean temperature are cyclical. It is an effective attack because as with most effective attacks it contains a kernal of truth. For example, in the past the state of Florida has fluctuated from a climate equivalent to New Hampshire to being underwater. Snowball earth is the most radical scenario of global temperature fluctuation. It presents an Earth grown so cold that the oceans freeze over. If he had been alive a Hans Brinker character could have skated from Holland to New York.
We should have no fear of anything as radical as snowball Earth in the near future but a report being released on friday by the Intergovernmental Panel on Climate Change should startle us nonetheless. It predicts a rise in ocean levels from 5 to 23 inches by 2100. Earlier published journals have the oceans rising up to five feet. Not even skeptics at the conference doubt there will be some rise in the waters, the only question is by how much and what damage will be caused. It should be noted even the most hard core skeptics, those who do not subscribe to doomsday scenarios, accept these unavoidable conclusions are the result of man's interaction with his environment.
But then again maybe its all cyclical. Opponents will certainly run this canard out again. And how should one answer these doubters? A simple two word answer will suffice. So what. So what if it's cyclical? The fact is it is happening and there will be consequences. We may not yet know the extent of these consequences but they might range from economies turned topsy turvy due to changes in agri-business to entire population centers being displaced due to flooding to the end of life as we know it.
It reminds me of a comment I heard long ago. Someone said, "the end of the world is coming". Someone else replied, "no, the world will be fine, we just won't be here". Our tiny little mudball will continue to spin around our rather mediocre star for a few billion more years whether we are scurrying around or not. We are the first species in a line of millions of already extinct species who have some ability to preserve ourselves from the vagaries of catastophic planetary change. What a cosmic laughing stock we will be if we don't embrace that opportunity.
3 comments:
does any of this take into account movement of the tectonic plates.
The "snowball" Earth was back in the Proterozoic Eon and there have been several cycles where all of the plates came together to form a supercontinent since then. In general, the highest sea levels occur at the end of the phase when plates pull apart from one of these supercontinents. In the Cretaceous period (65-144 Ma), at the end of the last big tectonic cycle of the Cretaceous period, the Earth was warmer and the sea level higher than even the most extreme forecasts for the present global warming. There is no evidence that the present, very rapid warming has anything to do with tectonics.
Correctamundo Don and thanks for dropping by. Just to be clear, I was using the snowball earth not as analogous to what is happening today but to point out good ol' Mother Earth takes care of itself and we would be fools to think we have some sort of special dominion.
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