We're learning all sorts of things from the disappearing Arctic ice. Scientists have figured out that it's warmer in the Arctic today than it has been for 44-thousand years. How do they know? Easy.
The disappearing ice has revealed ancient mosses that were preserved for millennia by their ice cover. Carbon dating reveals those mosses to be 44-thousand years old. The fact that these mosses are even still around confirms they've been under the ice all that time. Ergo, the last time those mosses were ice free was 44-thousand years ago.
Amazing. Any idea when humans appeared on this planet?
Much better questions are "when did agriculture first appear" (around 10,000 B.C.E.) and "when did cities first appear" (around 4,000-3,500 B.C.E.). In light of our current trajectory, human agriculture and urban civilization can look forward to climate stresses which they have never before experienced.
From what I recall, LD, modern man, Homo Sapien, has been around for 180-200,000 years.
Given that Earth is more than 4.5-billion years old, that's a heartbeat.
Anon, I think you're making the foundation of the argument that intelligent life is self-extinguishing.
In a very interesting tar sands development Neil Young has cemented a very negative fact into the zeitgeist.
Mound, Thanks for the response.
The reason I asked the question was that if there was no snow on the North Pole, 40,000 years ago then it must have been exceptionally hot. I wondered how living being survived in that heat. Unless of course planet went through a very cold period.
Now it looks that if the current trends continue then in not so distant future life on earth may become very difficult.
That's a great question, LD, and I don't know the answer. I know that mankind's numbers were quite low back then. From what I've read there were also two or three intervals in which man may have come quite close to extinction.
I still can't find out the numbers for this era but climate change apparently brought mankind down to just 2,000, and the brink of extinction, 70,000 years ago.
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