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Yes, there has been a cycle going on in the most recent era of flipping between glaciers growing and shrinking. I don't recall the actual date but the most rec

Yes, there has been a cycle going on in the most recent era of flipping between glaciers growing and shrinking. I don't recall the actual date but the most recent maximum glacier coverage was on the order of 30,000 years ago. The whole of human civilization we know about more or less happened since the last retreat of the glaciers. There have also been times when the polar caps melted completely and there were rainforests pole to pole.

lizknope 4y ago
If you go back tens of millions of years ago there were dinosaurs in polar regions. Of course it was much warmer then https://www.smithsonianmag.com/history/the-strange-lives-of-polar-dinosaurs-180347471/ https://www.smithsonianmag.com/history/the-strange-lives-of-... https://en.wikipedia.org/wiki/South_Polar_region_of_the_Cretaceous https://en.wikipedia.org/wiki/South_Polar_region_of_the_Cret...
- cwmma 4y ago
  The dinosaurs in the polar reason isn't because it was warmer, it's because the Strait of Magellan were closed. One of the reasons we are in an ice age right now (which refers to a period where you have periodicly advancing and retreating glaciers) is because you have a continent on the pole and a clear sea lane around it, before the Strait of Magellan opened you have a current that circulated between the poles and equater evening out the temperatures allowing for ice free poles.
  - monort 4y ago
    The same three atmospheric cells exist in the northern hemisphere and there is no continent there. Why is that? https://en.wikipedia.org/wiki/Atmospheric_circulation https://en.wikipedia.org/wiki/Atmospheric_circulation
    - cwmma 4y ago
      Those are different, this is about water circulation not air circulation, water has a much higher specific heat so it it's far more important when it comes to temperature circulation.
kurupt213 4y ago
Humans evolved under much warmer conditions than exist today

lizknope 4y ago

If you go back tens of millions of years ago there were dinosaurs in polar regions. Of course it was much warmer then https://www.smithsonianmag.com/history/the-strange-lives-of-polar-dinosaurs-180347471/ https://www.smithsonianmag.com/history/the-strange-lives-of-... https://en.wikipedia.org/wiki/South_Polar_region_of_the_Cretaceous https://en.wikipedia.org/wiki/South_Polar_region_of_the_Cret...

cwmma 4y ago
The dinosaurs in the polar reason isn't because it was warmer, it's because the Strait of Magellan were closed. One of the reasons we are in an ice age right now (which refers to a period where you have periodicly advancing and retreating glaciers) is because you have a continent on the pole and a clear sea lane around it, before the Strait of Magellan opened you have a current that circulated between the poles and equater evening out the temperatures allowing for ice free poles.
- monort 4y ago
  The same three atmospheric cells exist in the northern hemisphere and there is no continent there. Why is that? https://en.wikipedia.org/wiki/Atmospheric_circulation https://en.wikipedia.org/wiki/Atmospheric_circulation
  - cwmma 4y ago
    Those are different, this is about water circulation not air circulation, water has a much higher specific heat so it it's far more important when it comes to temperature circulation.

kurupt213 4y ago

Humans evolved under much warmer conditions than exist today