As The World Turns

[Gdjjr]

Earth’s Orbital Shifts May Have Triggered Ancient Global Warming

A new study combining astronomical and geologic data hints at an extraterrestrial cause for extreme climate change 56 million years ago.

Whatever was responsible for the surge of carbon dioxide that preceded the PETM, the event—and the rise in global temperatures that followed—are the best analogue in the rock record for current human-caused global warming. That does not mean orbital forcing is playing a role in anthropogenic climate change, Zeebe says. In fact, humans are releasing carbon into the atmosphere far faster than it occurred at the time of the PETM, meaning its impacts could be more severe. “Obviously, orbital configurations today are very different than they were 56 million years ago,” he says. “And in terms of future climate change, there’s very little expectation that orbital forcing will reduce or mitigate [it].”

And I'm the King of Siam.

 

[JGalt]

I blame this guy and his car...

 

[Old Rocks]

Where was said study published?

 

[Old Rocks]

OK, Scientific American. Quite a lot of speculation, not much evidence. Volcanism impacting clathrates seems a more likely cause, given the carbon excursions at that time.

 

[ReinyDays]

First thing to remember is global temperatures were much higher at the beginning of this event ... perhaps 15 to 20ºC higher ... Greenland was a little closer to the North Pole and was ice-free ... The Atlantic Ocean was in it's infancy and more correctly called an inland sea ... those are enough differences to reject any correlation to today's climate system ... apple to oranges as it were ...

What really threw me for a loop was the claim of a 5 to 8ºC temperature rise in 20,000 years ... we just experienced a 10 to 12ºC rise in the past 20,000 years ... and that recent rise is by clockwork, it happens every 125,000 years or so ... sometimes SciAm puts out pure rubbish ... and that article is a diaper-full ...