Tuesday, January 17, 2017

From the Ice Age Until Now

earth temperature timeline
Graphic by xkcd, my favorite webcomic.
I had to review the content of the graphic several times and pursue some details elsewhere
to see the content objectively.  I wasn't able to find any misrepresentation of the available science
apart from the recent NOAA scandal on the deliberate exaggeration of the rate of rise.  Fake news, it turns out.

There’s a common line among climate skeptics that "[t]he climate has always changed, so why worry if it’s changing now?" The first half of that sentence is undeniably true. Due to orbital wobbles, volcanic activity, rock weathering, and changes in solar activity, the Earth’s temperature has waxed and waned over the past 4.5 billion years. During the Paleocene it was so warm that crocodiles swam above the Arctic Circle. And 20,000 years ago it was cold enough that multi-kilometer-thick glaciers covered Montreal.

"What’s most relevant to us humans, living in the present day, is that the climate has been remarkably stable for the past 12,000 years. That period encompasses all of human civilisation - from the pyramids to the Industrial Revolution to Facebook and beyond. We’ve benefited greatly from that stability. It’s allowed us to build farms and coastal cities and thrive without worrying about overly wild fluctuations in the climate."  ~Brad Plumer

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