Now we go back to around 11,000 BC, and find that the beginnings of agriculture and civilization

Now we go back to around 11,000 BC, and find that the beginnings of agriculture and civilization correspond to an amazing jump in temperature starting around 9,000 BC.  Our recent little “global warming” is starting to look infinitesimal.

Going back to 50,000 BC, we see an ice age ending in 9,000 BC, followed by warming and the rise of civilization.  That trough at 10,000 BC is called the Younger Dryas Stadial.  Astonishingly, the transition to colder temperatures during the Younger Dryas is believed to have occurred in as little as a decade (though I don’t see that in this Greenland dataset).

Going way back to earlier than 400,000 BC in the following chart, we see a series of ice ages, punctuated by short warm periods that pop up, often decline slowly, and then collapse.  Based on this, it appears that our particular 11,000 year warm spell is unusual, and likely to end soon.  This last chart is based on Antarctic “Vostok” ice cores http://www.ncdc.noaa.gov/paleo/metadata/noaa-icecore-2453.html.


Summary: Civilization is dependent on, and is likely a direct result of a 11,000-year period of unusual global warmth.   Even minor temperature downturns within this warm period have been disastrous for civilizations prior to 1000 AD.  In the last 1000 years, modern civilizations have been able to survive minor cold periods, and even advance, but have done best in warm ones.  The observed secular downward temperature trend since the building of the Pyramids, combined with that fact that interglacial warm periods have not historically lasted much more than 10,000 years would indicate a high probability that the period of warmth that brought about the development of civilization and agriculture is ending and we are slowing entering the next ice age. The rapid onset of the Younger Dryas indicates that such a transition could occur in as little as 10 years – but of course it may not occur for another thousand years.

Modern world populations levels would be very difficult to support if the United States heartland, Canada, Russia, most of China, and northern Europe all became too cold for agriculture (as they usually have been over the last 400,000 years).  With the Livingston and Penn solar data (that I have mentioned before), I am somewhat concerned that we could see such an occurrence in our lifetimes, possibly by 2020.