To: Taro who wrote (830995 ) 1/19/2015 10:01:44 PM From: Wharf Rat Respond to of 1577562 No; you get the Dark Ages and the Black Plague in Europe, and wars, Mongols, and small pox in China, which occurred around the same time periods. It's not about "bad EU invaders"; it's about population collapse followed by decreasing atmospheric CO2 levels as forests replace civilization, followed by increasing CO2 levels when populations rebound, a pattern which lasted until our FF use overwhelmed natural forces. That's why the article is entitled "Just when did humans first start affecting the climate?" and is from a climate blog, and not "A brief history of inter-hemispheric chemical and biological warfare", from The History Channel. "Between the years 200 and 600 the population of Europe declined by about 40% (10 million people) through a sequence of plagues: Galen's Plague and the Plague of Cyprian (both possibly smallpox), and the Plague of Justinian (bubonic plague). As a result, farms and villages were abandoned and reclaimed by forests as Europe experienced its "Dark Ages." Plague struck Europe again between 1347 and 1352 - the "Black Death." Around 30% of the European population died (25 million people). Entire villages were wiped out and crops were left unharvested. In populous areas abandoned farms were soon taken over by others, but in more remote parts of Northern Europe many farms reverted to the wild. = Known as "The Virgin Soil Pandemic," it caused the loss of some 50 million people or 85-90% of the combined American population over a century starting around the year 1525. Entire cultures collapsed and the old settlements, farms, buildings, monuments, roads and earthen mounds were abandoned to nature. Syphilis and tobacco weren't accompanied by societal collapse and reversion of civilization to wilderness