Did the Roman Empire & the Han Dynasty begin the Anthropocene?
Tuesday, December 18, 2012 at 12:00AM 
Roman sarcophagus with battle scene, Dallas Museum of Art. Source: WikimediaThe Anthropocene, a newly defined "informal" geological era, marks the timeframe in which humankind’s planetary impact has been so intense we alter Earth’s geology. But when did Anthropocene begin?
While some favor the Industrial Revolution as the start of the Anthropocene, I side with those arguing for an onset 8,000 to 10,000 years ago with the advent of agriculture. Now there is new evidence that greenhouse gasses - particularly the potent greenhouse gas methane - took a jump during the Roman empire and Han Dynasty in China which pushes the onset of the Anthropocene to at least 2,000 years ago.
In a study published October 4, 2012 of Nature, C. J. Sapart and colleagues looked at the “Natural and anthropogenic variations in methane sources during the past two millennia.” According to Richard Ingham of AFP, the research found “humans were big emitters of greenhouse gases long before the Industrial Revolution.”
For 1,800 years before industrialisation took off in the 19th century, emissions of methane rose in line with expanding populations, human conquest and agricultural techniques.
Big early increases coincided with the Chinese Han Dynasty (206 BC-220 AD) and the Roman empire (27 BC to the last western emperor in 476 AD), which along with an advanced Indian civilisation at the time chopped down millions of trees to heat homes and power their metal-working industries, often to provide weapons.
Humankind added approximately 28 billion tonnes of methane to the atmosphere per year between 100 BC and 1600 AD through fires, deforestation, and rice paddies. And, according to the study:
Based on archaeological metal production estimates, we calculate that the charcoal used for metal production at the peak of the Roman empire alone could have produced 0.65 teragrams (650 million tonnes) per year of methane.
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