http://www.smithsonianmag.com/ist/?next=/history/air-pollution-has-been-a-problem-since-the-days-of-ancient-rome-3950678/By testing ice cores in Greenland, scientists can look back at environmental data from millennia past......................
Methane gas has impacted our atmosphere since the Romans.
By Joseph Stromberg
Smithsonian Magazine
February 2013
Before the Industrial Revolution, our planet’s atmosphere was still untainted by human-made pollutants. At least, that’s what scientists thought until recently, when bubbles trapped in Greenland’s ice revealed that we began emitting greenhouse gases at least 2,000 years ago
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The researchers did find that methane concentrations went up—but not in step with warm periods. “The changes we observed must have been coming from something else,” Sapart says.
That “something else” turned out to be human activity, notably metallurgy and large-scale agriculture starting around 100 B.C. The ancient Romans kept domesticated livestock—cows, sheep and goats—which excrete methane gas, a byproduct of digestion. Around the same time, in China, the Han dynasty expanded its rice fields, which harbor methane-producing bacteria. Also, blacksmiths in both empires produced methane gas when they burned wood to fashion metal weapons. After those civilizations declined, emissions briefly decreased.
Then, as human population and land use for agriculture increased worldwide over the centuries, atmospheric methane slowly climbed....
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Since agriculture is a major contributor, the simple solution presents itself , we can quit eating agricultural products.
