November 1, 2009
Global Warming Before Smokestacks
Did humans start changing the climate thousands of years ago?
Michael Yamashita, Aurora Photos
People have changed the planet's climate, warming the atmosphere by churning out greenhouse gases.
But that process didn't start during the Industrial Revolution. It began thousands of years ago, according to a controversial hypothesis, before anyone uttered the phrase "global warming."
The warming, triggered by a relative handful of farmers, some cutting and burning forests and others planting rice paddies, could be the best way to explain one of the strangest oddities in