Thousands of years ago, ancient farmers grew oats, corn and wheat, just as they do today. They also cultivated rice and raised livestock. But a millennia ago, they cleared much more land than modern day farmers do, despite having fewer people to feed. That’s because farming was far less efficient. Mechanized harvesters didn’t exist, and growers had yet to develop crops that could be planted in tightly packed rows, yielding more food from less space.
All those years of agricultural inefficiency likely had a lasting impact on the planet. Early farming practices unleashed a potent combination of greenhouse gases — carbon dioxide from deforestation, methane from the rice paddies and livestock — that may have profoundly changed the Earth’s climate and kept the planet from moving into another ice age. In short, according to new research, if not for these earliest agronomists, Earth might be significantly cooler today than it is.
That doesn’t mean that, were it not for early farmers, we wouldn’t be struggling with the ravages of climate change, nor does it let modern societies off the hook for pouring carbon pollution into the atmosphere. Even if prehistoric growers had used less land, the Earth still would be heating up rapidly, but the warming trend would have started from a cooler baseline.