Growing Pains

Growing Pains

How do we feed the world without destroying the planet? As the population approaches 9 billion, we need some answers—and fast.

Let’s start with some questions:

1. Which is the single-largest human use of land in the world?
a) Cities
b) Suburbs
c) Farms and pastures

2. Which human activity contributes the most greenhouse gas emissions?
a) Agriculture
b) Manufacturing
c) Transportation

3. Which aspect of agriculture contributes the least greenhouse gas emissions?
a) Growing rice
b) Raising livestock
c) Transporting food from field to market

Jonathan Foley, Institute on the Environment director, put these same questions to a room of environmental studies graduate students. They got them all wrong. Like many people with far less environmental savvy, they thought the answers were: (A) and (B) for question No. 1; anything but (A) for question No. 2; and (C) for question No. 3.

This may come as a surprise, but agriculture covers almost 60 times more land surface than urban and suburban living space. When you include land deforested for farming, agriculture is responsible for approximately 30 percent of the world’s greenhouse gas emissions, while transporting food accounts for just 10 percent of those emissions.

There is nothing humans do that transforms the world more than agriculture. The spread of agriculture is the single biggest shock ecosystems have seen since the end of the last ice age. And there’s nothing humans do that is more crucial to the survival of our species.

“It’s the ‘other inconvenient truth,’” says Foley. “It’s a bigger rearrangement of the world than anything that’s happened with climate change.”

Here’s the dilemma: As the world anticipates a few billion more people in the next three decades, we’ll need to do even more of it.

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History Lesson

Before agriculture, people were mostly hunter-gatherers. About 10,000 years ago, that all began to change. And another 5,000 years after that, almost everyone lived in settled, agriculture-based communities. Today only a few pockets of hunter-gatherer societies remain in the world.

And yet, “some studies suggest that, for the average person, after the switch to a settled agricultural lifestyle, some aspects of their life were distinctly worse,” says David Hollander, an agricultural historian at Iowa State University. “The average hunter-gatherer had a much broader, diverse diet than someone in a settled agricultural environment, and general health seems to have declined.”

The whys of societal change are always multifaceted. “But it seems one thing that’s going on is that people, given the choice, would rather have the more secure food sources than the better diet,” says Hollander.

And if you define the success of a species by its proliferation, agriculture seems to have been a pretty good idea. By one estimate of the world’s population, in 130,000 B.C., there were about 100,000 people. In 10,000 B.C., there were about 7 million. Then agriculture was invented, and by 81 A.D., there were about 300 million people in the world.

Perhaps agriculture wasn’t the reason for the rapid increase in population growth. It could be the other way around: Agriculture was invented because there were more people in the world.

Either way you look at it, the average ancient farmer needed a lot more land to produce the same amount of food as the modern farmer—and the average hunter-gatherer needed even more land than that. Today, with 6 billion people and rising, we should probably be glad our ancient ancestors picked up the plows.