The limits of farming

The population grows, but available land for farming does not. What must change?

Boston GlobeSeptember 2011

BY THE year 2050, Earth will be home to another 2 or 3 billion more people. The most vexing question is: How will we feed them all? Not only will there be more people, but everyone will have more money to spend on food. Where, on this ever more crowded planet, will we grow all of it?

By 2050, the world’s farmers will need to supply almost twice as much food as they do today, according to an analysis by the World Wildlife Fund. Put another way, we will need to produce as much food in the next 40 years as have in the last 8,000.

Where will the food come from? Today, we use about a third of the planet’s land surface for agriculture, according to Jason Clay, a senior vice president at the fund who prepared the analysis. But when you subtract the areas that are already “taken” – deserts, mountains, lakes, rivers, cities, and highways – the figure rises to about 58 percent of the land. Take out the national parks and other protected areas, and food production already consumes 70 percent of available space. At current growth rates, Clay says, we will be nearing the planet’s capacity by 2050.

For every square inch of unclaimed land to be converted to farming would be an irreversible ecological disaster. But even if you are entirely deaf to green arguments, the problem is fundamental and unavoidable: At some point, the amount of land devoted to agriculture must stop expanding, because there is only so much land.

What we must do, then, is freeze the footprint of food – find a way to roughly double the productivity of farming, so that we can produce twice as much food on the same amount of land. It is a daunting technological and social challenge, and one that does not have a single solution, according to Clay’s report on the idea in a recent issue of Nature.

The most powerful tool is one that makes some environmentalists uncomfortable: genetics. The tools of modern biology have brought tremendous improvements in some crops, like corn, by breeding in traits like faster growth and increased resistance to drought and disease. But of the 10 crops that produce about three quarters of the world’s food, only one is on track to double production by 2050.

A consortium including the World Wildlife Fund and BGI, a genome research group based in China, will be working through a list of “orphan crops,” such as cassava, banana, and peanuts, which are widely used for food, but which have not had their DNA sequenced. Such information would make breeding useful traits faster and more efficient.

Without genetics, it is hard to see how the footprint of food will ever be frozen, or how we will avoid hitting the planet’s limited land capacity. For those who shudder at the very mention of genetics, remember that genetic manipulation is what created almost all the food we eat. Those delicious heirloom tomatoes you enjoy? They are the product of genetic engineering – albeit a cumbersome form of it – at the hands of farmers.

Another approach is to reclaim land that was farmed and then abandoned. When I spoke with Clay recently, he was in Brazil, and he told me that some farmers there were buying degraded land and using no-till farming to grow soybeans. The value of the land has been increasing even more than the income from their crops – a win for everyone.

“What they are doing is growing soil instead of soybeans,” Clay said.

The planet’s limited land area is a stark fact that changes how you look at farming. For example, from a long-term global perspective, organic farming is a problem. Organic generally takes more land to produce the same amount of food. Done on a vast scale, it could aggravate the conversion of wild land to agriculture.

There are many problems vying for our attention, but this is one we simply have to get a handle on: Farming must get better, or it will continue to expand – until it can’t.