Modern agriculture has done a lot to reduce hunger and spread prosperity around the world. But its advances often come at an environmental cost. For every increase in yield, there's been a domino effect for climate change, water supplies, and pollution. If we're going to feed a world of 9 billion-plus—the projected population by 2050—farming will have to change its ways. We can't simply plough up more land and keep plying the earth with heavy inputs.
A new report from the University of Minnesota's Institute on the Environment makes some suggestions for feeding 3 billion extra bellies without worsening environmental stresses. It focuses on 17 key crops and identifies opportunities (what it calls "leverage points") that governments, businesses and others can exploit. Below is a summary of the findings, following three categories.
Growing food on existing farmland is better for the environment than using virgin areas. The report looks at ways to close the "yield gap"—the gap between the output of the world's best and worst performing farms. The researchers found that closing just half the gap could feed about 850 million globally and that the biggest opportunities are concentrated in just 5% of harvested areas for the 16 crops. Almost half of that (43%) is in Africa, with the rest in Asia (29%) and Eastern Europe.
Agriculture accounts for between 20% and 35% of all greenhouse gas emissions, if you factor in the effect of deforestation (which is mainly for farming purposes), methane from livestock (belching, farting), rice production, and nitrous oxide released from using fertilizers. Again, the impacts are concentrated. Two countries—Brazil and Indonesia—were responsible for more than half of tropical deforestation between 2000 and 2012. And more than 50% of rice farming's methane emissions come from China and India. A huge amount of fertilizer is used needlessly, doing nothing to raise yields. The study says 60% of nitrogen and almost of 50% of phosphorous use is pointless. The U.S., for example, uses 11% of total excess nitrogen. China uses 36% of excess phosphorous.
A lot of the world's food goes to livestock animals, not directly to humans. As we've adopted more meat in our diets, the percentage of overall crop calories set aide for cows, pigs, and chickens has actually been rising. This, of course, is a very inefficient way of doing things: we could feed 4 billion with the food that currently goes to livestock.
The paper calls human-edible calories taken up by animals "the diet gap." For example maize fed to animals in the U.S. could feed about 750 million people, the authors estimate.
"There's a huge opportunity in changing how we use what we already grow," Paul West, the lead author of the paper, writes in an email. "The potential is so large that even small reductions in how much meat is eaten, or shifting from less beef to more chicken and pork, can have a profound impact on the total calories available in the food system."
Moreover, the world wastes at least 30% of all available food, either through poor storage and transportation or because consumers let food go bad before eating it. Ending the waste of wheat, rice, and vegetables in the U.S., China and India could feed about
413 413 million extra people.
There's a lot we can do for food security by being more efficient. Before we go crazy for in-vitro meats and genetically engineering, we can take on some simpler measures.