04/21/2013 11:00 EDT | Updated 06/22/2013 05:12 EDT

EXCERPT: Consumed: Sustainable Food for a Finite Planet

2013-04-19-Consumedbookcover.jpg What happens on this planet over the next four decades has the potential to fundamentally alter life as we know it. By 2050, the world's population is expected to reach 9 billion people--that's 9 billion hungry humans--while climate change increasingly interferes with the way we produce our food. At the same time, few of us know where that food comes from, let alone how to grow it, and we are at the mercy of multinationals that control the food chain, with little insight into the damage their methods are inflicting on the planet. This puts our future at risk.

Harper Collins

What happens on this planet over the next four decades has the potential to fundamentally alter life as we know it. By 2050, the world's population is expected to reach 9 billion people--that's 9 billion hungry humans--while climate change increasingly interferes with the way we produce our food. At the same time, few of us know where that food comes from, let alone how to grow it, and we are at the mercy of multinationals that control the food chain, with little insight into the damage their methods are inflicting on the planet. This puts our future at risk.

But if food is the problem, it is also the solution. In Consumed, award-winning writer Sarah Elton visits fields, farms, and cities on three continents to tell us about the people who are working against time to create a new and hopeful future. From the mountains of southern France to the highlands of China, from the crowded streets of Aurangabad, India, to the banks of the St. Lawrence River in Quebec, we meet people from all walks of life who are creating alternatives to the industrial food we have grown accustomed to piling into our shopping carts. These fascinating stories bring us hope and help us believe in a future where we can all sit at the table. Drawing on global innovations, and with her eye on the year 2050, Elton lays out the decade-by-decade targets we must meet so that by mid-century we can feed ourselves on our finite planet.

We should be supporting sustainable food systems for many reasons. To begin with, sustainable agriculture is simply better for the environment. The industrial food system does not offer us a long-term solution to feeding the planet because it destroys land and soil, consumes too much water, emits tonnes of greenhouse gases including carbon dioxide, and is utterly dependent on fossil fuels. Sustainable or regenerative agriculture, on the other hand, produces food at the same time as it provides society with ecological goods and services. Sustainable agriculture helps to conserve water, it protects the soil from erosion, and it nurtures biodiversity by creating a hospitable habitat for pollinators rather than killing them with pesticides.

When the Rodale Institute, a Pennsylvania-based organic advocacy not-for-profit, compared the soil health of organic farms and conventional farms in a thirty-year-long side-by-side farming systems trial, they found that conventional agriculture produces 45 percent more greenhouse gases than organic. That's because on agroecological farms, more carbon is sequestered in the soil. The organic soil also held on to nitrogen longer, meaning that less leached away in the water runoff from rain or melting snow. And in times of drought, crops planted in the organic soils fared better because the soil was richer in organic matter and microbes and was therefore better able to support plants under stressful conditions.

A study published in 2009 in the Journal of Cleaner Production found similar results. The study compared the greenhouse gas emissions of organic wheat and conventional wheat. It concluded that conventional wheat production released more carbon dioxide into the atmosphere than organic, largely because of the emissions from the artificial synthesis of nitrogen used to make conventional fertilizer. Another study, published in 2010, found that fields farmed organically supported more butterflies than conventionally farmed fields--an indication that organic agriculture supports more biodiversity.10 Agroecological farms are also more resilient. In October 1998, one of the most deadly hurricanes of the last two hundred years tore through Central America. Hurricane Mitch damaged billions of dollars' worth of industry and infrastructure. Eric Holt-Giménez, executive director of Food First (also known as the Institute for Food and Development Policy), compared how conventional and agroecological farms had fared in the storm. Working with information collected on 880 smallholder plots across Nicaragua, he found that farms where agroecology was practised were more resistant to storm damage than conventional farms. On average, the plots farmed agroecologically retained 40 percent more topsoil after the storm passed and lost 18 percent less arable land in landslides.11 The way these farmers worked the land helped to protect them in the kinds of extreme weather events predicted to increase as we move towards the year 2050.

The industrial food system is praised for the efficiency of its large farms, but it is the small farms that perform better. Many studies have shown that small farms are in fact more efficient at transforming natural resources into foods. If you consider their total food output rather than yield from only one staple crop, small farms produce more food on the same amount of land than large industrial farms do. This is because, whereas large farms tend to grow crops in monocultures--one crop, one field--small-scale farmers practising alternative agriculture will typically plant many different kinds of crops on their land, even sowing a second crop in between the rows (a technique called intercropping). Small farmers also tend to incorporate livestock into general farm production, and work to produce a variety of fruits, vegetables, eggs, meat, and dairy. All this edible output will exceed the amount of food that is grown per unit of land on a large farm.12

The idea that a smaller farm can produce more per hectare than a big farm sounds counterintuitive, but there is a term for the phenomenon: "the inverse relationship between farm size and output"--IR for short. To better understand it, social scientists have built mathematical models that measure the output of different kinds of farms, accounting for variability in land quality and population concentration. They ask questions like, how fertile is the land? And, are farmers in one area simply working harder and growing more food because they live near a large market where they can sell more? While there is some debate in the literature, the overriding consensus is that small farms produce more gross output per hectare per year. Even in parts of the world where farmers use green revolution technology on their small plots of land, it seems that they are able to produce more than their large counterparts.13 Various theories explain this, but the most widely recognized interpretation reasons that small farmers are free to invest more of their labour in their land, thus producing more food. Big farms, on the other hand, have to dedicate resources to managing labour and technology, which eats into their productivity.

This phenomenon is striking in Cuba, where farmers largely have been forced off fossil fuels and into organic agriculture. After the collapse of the Soviet Union, when the country lost a prime source of cheap oil and gas and the United States tightened its trade embargo, the Cuban government had to figure out how to produce food for the island without fossil fuels. Specialists in low-input agriculture from the universities taught farmers how to grow without the green revolution's help. On farms and in cities, organic agriculture took over. Today in Cuba, farmers produce 65 percent of the country's food on only 25 percent of the island's land, growing more per hectare than a commercial farm.14 According to statistics from the Food and Agriculture Organization, Cuba imports grains, pulses, coffee, dried milk, and meat, but is able to produce a wide variety of fruits and vegetables, pork, and dairy. A lot of the organic vegetable production is done in cities, in urban gardens they call organopónicos. News of their success has spread wide, and there are even trips organized for tourists to see what Cubans have accomplished.

Agroecology has many advantages, and small farms can be more efficient than large farms. However, whether or not organic agriculture can produce crop yields per unit of land that are as high as what industrial farms achieve isn't as clear-cut. How much food one way of farming yields over another is an important part of the picture because the amount of food a piece of land produces determines how much land we need to farm and how much land we can leave to be wild. Proponents of industrial food often argue that it is better for the environment because its high yields allow us to spare farmland and leave it fallow. And although there are studies that show organic agriculture outperforms conventional, a lot of research demonstrates that it can't compete. The academic work that supports the idea that organic agriculture is just as productive includes the Rodale Farming Systems thirty-year trial. Not only did it find that organic agriculture delivered ecological benefits but it also recorded organic yields that matched conventional ones. During drought years, organic corn yielded 30 percent more. Yet another study, overseen by Jules Pretty at the University of Essex, looked at how a transition to agroecology improved crop production on more than twelve million farms in fifty-seven countries. It found that sustainable methods increased yields an average of 64 percent, rising to as much as 100 percent in some cases.15 Yet other studies show that conventional farming grows more food.

In our search for the best way to feed the world, it can be hard to make sense of all the conflicting evidence. That's why Verena Seufert, a PhD student in geography, and her colleagues at McGill University decided to study the studies. They extracted data from 125 scientific studies and searched for patterns as well as for factors that could explain variations between results. They found that--it depends! In some cases, depending on soil type and farming practices, organic yields can come close to conventional yields. Mostly, however, they do fall short. Overall, organic yields were 25 percent lower. The team's results were published in the prestigious scientific journal Nature.

I buy organic food. I believe fundamentally in the holistic philosophy of regenerative farming--the idea that we should be cycling nutrients in our food system, striving for ecological balance. I also believe that we should design our food system in whatever way minimizes its environmental burden. So I wasn't sure what to make of Seufert's findings. But she explained to me that although the study isn't a slam dunk for the organics movement, it doesn't prove that industrial agriculture is the answer either.

"Our study shows there is not a yes or no answer to this question," she told me. "We have to look at the context. It depends on how you manage the system. It depends on where you grow crops. It depends on what crops you grow." For example, it is harder to match the yields of organic cereal crops to conventional ones, but organic legumes such as the pigeon peas Chandrakalabai grows, as well as perennials like her sweet lime trees, fare well under organic agriculture. To figure out how to apply this information to the design of the most sustainable food system, we have to understand what explains these differences. And when thinking about yields, one element is key.