Feed the World, Save the Earth

These two goals need not—must not—be mutually exclusive.

The defining feature of earth is the existence of life, and the most amazing feature of this life is its incredible diversity. How and why this planet supports more than 3 million different species of plants and animals has fascinated biologists for at least the past two centuries. What began as academic curiosity, though, has become a subject of importance for the long-term sustainability of Earth’s ecosystems and the vital services these ecosystems provide to society. We now know that loss of biological diversity compromises the productivity, stability and efficiency of ecosystems, and that human actions are threatening biodiversity.

What does this have to do with food production? We already use an immense part of the Earth to produce our food. Once deserts, the Antarctic and tundra are excluded, Earth has about 8 billion hectares of land that is generally suitable for humans. Five billion hectares are currently dedicated to agricultural cropland and pastures, and more than a billion more hectares may be needed to feed the world by 2050. This conversion of a third to a half of the Earth’s remaining high-diversity natural ecosystems into low-diversity agricultural ecosystems would be a major threat to global biodiversity.

We face a dilemma. Providing all the people of the world with an adequate and sustainable supply of food is a central moral obligation of society. We are likely to need more than double the current global food supply as global population grows from 7 billion to 9 billion people and especially as per capita consumption increases by about 150 percent. However, it is also our obligation to ensure that future generations have a livable planet. Human impacts on nature, which are already large, are likely to be two or three times stronger by the middle of this century if we expand agri­culture as we have during past decades.

Can we feed the world and save the Earth? The richer nations currently have crop yields that are four to six times larger than those of the less developed nations. If we can provide the less developed nations of the world with the knowledge and resources needed to close this yield gap on the lands that they have already cleared, it is possible that we could more than double global food production within 50 years without requiring more global land clearing. Moreover, during the past 15 years, at least a dozen nations have been able to increase their yields while decreasing agrichemical inputs through “precision agriculture.” The global adoption of precision agriculture would help ameliorate the pollution of lakes, rivers and the oceans that would otherwise be caused by agricultural intensification.

More than a billion people living in the world’s least developed nations suffer from malnutrition and inad­equate diets. If they are provided with the tools to greatly increase their yields, it will be possible both to feed the world and to save the remaining ecosystems of the Earth and their biological diversity.

David Tilman is a Regents professor and McKnight presidential chair in ecology in the University of Minnesota’s College of Biological Sciences, a member of the National Academy of Sciences, and a resident fellow at the Institute on the Environment. The Institute for Scientific Information designates him as the most highly cited environmental scientist of the decade. He is the recipient of the 2010 Heineken Prize for Environmental Sciences and the 2008 International Prize for Biology.

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