Energy has always been essential for the production of food. Prior to the industrial revolution, the primary energy input for agriculture was the sun; photosynthesis enabled plants to grow, and plants served as food for livestock, which provided fertilizer (manure) and muscle power for farming. However, as a result of the industrialization and consolidation of agriculture, food production has become increasingly dependent on energy derived from fossil fuels.
Today, industrial agriculture consumes fossil fuels for several purposes:
Industrial farms use huge quantities of synthetic fertilizers, which require significant energy inputs (primarily natural gas) to be produced. Other fertilizing agents (e.g., potassium and phosphorus) are mined, consuming even more energy.
Industrial agriculture is incredibly water intensive. The scarce resource is used for crop irrigation, which accounts for 31 percent of all water withdrawals in the US, waste management (i.e., for flushing manure out of industrial livestock facilities) and as drinking water for animals. This overuse of water has implications in the energy sector as well. As described in our Energy-Water Nexus page, pumping, treating and moving such large volumes of water require a great deal of energy.
Modern agriculture relies upon machinery that runs on gasoline and diesel fuel (e.g., tractors and combines), and equipment that uses electricity (e.g., lights, pumps, fans, etc.).
Much of the food produced today is highly processed and heavily packaged, which further increases its energy footprint. As a result of consolidation and centralization of production, foods are often transported long distances, requiring additional energy inputs.
Most meat, eggs and dairy products are now produced on factory farms, huge industrial livestock operations that raise thousands of animals in confined conditions without access to pasture. Since the animals are unable to graze, factory farms require tremendous quantities of feed produced by industrial crop farms using the energy-intensive processes described above. Factory farms are also potential sources of ground and surface water pollution, which ultimately requires municipalities and private landowners to expend additional energy on water treatment.
Some factory farms use methane digesters to generate energy (digesters capture methane released during the decomposition of the huge quantities of manure generated onsite, and then burn the gas to produce electricity). Although this reduces emissions of methane (a potent greenhouse gas), the technology doesn’t eliminate solid waste, fails to address other environmental, human health, social and animal welfare problems created by factory farms, and typically requires large subsidies to remain economically viable. Thus, despite being touted as a “green” energy source, methane digesters ultimately serve to subsidize and further entrench the environmentally and socially destructive model of industrial livestock production.
Energy policy also affects agriculture. For instance, congressional mandates now require the production of billions of gallons of ethanol, which is primarily—and controversially—derived from corn. Corn grown for ethanol takes land away from food production and, in states where corn is irrigated, uses a significant amount of water.
Given the growing population’s food requirements, the world’s finite supply of fossil fuels and the adverse environmental impacts of using this nonrenewable resource, the existing relationship between agriculture and energy must be dramatically altered. Among the most obvious solutions is to simply improve the energy efficiency of food production and distribution. This can be accomplished by shifting from energy-intensive industrial agricultural techniques to less intensive methods (e.g., pasture-raised livestock, drip irrigation, non-synthetic fertilizers, no-till crop management, etc.), using more efficient machinery and equipment, reducing food processing and packaging, promoting decentralization of food production and improving the efficiency of food transportation.
Farms can also generate their own clean electricity. While houses, barns and other buildings provide ample roof space for the installation of solar panels, farms with large swaths of land in windy areas are ideal sites for wind turbines. By leasing property for wind power production, these farms can earn an additional source of revenue while continuing to grow crops on surrounding land.
Despite the challenges posed by the energy-intensive nature of agriculture, the prudent use of resources and judicious application of technology has the capacity to significantly improve the long-term sustainability of food production.