Food and Biofuels Ecological Footprint
by Dr. Mark Edwards
he four primary metrics that examine sustainable food and biofuels are life cycle analysis, ecological footprint, freshwater footprint, and carbon footprint. The proposal here suggests a food and biofuels footprint can improve our understanding of production alternatives. LCA, also known as ecobalance, is a technique to assess environmental impacts associated with all the stages of a product’s life from-cradle-to-grave. For food and biofuels, LCA examines environmental impacts from raw material extraction through materials processing, manufacture, distribution, use, repair and maintenance, and disposal or recycling. Lifecycle analysis does not measure the threat of resource extinction.
An ecological footprint creates a metric for human demand on the Earth’s ecosystems. The footprint compares human demand with our planet’s ecological capacity to regenerate. For 2006, humanity’s total ecological footprint was estimated at 1.4 planet Earths. This means current societies use ecological resources 1.4 times as fast as Earth can renew them. Scientists recalculate the metric annually, with a three-year lag due to the time necessary for the UN to collect and publish the underlying statistics. The full e-footprint calculation considers housing, transportation, recreation and food consumption.
The freshwater footprint measures the consumptive use of freshwater. Water that is recycled such as household use that is reclaimed and reused is called non-consumptive water. Freshwater used for agricultural purposes and food refining is consumptive because the water is not available for reuse.
A carbon footprint measures air pollution, as a derivative of the ecological footprint. A carbon footprint creates a metric for the total set of greenhouse gas emissions caused by any human activity. For foods, the carbon footprint typically expresses the amount of carbon dioxide, or its equivalent of other GHGs, emitted from production, transportation and consumption.
The food e-footprint covers a wide variety of ecological factors but does not consider the possibility of resource extinction. Food production represents a special case where each of 24 fossil resources must be available to crops precisely on time or the crop fails. When farmers find one fossil resource unavailable or unaffordable, they may lose their entire crop. Unfortunately, many of the vital fossil resources face extinction, especially in specific food growing regions.
The e-footprint for food or biofuel consumption provides a broader metric than air pollution but narrower than the total ecological footprint. The e-footprint for food creates a metric that reflects the natural resources required to provide a consumer with food. The food e-footprint considers production, waste, risk, transportation, and pollution. The creation of a food e-footprint provides a means to measure one’s impact on the planet. Most people are not aware of their food footprint. Self-awareness provides the first and necessary step for behavior change. Footprint calculations offer policy makers a set of standards that help in formulating sustainable food policy. The food e-footprint may help political, medical and business leaders make recommendations to improve our food supply.
People that eat high on the food chain consume large amounts of dairy and meat products and leave a large e-footprint. Vegetarians diminish their footprint far lower than meat consumers do, but still substantially higher than consumers that eat freedom foods.
Vegetarians leave a modest ecological footprint, not by choice but due to the way producers grow industrial foods. Each ton of grain consumes about 1000 tons of freshwater, as well as considerable cropland, fuels, fertilizers and chemicals. Often, 60% of food is lost in the field or the food supply chain. Industrial food production creates significant pollution, carries substantial physical and economic risk to farmers. Industrial foods continually extract soil nutrients, erode soil and pollute ecosystems. Industrial crops are weather intolerant, elevating the risk of crop failure.
The USDA reports that in 2007, U.S. cattlemen used two billion bushels (112 billion pounds) of corn to produce 22.16 billion pounds of finished grain-fed beef. Farmers used 13.3 million acres to produce the feed grains, since corn production averages about 150 bushels per acre. Each pound of beef releases about 22 pounds of CO2-equivalent greenhouse gasses. Consequently, a single year of beef production releases roughly 2.5 trillion pounds of CO2-equivalent greenhouse gasses. Cars add about 2.7 trillion pounds of new carbon the atmosphere each year.
David Pimentel calculates a steer consumes about 100 pounds of grain per pound of edible beef produced. Using the basic rule that it takes about 264 gallons of water to produce one pound of hay and grain, about 26,400 gallons are required to produce a pound of beef.
Biofuels also create a substantial environmental footprint. Biofuels compete with food, accelerate fossil resource depletion and amplify soil erosion and pollution. Each gallon of ethanol consumes 3,000 gallons of freshwater to produce the corn feedstock. When drawn from fossil aquifers that do not replenish with annual rains, the water is not available for future generations – for food or biofuels. Much of the cropland west of the Mississippi River draws irrigation water from fossil aquifers and several are predicted to run dry in a generation.
The Renewable Fuels Association reported that in 2010, producers converted 260 billion pounds of corn into 13 billion gallons of ethanol. Ethanol has 64% of the energy of gasoline so that is 8.3 equivalent gallons of gasoline. In 2010, U.S. farmers harvested nearly 400 million tons of grain, of which 126 million tons, primarily of corn, went to ethanol fuel distilleries. Each acre of corn production releases about 4500 pounds of CO2. Therefore, ethanol feedstock adds another 700 billion pounds of CO2 to the atmosphere.
The peer-reviewed ecological footprint for food consumption remains to be constructed. The draft proposal here collapses several ecological categories to create a 100 point metric. Beef resides at the top of the food chain, because beef requires a high multiple of the resources required by grains and other foods low on the food chain. A Food ecological footprint might include the dimensions shown in the table.
Freedom foods avoid most of the resource consumption, pollution, risk, and weather problems that plague fossil foods. Freedom foods offer a drill-down on how algae-based foods and biofuels can minimize the e-footprint on each of the salient dimensions. Growing freedom foods can repair air and water pollution and regenerate soils. Therefore, freedom foods consumers leave a tiny ecological footprint.
The e-footprint for organic produce is probably around 50/100. Organic foods consume more ecological resources than industrial foods, except for fertilizers, chemicals and poisons. Some organic farmers produce close to consumers and many enrich local communities.
The e-footprint for corn biofuels approaches 70/100. Corn requires intense application of natural resources. Corn production is extremely pollutive. A single acre of corn gives off about 4,000 gallons of water each day from evapotranspiration. Corn requires ten times more nitrogen fertilizer than other food grains, which is not only consumptive but also extremely pollutive. Fertilized soils release more than two billion tons of greenhouse gases every year, especially CO2, methane and nitric oxide. Each acre of corn production adds 2.25 tons of CO2 to the air, plus nitric oxide that has 296 times the warming capacity of CO2.
Each cropland acre loses about 54 pounds of nitrogen, 13 pounds of phosphorus, 264 pounds of potassium and 132 pounds of calcium annually, which is typically replaced with mined chemicals. Corn grows in rows, which amplifies soil erosion. Each acre of corn erodes over 6 tons of topsoil, in normal years. In 2011, with the extreme rains and floods, topsoil erosion was a high multiple of 6 tons per acre.
Algae-based biofuels could yield an e-footprint of 20 or lower if producers use waste or brine water for nutrients and waste CO2 for their carbon source. Growers could also avoid most fossil fuels by using renewable energy from wind, waves, geothermal or solar energy.
The food ecological footprint does not account for food health issues or the use of GE crops. Michael Pollan, The Omnivore’s Dilemma, Jeffrey Smith, Seeds of Deception, and Marie-Monique Robin, The World According to Monsanto, cover the health and GE crop issues effectively.
No one has quantified the e-footprint for food and biofuels. The proposal here begins the process. Please engage with your ideas and extensions.
Adapted from: Edwards, Mark R. Freedom Foods: Superior Nutrition and Taste from low on the Food Chain for People, Producers and Our Planet, CreateSpace, 2011.