The way we produce and consume food is inextricably connected to the earth’s changing climate.
Published: 10/08/18, Last updated: 4/14/23
Agriculture is a large contributor to greenhouse gas (GHG) emissions, which are the main driver of climate change. Scientists now predict — and it is already proving true — that there will be extreme shifts in typical weather patterns, like rainfall and temperature. It is also true that climate change poses numerous threats to our current food system, increasing farmers’ sense of risk and uncertainty. Shifting our food production system to more sustainable practices will help reduce agriculture’s role in climate change and also help make this industry become more resilient and adaptable to ever-changing conditions.
All along the food production and distribution chain, there are activities and products that come with varying degrees of associated greenhouse gas emissions. These emissions are known as a “carbon footprint, and the larger a carbon footprint, the larger the contribution to climate change.” (These days, the term “carbon footprint” is used as a catchall phrase for all the climate-change-causing greenhouse gases, not just carbon dioxide or other carbon derivatives.) 3
Not all food is produced in the same manner: some foods use more land, fertilizer (synthetic or organic) and energy and therefore have a greater potential to contribute to climate change — a greater carbon footprint.
A 2017 Natural Resources Defense Council (NRDC) report studied 197 foods, and analyzed their full lifecycle to approximate the climate warming potential of each food. 7 Animals that eat chew their cud (called ruminant animals) also emit significant quantities of methane when their bodies break down the feed in their gut (in a process called enteric fermentation). Methane is also produced by confined animal feeding operations (CAFOs), which process manure anaerobically (without oxygen) in manure lagoons and pits. 9
Globally, livestock contributes 14.5 percent of all greenhouse gas emissions that originate from human activity. 14
Efficiently mitigating livestock’s contribution to greenhouse gases is an important effort, but only one reason to produce beef more sustainably.
26 pounds
of carbon dioxide are emitted when one pound of feedlot beef is produced
Anaerobic manure digesters are sometimes promoted as a means by which confined animal feeding operations (CAFOs) can dispose of their animal waste in a manner that is more environmentally and climate friendly. Digesters use a combination of microbes, heat, water and agitation to process waste, producing methane gas that can be used for energy, liquid manure that can be used for fertilizer and solid manure that can be used for composting and cow bedding.
Despite federal and state financial investments for the new technology, there is growing skepticism about digesters. A 2016 report by Food and Water Watch details the ways in which digesters do not live up to their promise of cleaning waste and mitigating greenhouse gases — and instead serve as a subsidy to the CAFO industry, further entrenching the confinement model of food production. 15 According to Food and Water Watch, digesters do not capture all of the methane they produce, and in burning methane, produce GHG carbon dioxide and nitrous oxide, as well. 16
Synthetic nitrogen (N) fertilizers are produced from fossil fuels (like coal and natural gas) and are used extensively in conventional crop production. Globally, the use of synthetic fertilizers contribute to about 13 percent of agricultural GHG emissions. 17
While nitrogen fertilizers have improved yields worldwide, recent studies indicate that the increased use of nitrogen-based fertilizers over the last 50 years has increased the rates of nitrous oxide emissions exponentially, as compared with the rate of use of other fertilizers. 18 What this means is a large rise in atmospheric nitrous oxide — a greenhouse gas 300 times more potent than CO2.
As discussed above, conventional land use management practices for crop or animal production can act as a carbon source, while more sustainable practices can act as a carbon sink — sucking up and storing the carbon dioxide from the atmosphere.
A farming practice called “tilling,” turning over and breaking up the soil, can expose carbon that was locked in the soil and can facilitate erosion. This means that low-till or no-till farming is a more sustainable option. One of the larger carbon sources is the expansion of cropland, i.e. cutting down forests and eradicating grassland, for growing conventional animal feed and creating land for grazing livestock. This means that two thirds of available agricultural land worldwide is now used for animal production, which includes marginal land for grazing and other land used for feed crops. Some incentives, like rising crop prices, may make taking land out of conservation more attractive to farmers, in turn eliminating that carbon sink. 20 For example, when many trees are clear cut, this loss alters the water cycle in a specific climate: this can result in local climate change. Likewise, when forests are burned down for agricultural purposes, the burning trees release their sequestered carbon into the atmosphere, adding to greenhouse gas emissions: this can result in climate change locally and globally.
It is not only climate change that is of growing concern, but biodiversity loss, as well. Deforestation goes hand-in-hand with the loss of species within a given ecosystem. Broadly, biodiversity loss can cause disruptions in ecosystems, which in turn can produce a wide range of negative effects, including soil, water and air degradation. 25 In general, climate change results in extreme temperatures, extreme and unpredicatable weather events and extreme precipitation or drought. Some parts of the country are becoming wetter or dryer, are experiencing more heat waves and are suffering from prolonged drought. Since agricultural practices are developed to interact with the local or regional climate, changing climates are negatively affecting growing seasons and animal health. If conditions become too extreme, some currently productive agricultural areas may need to relocate or adapt to the new conditions. 27 Extreme precipitation can cause soil erosion and may impact the ability of farmers to control water systems with the current methods of field drainage. And drought could be more prevalent in other areas. Many pests thrive in warmer climates, which could pose an additional threat to crops and, in conventional crop production, will necessitate more pesticide use. 29 Finally, rising atmospheric CO2 levels may also be affecting the nutritional quality of crops, decreasing their protein content. 35
In general, farmers have three options to harness the benefits of wind power on their farm. First, farmers can use a wind turbine to generate electricity on the farm to be used for the home or operations. Second, farmers could work with a wind developer, providing land and deriving lease payments as another revenue stream. Finally, farmers could develop their own wind farms and sell the electricity into the market. 36
In sum, solar and wind energy together offer several options for farmers to reduce their carbon footprint, while potentially adding economic benefits to generate income or to save on energy bills. These alternative energy technologies also provide marketing strategies for farmers to promote their products, as well as potential educational opportunities for farm visitors.
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