Intergovernmental Panel on Climate Change

Environmental Costs of Worldwide Food Production Systems

Image courtesy of Wikimedia.

Image courtesy of Wikimedia.

By Helen Gloege ’23 

Staff Writer


The Paris Agreement, which aims to keep global temperature rise below 2 C above pre-industrial levels and limit temperature increase to 1.5 C, will be hard if not impossible to reach without changes to the worldwide food production system, according to new research from the Nuffield Department of Population Health at the University of Oxford in England. As the food industry continues to grow, food-related emissions are expected to double by 2050, potentially heating the planet more than 1.5 C by the 2060s, and close to 2 C by the end of the century.

A report by the Intergovernmental Panel on Climate Change found that 37 percent of all greenhouse gas emissions come from food production systems, including emissions from transportation and packaging. The emissions come from direct sources such as carbon dioxide, methane and other planet-warming gases. There are also indirect sources such as land clearing and deforestation, both of which allow for agricultural advancements and grazing. In addition, fertilizers, the cultivation of rice and flooded paddies have contributed to these numbers. 

Emissions for carbon-intensive sectors have been decreasing as clean technology is more widely adopted worldwide. Farming has received less attention from policymakers than other greenhouse gas producers, even though it is estimated that half of all habitable land is currently used for agriculture purposes. Agriculture also accounts for 70 percent of freshwater withdrawal. It is estimated that a majority of the global ocean and freshwater pollution is caused by agriculture. 

Another development in food production that contributes to greenhouse gas emissions is monocropping, the agricultural practice of growing a single crop year after year on the same plot of land. This process uses up all the nutrients from the earth, leaving the soil weak and unable to support healthy plant growth. This often forces farmers to use chemical fertilizers to encourage plant growth. Monocropping also fails to provide diversity to diets or ecosystems.

In animal agriculture, concentrated animal feeding operations or factory farms are used to maximize production while minimizing costs. The process involves intensive methods in which poultry, pigs, fish or cattle are confined indoors under strictly controlled conditions in a small, enclosed area. These farms result in excess animal waste and have been linked to high contents of nitrogen and other nutrients in manure runoff that cause dead zones in downstream waterways. These methods of food production use finite resources without replenishing them. 

Leakages of toxic waste also come from concentrated animal feeding operations. Overapplying manure in fields emits nitrous oxide, a greenhouse gas, into the air. This application of manure is carried out to avoid manure leakage into lagoons. A manure lagoon or anaerobic lagoon is a human-made basin filled with animal waste. These lagoons have been shown to harbor and emit substances that can have adverse environmental and health effects. The most prevalent gases emitted by the lagoons are ammonia, hydrogen sulfide, methane and carbon dioxide. Overflow of these lagoons releases harmful substances into the surrounding land or water and may include antibiotics, estrogens, bacteria, pesticides, heavy metals and protozoa. In North Carolina, after Hurricane Florence in 2018, 38 manure lagoons had been structurally damaged, breached or overtopped with nine more lagoons inundated with surface water. When lagoons overflow, untreated waste flows into local waters. 

New advances in sustainable agriculture are rooted in regenerative practices. This means that farmers invest in the land and adopt a holistic ecosystem approach. A report from the Intergovernmental Panel on Climate Change describes following better land practices, switching to less meat-intensive diets and eliminating food waste as global priorities. They also recommend stopping deforestation, limiting greenhouse gas-emitting fertilizers and raising crops that add more carbon to soil. Other goals involve increasing crop yields per hectare and switching to healthy calorie supplies based on plant crops. Dietary changes would mainly need to occur in richer countries where the consumption of meat, dairy and eggs is well above average health recommendations. This allows for a reduction in the consumption of unhealthy, high-carbon foods in large quantities. If this is achieved, it would allow poorer nations to feed their populations better and would increase their consumption of animal products without exhausting the global carbon budget. 

Techniques including organic, free-range, low-input, holistic and biodynamic practices would allow for agricultural sustainability and mimic natural ecological processes. In reality, this would mean farmers minimizing water, encouraging healthy soil by planting fields with different crops, integrating croplands with livestock grazing and avoiding pesticide use by nurturing organisms that control crop-destroying pests. The process of sustainability will also allow for just treatment of farmworkers and food pricing that allows farmers to have a livable income.

Earlier this month, health professionals from the U.K. called for a tax on meat to entice people to change their consumption habits, but taxes are not the only solution. Health professionals explained that meat, tobacco, alcohol, sugar and fuel should be taxed because of the negative impact they have on human health and the environment. Currently, meat is cheaper than most fruits and vegetables, so a tax could be used to increase the availability and affordability of healthy, plant-based foods. This would also allow for sustainable foods to be the easy and affordable choice for those with lower incomes who must often choose meat, the less expensive option, over pricey fruits and vegetables.