Environmental impacts of food systems
Food systems rely on and deplete natural resources, and food systems cause negative impacts on the environment. Here we discuss ways in which food system activities impact the environment, while highlighting the benefits of making more efficient and sustainable use of natural resources - something we will return to in Week 5: Towards sustainable food systems.
All food system activities impact the environment. Many of those impacts are intrinsically tied to the use of natural resources. Converting forest to farmland leads to greenhouse gas emissions, as does the use of fossil fuels for energy. The use of water for irrigation can change river flows, reduce water quality, and affect downstream ecosystems. Overfishing can deplete fish stocks and reduce biodiversity. Minerals used in fertilizers can leach into the ground and into bodies of water.
Food systems cannot stop using natural resources – they depend on those resources. Key activities such as crop and livestock production and aquaculture also rely on open systems, based on natural processes. That makes them subject to unpredictable factors such as weather, with some unavoidable impacts. At the same time, human-made materials and substances, such as pesticides, antibiotics, hormones and plastics, can lead to contamination, affecting air, water and soil quality.
As food system activities harm the environment, they may also reduce the availability of resources needed for food systems, and for other activities. For example, if water quality is degraded, it may no longer be suitable for irrigation – much less for drinking. Sometimes these feedbacks are very local and immediate – such as with water contamination. Others, such as climate change driven by greenhouse gas emissions, occur on a global scale, over several decades.
The impact of food system activities on our planet has been huge. On land and in the water, biodiversity has declined largely because of food system activities. Agricultural intensification through the use of chemical fertilisers, pesticides and irrigation has greatly increased crop yields, but it has also harmed soils and water bodies. Soils have lost organic matter, eroded, and have become hard, compact and saline. Rivers, lakes and seas are polluted and sometimes filled with algae due to excessive nutrients in the water (a process called eutrophication). Large areas have been converted to farmland, fragmenting habitats and reducing biodiversity.
Agricultural intensification has also made food production more expensive, as energy prices rise and natural resources are strained. To feed a growing population, we will need to produce even more food, but without further harming the environment. The good news is that by using natural resources more efficiently and sustainably, we can reduce environmental impacts and achieve multiple benefits. For example, more targeted use of fertiliser can avoid waste and runoff while also reducing the use of minerals and energy – which leads to lower carbon emissions. However, there is an alternative hypothesis that intensification might actually reduce the extent of land use change and environmental degradation, known as the Borlaug Hypothesis.
Nevertheless, more and more, researchers looking to boost agricultural productivity are focusing not on the plants or animals involved, but on how to use inputs more efficiently and reduce negative impacts. This is where the food systems approach comes in: It looks at the full set of activities and actors involved in the “food chain” (i.e. producing, processing, distributing, selling and consuming food), including their socio-economic context, and examines the implications of those activities for food security.
UNEP (2016). Food Systems and Natural Resources. A Report of the Working Group on Food Systems of the International Resource Panel. Westhoek, H, Ingram J., Van Berkum, S., Özay, L., and Hajer M.
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