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A newly-released report details the environmental footprint of global food production and suggests diet impact is dependent on geography.
A new report authored by Benjamin Halpern, executive director at the National Center for Ecological Analysis and Synthesis (NCEAS) and professor at UCSB’s Bren School of Environmental Science and Management, was published in the peer-reviewed journal Nature Sustainability. It builds on previous research by including land and seafood production and mapping specific regional environmental pressures. These landmark findings are the first attempt to map the impact of food production on specific geographic regions.
Halpern’s study, The Environmental Footprint of Global Food Production, includes an up to 99% of all food production and measures its impacts on land disturbances, greenhouse gas emissions, blue freshwater consumption, and excess nutrient production. The authors use the information to calculate the environmental footprint of each product overall, and by ecological pressure. The data is then mapped by country, leading to the conclusions detailed below.
1. Land contributions account for 89.9% of food’s environmental impact.
Comparatively, oceans account for just 9.9% of food’s environmental impact, and freshwater ecosystems for only 0.2%. While these numbers may seem small, they are significant given that oceans only produce 1.1% of all food products and freshwater ecosystems even less.
For consumers, this may increase confusion about how to reduce our climate impact – if land contributions are responsible for the bulk of the environmental impact of food, should ocean-based product consumption increase? The report does not imply that consumers should move away from eating land-grown food products. The simpler explanation: since land-grown products make up such a large portion of total food production, their environmental disturbances are magnified.
The implications of this finding are more relevant for policymakers and business leaders focused on sustainability. According to the report, “spatial overlap in pressures also identifies where policy can expect co-benefits, where strategies aimed at one pressure (for example, nutrient reduction to mitigate eutrophication) has the potential to benefit another (for example, GHG emissions reduction) and help avoid potential trade-offs, where mitigating one pressure exacerbates another.” Policymakers and business leaders should focus on reducing the impact of land-based food products over ocean-based food products. In doing so, they are likely to mitigate multiple environmental pressures simultaneously.
2. 5 countries are responsible for nearly 50% of the land’s environmental impact.
These countries are India, China, the United States, Brazil, and Pakistan. Interestingly, the impacts of each country are due to different environmental pressures. For example, the environmental impact of food in India is primarily due to water usage, while in Brazil, it is mainly due to greenhouse gas emissions.
Geographical impacts of food can be hard to understand because of complex supply chains and these findings suggest it is vital for governments and businesses in these five countries to develop initiatives to reduce food production’s environmental impact that address the most substantial environmental pressure in their country.
3. Production efficiency for the same crop can vary 4.3 to 17.7 times across countries
This variation is due to differences in technology, water consumption, fertilizer use, and farming practices across different countries. For example, the United States is 2.4x more efficient at producing soy than India because US farmers use more advanced technologies. Similarly, Brazil is 1.9x less efficient at harvesting demersal fish than Russia because Brazilian fisheries rely on more destructive practices.
Because of this variation, it is hard to generalize what diet consumers should follow to have the lowest climate impact. According to Halley Froehlich, co-author of the report, “the environmental efficiency of producing a particular food type varies spatially, such that rankings of food by efficiency differ sharply among countries, and this matters for guiding which foods we eat and from where.” With education and additional resources, consumers can be guided as to which foods are the most sustainable in their region and shift their diet towards those products.
For researchers and policymakers, understanding these variations is especially important. According to the report, “this spatial heterogeneity provides many opportunities for researchers and policymakers to leverage that variation to enhance overall food system sustainability” and more efforts should be made to concentrate the production of certain crops in regions where it is more sustainable to produce them.
4. Cattle and pigs have the highest environmental impact
Unsurprisingly, cattle and pigs are the biggest offenders when it comes to the environmental impact of food. Interestingly, the study finds that the effect of pig farming can be more significant than cattle farming- even though cattle require the most amount of grazing land, pig farming requires enormous amounts of water.
To show the true environmental impact of cattle and pig food products, the researchers included the impact of producing the feedstock that this livestock consumes. The report also accounts for the effects of nutrient pollution from animal waste; this pollution can cause algae blooms in waterways, eventually leading to “dead zones” of water with little to no dissolved oxygen.
For consumers, reducing the consumption of cattle and pig food products will decrease the diet-related environmental impact no matter where they live on the globe. For researchers, businesses, and governments, finding ways to increase the efficiency or reduce the production of cattle and pig-based food products should be a priority. Researchers and companies should also focus on developing alternatives to these products that require less land and water and produce fewer greenhouse gas emissions.
5. 60% of cattle’s environmental footprint comes from greenhouse gas emissions.
This is no small number because of the significant environmental impact of cattle.
Overall, the food system is responsible for nearly 34% of all greenhouse gas emissions, and livestock alone account for 14.5% of this total. Reducing or altering the production of cattle-based foods offers a direct path to reducing emissions.
Policymakers tackling the climate crisis should focus on solutions that provide alternatives to either cattle-based food products or the process of producing these foods. For consumers looking to reduce their contribution to greenhouse gas emissions, decreasing consumption of these foods, in particular, will have a significant impact.
The findings from this report should change how we approach food-production and food-consumption policies and our eating habits and help us move away from a one-size-fits-all mentality. Food policy must be decided at a regional level, with a focus on increasing production and consumption of the most efficiently grown foods locally.
Lead image courtesy Pexels / Kevin Malik.