Environmental Impact of Food Production

Environmental Impacts of Food and Agriculture

• 26% of greenhouse gas emissions come from food production.
• Agriculture utilizes 50% of the world's habitable land.
• Agriculture accounts for 70% of global freshwater withdrawals.
• Eutrophication results in 78% of global ocean and freshwater pollution.
• Livestock constitutes 94% of global mammal biomass excluding humans.
• Poultry livestock represents 71% of global bird biomass.

Carbon Dioxide Equivalents (CO2-eq)

• CO₂ is a major greenhouse gas, but agriculture also contributes methane (CH4) and nitrous oxide (N2O).
• CO2-eq compares emissions from various greenhouse gases using their global-warming potential (GWP), converting them to the equivalent amount of carbon dioxide.
• Researchers use 'carbon dioxide equivalents' (kg) to capture all GHG emissions from food production for comparison.

Greenhouse Gas Emissions per Kilogram of Food Product

• Greenhouse gas emissions are measured in kilograms of carbon dioxide-equivalents.
• Non-CO2 gases are weighted by the amount of warming they cause over a 100-year timescale.
• Plant-based protein sources have a lower footprint than the lowest-impact meat products.
• Ruminant animal products include beef (beef herd), lamb/mutton, and beef (dairy herd).
• Beef (beef herd) creates 99.48 kg of CO2
• Lamb and mutton create 39.72 kg of CO2
• Dairy (beef herd) creates 33.3 kg of CO2
• Plant-based products like nuts create 0.43 kg of CO2.

Carbon Footprint of Protein-Rich Animal-Based Foods (kgCO2-eq per 100g protein)

• The median global footprint for beef is 25 kgCO2eq.
• 10% of beef producers emit >105 kgCO2eq per 100 grams.
• Another 10% of beef producers emit <9 kgCO2eq.
• Most beef production falls between 17 and 27 kgCO2eq.
• The median global footprint for lamb/mutton is 20 kgCO2eq.

Carbon Footprint of Protein-Rich Plant-Based Foods (kgCO2-eq per 100g protein)

• Tofu, with the highest footprint among plant-based proteins, has a median of 1.6 kgCO2eq.
• Pea producers emit 0.36 kgCO2eq, for the median footprint
• Nut producers emit -0.8 kgCO2eq for the media fotoprint, acting as carbon negative as trees capture CO2.
• Plant-based protein sources have a lower emissions impact than the best cheese and pork, with their footprint being 4.5 kgCO2eq.
• Emissions are slightly lower or comparable to those from the lowest CO2-eq footprint chicken (2.4 kgCO2eq).

Consumption Choices for Lower Environmental Impact

• Eating less meat, specifically ruminant animal meat, and reducing dairy consumption can lower your dietary footprint.
• Switch to lower impact meats like pork, chicken, and eggs for a reduction in dietary footprint.
• Choose food sources with lower environmental impact; e.g., avoid beef from South America due to deforestation.
• Eating more plant-based protein sources compared to fewer animal-based sources of protein will benefit planet impact.

Environmental Footprints of Dairy and Plant-Based Milks

• These impacts measured are per liter of milk, and are based on a food system impact studies meta-analysis across the supply chain, including transportation, production, packaging and more.
• Dairy milk has a land use impact of 8.95m2, compared to Oat milk which has a land use impact of 0.76m2.
• Dairy milk has a freshwater use footprint of 628.2 L, compared to Soy milk which has a freshwater use footprint of 27.8 L.
• Dairy milk has greenhouse emissions of 3.15 kg, compared to Almond milk with greenhouse emissions of 0.7 kg.
• Dairy milk has an eutrophication impact of 10.65g, compared to Soy milk with an impact of 1.06 g.

Cow's Milk vs. Plant-Based Milk Alternatives

• Cow's milk causes 3 times as much GHG emissions and uses about 10 times as much land.
• The freshwater consumption is 2-20 times higher, with much higher levels of eutrophication compared to plant-based alternatives.
• Protein in 1 litre includes 32g of cow's milk, 8.5g in soy, 2.5g in almond, 0.7g in rice and 0.5g in oat.
• Cow's milk is best for children and those on a low diversity diet who may not be getting enough protein

Other plant-based milk alternatives

• 95% of Brazil's soy crop is used for animal feed.
• Globally, >75% of soy is used for animal feed, by mass.
• Most of Brazil's soy crops are genetically modified.
• Yields per hectare are similar or better in the EU compared to Brazil and South America.
• 2.9 tons in Brazil
• 3.0 tons in France
• 3.3 tons in Spain
• 4.0 tons in Italy
• Environmental impact of EU soy is lower than South American; buying from South America can be a big problem.

Food: Greenhouse Gas Emissions across the Supply Chain

• Land use dominates aboveground, especially in the transport of food items in-country and internationally.
• Pigs and poultry are non-ruminant livestock, meaning they do not produce methane and have significanly lower emmissions than beef of lamb.
• CO2 emissions from most plant-based products are much lower than most animal-based products
• Factors such as retail, transport distance, packagaing have small importance compared to the food type.
• The answer is in food choices and avoiding air-freighted foods where possible.

Energy and Protein Conversion of Meat

• A Sankey flow diagram illustrates the US feed-to-food caloric flux, converting 1187 Pcal of feed into 83 Pcal of edible animal products.
• This reflects approximately a weighted mean conversion efficiency of 7%.
• The U.S feed-to-food protein flux from the three feed classes turns 63 Mt of feed protein into edible animal products that contain 4.7 MT Protein , an 8% weighted mean protein converstion efficiency.

Organic vs Conventional Farming

• Organic farming prohibits synthetic inputs (synthetic fertilizers, pesticides, plant growth regulators, nanomaterials, GMOs).
• Organic farming allows certain chemicals, but they cannot be synthetically manufactured except for a few approved by national organic standards boards.
• Conventional farming uses an agricultural system with synthetic inputs.
• Nutrients added to soil in organic farming come from organic matter (green compost, animal manure, bone meal).
• Animals must be fed organically-certified feed.
• Antibiotics can only be used in emergency cases such as disease or infeciton outbreaks.
• There are no constraints on feed certification or antibiotics or hormones for growth in convetional farming

Environmental Impacts: Organic vs. Conventional Agriculture

• Data reflects a meta-analysis of 164 published life-cycle analyses from 742 agricultural systems focusing on resource and ecological indicators.
• Organic agriculture is defined without synthetic inputs, like fertilizers, pesticides, plant growth regulators, nanomaterials, and GMOs).
• Impact ratios higher than 1 indicate larger environmental impacts from organic methods.
• Values less than 1 indicate smaller impacts.

Comparison of Land Use, Energy Use, and other factors

• Organic systems perform worse in land use regardless and have more impact than conventional systems due to the impacts of pesticide and fertilizer usage.
• Exception to this is vegetables, where energy use in organic systems is higher due to use of alternative methods of weed and pest control e.g. use of propane-fueled flame weeding and associated machinery
• Average values in organic production for Eutrophication are worse than they are for conventional production.

Comparison of Food choice impact (CO2 footprint based)

• GHG emmissions are relatively the same for both Fertilizers and Manure.
• Conventional farming scores better and more environmentally friendly compared to organic when it comes to land use.
• Both Eutrophication and acidification are better in conventional, compared to organic -Conventional has negative impacts on local biodiversity caused by herbicide and pesticde us.

Global Land Use for Agriculture across Different Diets

• Current global diet uses 704 Mha for human food and 538 Mha for animal feed.
• Adopting a vegan lifestyle leads to an area the size of North America, plus Brazil being freed up regarding agricultural land use.
• The total is 4.13 billion ha that can be freed up with this impact.

Take Home Message

• Supply and demand affects productuon, producers will produce only what is demanded
• Diets are imbalanced with too much meat and milk being consumed
• Sustainable diets limit ruminant meat and milk and increased plant-based proteins instead.
• Land reclaimed with sustainable land use affects health, the planet and biodiversity.
• Reclaimed land enables regrowing forests and habitats while storing much more carbon.
• Social responsibility needs changes in our eating and habbitual behaviours