Environmental Impacts of Food Production

The plant food system links to environmental costs Seed – genetic impacts on wild species Soil - land transformation to get access to soil Water – irrigation demand Nutrients - pollution Sunlight- once land is cleared no cost Temperature- no costs Air- benefits through CO2 absorption Protection from weeds, pests- erosion, pesticide pollution

The green revolution Genetic improvements in cereal grains Synthetic fertilizers Added use of pesticides More use of irrigation

Expanded land use and loss of native habitat

Gibbs, H. k., Ruesch, A. S., Achard, F., Clayton, M. K., Holmgren, P., Ramankutty, N., and Foley, J. A Tropical forests were the primary sources of new agricultural land in the 1980s and 1990s. Proceedings of the National Academy of Sciences of the United States of America.

Soil Erosion Agriculture and grazing cause soil to erode at much faster rates than natural erosion Entire civilizations have disappeared due to erosion 30% of the earths topsoil has eroded in the last 30 years Iowa has lost 1/3 of its topsoil since the arrival of the plow Not only do we lose potential productivity, the erosion causes flooding, fills reservoirs etc. Removal of native vegetation, and soil disturbance by the plow and livestock are the primary causes of rapid erosion

Water use and demand Water is in short supply over much of the world Crops require water – increasingly from irrigation This generates conflicts over water use

Water Wars Sacramento River Columbia River Turkey-Iraq

Water quality Nutrient run off from crops and animal feed lots causes lots of problems Polluted Fresh Water Dead Zones

From Cassman et al.

Dead Zones

Pesticides

Antibiotics

Flesh eating bacteria

Genetic impacts Loss of native strains of domesticated plants and animals – associated diversity of genetic characteristics (climate change, disease) Contamination of non-domesticated crops and animals by domesticated genetic characteristics – GMO crops – Farmed Salmon

Carbon footprint Producing food produces atmospheric carbon – Fuel for tractors, machines, transportation, refrigeration – Land clearance produces large pulse of atmospheric carbon as native habitat is removed – Beef and sheep produce methane as part of their digestive process

Biodiversity loss Land transformation Impacts from other causes - pollution, genetics etc. Wild population exploitation (fisheries and bushmeat)

What is the environmental cost of organic vegetable production

Substantial loss of native biodiversity in this organic vegetable field

Biodiversity impacts Land use for aquaculture probably similar to agriculture But the recovery time of the ecosystems is probably much less – Take out the salmon farm or shellfish farm and it won’t take too long to return to a natural state

Markus Borner’s dilemma

Environmental costs of food production Greenhouse gases Water use Pollution, fertilizer and pesticides Antibiotics Soil erosion Biodiversity loss

How to compare the costs Literature review of Life Cycle Assessments All costs standardized to a single portion of 40 g of protein All costs are production costs, at the farm gate or ex-vessel, no transport, wholesale or retail costs generally available

Environmental costs per 40g protein #1 Production method Water use Liters Fertilizer Grams Pesticides milligrams Antibiotics milligrams Soil Loss kg Beef Chicken Pork Dairy ?7 Capture fisheries low03000

Environmental costs per 40 g protein #2 Production method Land Required m 2 CO 2 with land use kg CO 2 without land use kg Beef Chicken Pork Dairy Capture fisheries

What is missing These data are at the farm gate or ex-vessel off the boat There are considerable environmental impacts of transportation, processing, retail

Summary All forms of food production have environmental costs These differ greatly among alternative types of food

The End

Study Questions List 4 necessary elements of crop production and the associated environmental impacts What fraction of new land brought into agriculture since 1980 has been native forest? What is the most significant difference in land transformation since 1980 in India compared to Indonesia? What 2 factors primarily determine the rate of soil erosion in a specific place. Contrast the environmental consequences of using groundwater vs river water for irrigation. How does the use of fertilizer lead to “dead zones” in the ocean Why is the Gulf of Mexico so prone to dead zones? Why were eagles and pelican especially vulnerable to impacts from DDT? How are antibiotics used in the production of food? What is MRSA? Give an example of a genetic impact of food production What are the three primary ways that food production causes an increase in greenhouse gasses? What fraction of US greenhouse gas production comes from on the farm agriculture? List three ways that food production impacts biodiversity. For what measures of environmental impact do capture fisheries look better than most forms of agriculture including crops?

Next steps Write up what has been done Add aquaculture and crops Work on biodiversity costs Add processing, wholesale and retail Make results widely available