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Another Inconvenient Truth: the adverse effects of animal foods on the environment Paul Appleby (with thanks to Nigel Winter and Stephen Walsh) Oxford Friends Meeting House 9 March 2007 Some quotes • Livestock are one of the most significant contributors to today's most serious environmental problems. Urgent action is required to remedy the situation. UN Food and Agriculture Organisation official Henning Steinfeld • If the impacts of climate change are as bad as predicted we may need to go back to (food) rationing. Environment Minister Ben Bradshaw MP • The world must create five billion vegans in the next several decades, or triple its farm output without using more land. Dennis Avery, Director of the Center for Global Food Issues,The Hudson Institute • Each of us could make a bigger contribution to reducing emissions of greenhouse gases by becoming a vegan than by converting to an eco-friendly car. Environmental campaigner Jonathon Porritt Production of animal foods • Worldwide meat production reached 265 million tons in 2005, equivalent to 42 kg per person • Global meat production has increased fivefold since the 1950s and more than doubled since the 1970s • Meat production is projected to increase to 465 million tons in 2050 • Milk production is projected to increase to over 1000 million tons in 2050 (from 580 million tons in 2000) Livestock numbers More than 50 billion animals are slaughtered for food each year At any one time we share the planet with • 15 billion poultry • 1.3 billion cattle • 1.7 billion small ruminants (sheep, etc) • 0.9 billion pigs The world’s human population of 6.5 billion is projected to increase to 9.1 billion by 2050 Land use and degradation Livestock production accounts for 70% of all agricultural land (including 33% of arable land used to grow feed) and 30% of the land surface of the planet About 20% of the world’s pastures and rangelands have been degraded to some extent (73% of rangelands have been degraded in dry areas), mostly through overgrazing, compaction and erosion caused by livestock 70% of previously forested land in the Amazon is now pasture (and most of the rest is used to grow feed, principally soy beans) Is land used efficiently? 1200 1057 Pounds of protein per acre 1000 814 800 708 600 400 306 318 245 218 200 96 0 Soya Potatoes Wheat Rice Eggs Milk Pork Beef A vegan diet uses half the amount of land used to produce a vegetarian diet and one fifth of that used for a European omnivorous diet. (Calculations by Stephen Walsh using data from Gerbens-Leenes et al, A Method to Determine Land Requirements Relating to Food Consumption Patterns, 2002; FAOSTAT, 2006; and The Composition of Foods, 6th Edition, 2002.) Kilograms of protein required to be fed to an animal to produce one kilogram of animal protein Source: Council for Agricultural Science and Technology Water scarcity and water use “The world is moving towards increasing problems of freshwater shortage, scarcity and depletion, with 64 percent of the world’s population expected to live in water-stressed basins by 2025” (UN FAO). Already, more than 1 billion people lack enough safe water to meet minimum levels of health. “Food and agriculture are by far the largest consumers of water. They require one thousand times more than we use to drink and one hundred times more than we use to meet basic personal needs” (World Water Development Report, 2003). Litres of water used to produce one kilogram of various foods (according to various sources) Food Pimentel Beef 100000 Lamb Chicken 3500 Soya beans 2000 Grains Rice 1910 Maize (corn) 1400 Wheat 900 Potatoes 500 Reijnders S.I.W.I. 20000 15000 (or more) 10000 6000 750 400-3000 4700 (irrigated) 1400 The net amount of water required for a 3000 kcal/day mixed diet with 20% animal foods has been estimated as 1300 cubic metres per person per year, whereas for a purely vegetarian diet it is about half as much. (Water - more nutrition per drop, Stockholm International Water Institute & International Water Management Institute, 2004) Water pollution • “The livestock sector accounts for over 8% of global human water use and is probably the largest sectoral source of water pollution” (UN FAO) • US livestock are responsible for an estimated 55% of erosion and sedimentation, 37% of pesticide use, 50% of antibiotic use, and one-third of the nitrogen and phosphorus contamination of freshwater • 200 million tons of undiluted excreta are produced on UK farms each year • Of the 4254 UK agricultural pollution incidents in 1999, more than two-thirds arose from livestock rearing compared with 7% from arable farming Threats to biodiversity • Species loss is estimated to be 50-500 times higher than background rates • Livestock production is the main cause of deforestation, and a major cause of land degradation, pollution, climate change, overfishing, and sedimentation of coastal areas • 23 out of 35 global biodiversity hotspots identified by Conservation International are affected by livestock production • “The livestock sector may well be the leading player in the reduction of biodiversity” (UN FAO) Relative environmental impact of meat to soy protein production Environmentally relevant effect Land use Water requirement Fossil fuel requirement Phosphate requirement Emission of acidifying substances Emission of biocides Emission of copper Relative impact 6-17 4.4-26 6-20 7 >7 6 >100 Based on Table 1 of Reijnders and Soret, American Journal of Clinical Nutrition, 2003. Livestock and greenhouse gases • Livestock production is responsible for 18% of greenhouse gas emissions measured in CO2 equivalent (more than global transport), including • 9% of anthropogenic CO2 (largely as a result of deforestation) • 37% of anthropogenic methane (with 23 times the global warming potential of CO2) • 65% of anthropogenic nitrous oxide (with 296 times the global warming potential of CO2) • Livestock also account for 64% of anthropogenic ammonia, a significant contributor to acid rain and the acidification of ecosystems Diet and global warming A study by researchers at the University of Chicago compared the amount of fossil fuel needed to cultivate and process various foods, and factored in emissions of methane and nitrous oxide produced by livestock. The researchers found that the typical US diet, to which animal foods contribute about 28% of the energy intake, generates the equivalent of nearly 1.5 tonnes more carbon dioxide per person per year than producing the same amount of food energy from plant foods alone. In comparison, the difference in annual carbon dioxide emissions between driving a typical saloon car and the most energy-efficient car on the US market, based on average annual mileage figures, was just over one tonne. Methane and climate change • Methane is the most important non-CO2 greenhouse gas, responsible for nearly as much global warming as all other non-CO2 greenhouse gases combined • Human activities produce 1½ times as much methane as all natural sources combined (compared with just 3% for CO2) • Livestock rearing is the largest anthropogenic source of methane (37%) • Lower methane emissions quickly translate to a cooling of the Earth’s atmosphere because methane cycles out of the atmosphere in just 8 years (in contrast, CO2 can remain in the air for more than 100 years) • “Switching to a vegan diet is a faster way of reducing global warming than cutting CO2 emissions” (Earthsave International) Fish production • 132.5 million tons of seafood (fish, crustaceans, etc) was 'harvested' in 2003, equivalent to 21 kg per person, including 54.8 million tons (41%) from aquaculture (fish farms) • The collapse of all wild fisheries has been predicted by 2050 (collapse is defined as 90% depletion of stocks) • 1.2% of global oil production is used to catch wild fish • The energy used to obtain fish protein may be up to 14 times higher than for the same amount of plant protein Is aquaculture the answer? • Aquaculture is the fastest growing animal food producing sector • 3-4 kg of wild fish are required to produce 1 kg of farmed salmon • The chemicals used to keep farmed fish free of parasites and disease are a major source of environmental pollution • The environmental impacts of aquaculture may be of the same order of magnitude as conventional animal husbandry Evaluation of the environmental impacts of various diets using lifecycle assessment An Italian study* compared the overall environmental impact of 7 diets using lifecycle assessment, taking into account effects on human health, ecosystem quality and resource use. The diets were as follows: • NORM-INT a ‘normal’ Italian diet, equivalent to the average Italian weekly diet, with food from conventional farming • OMNIV-INT a prudent (low meat and fish) omnivorous diet based on food from conventional farming • OMNIV-BIO as above but based on food from organic farming • VEGET-INT a vegetarian diet based on food from conventional farming • VEGET-ORG as above but based on food from organic farming • VEGAN-INT a vegan diet based on food from conventional farming • VEGAN-BIO as above but based on food from organic farming * Baroni, Cenci, Tettamanti and Berati, European Journal of Clinical Nutrition, 2006. Average environmental impact (in points) of the 7 diet types 6 5 4 3 2 1 0 NORM-INT OMNIV-INT OMNIV-ORG VEGET-INT VEGET-ORG VEGAN-INT VEGAN-ORG Resources 3.7 1.415 0.798 0.878 0.594 0.544 0.455 Ecosystems Quality 0.65 0.268 0.265 0.167 0.177 0.112 0.0714 Human Health 1.06 0.458 0.2 0.335 0.18 0.15 0.0397 The study concluded that “vegetarian and vegan diets could play an important role in preserving environmental resources and in reducing hunger and malnutrition in poorer nations”. In defence of livestock Livestock provide a livelihood to 1.3 billion people (20% of world population), provide essential draught power, manure and fuel (dung, biogas) in developing countries, and can be reared on land unsuitable for crop production. Animal foods can make an important contribution to the diet of the under-nourished, and can have a lower environmental impact than plant foods (e.g. air-freighted plant foods or vegetables grown in heated greenhouses). Conventional solutions • Improve the resource use efficiency of livestock production • Price natural resources (land, water, etc) to reflect the full economic and environmental costs of livestock production • Remove damaging subsidies • Provide payment for environmental services • Develop the necessary institutional and policy frameworks Green solutions “Government policy should encourage vegetarian diets. Possible mechanisms include an environmental tax on meat, a shift in farm subsidies to encourage plant agriculture over animal agriculture, or an increased emphasis on vegetarian foods in government-run programmes.” Noam Mohr, Earthsave International “The production of meat and dairy products has a much bigger effect on climate change and other environmental impacts than that of most grains, pulses and outdoor fruit and vegetables. Many people could benefit from eating a larger proportion of fruit and vegetables and less saturated fat.” Buying food: greener choices, UK Government website What you can do • Eat fewer animal foods, or none at all • Buy locally produced, seasonal, organic food as far as possible • Grow your own fruit and vegetables, and gather edible wild foods • Compost your kitchen and garden waste • Cut down on car journeys for food shopping • Use tap water instead of bottled water • Avoid unnecessary packaging or choose biodegradable or recyclable packaging Sources and Resources • Livestock’s long shadow: environmental issues and options. UN Food and Agriculture Organisation, 2006. • Luciana Baroni et al. Evaluating the environmental impact of various dietary patterns combined with different food production systems. European Journal of Clinical Nutrition, 2006. • Lucas Reijnders & Sam Soret. Quantification of the environmental impact of different dietary protein choices. American Journal of Clinical Nutrition, 2003. • Gidon Eshel & Pamela Martin. Diet, energy, and global warming. Earth Interactions, 2006. • Noam Mohr. A New Global Warming Strategy. Earthsave International, 2005. • Mark Gold. The Global Benefits of Eating Less Meat. Compassion in World Farming Trust, 2004. www.eatlessmeat.org • www.direct.gov.uk/en/Environmentandgreenerliving/Greenerfoodanddrink/ (UK Government web site offering advice on ‘greening’ your diet) • www.earthday.net/footprint (Calculate your ecological footprint)