(Written by Anna Lappé1 for Sustainable Table)
In this section:
Taking a bite out of climate change
The food and climate change connection
Table 1: Main sources of emission from agriculture
On the farm
The livestock liability
On the land
On the road: the food miles question
Other sources of emissions How can farming help address the climate crisis?
What you can do
Table 2: An overview of food system sources of greenhouse gases
Table 3: The core difference between climate-crisis agriculture and climate-friendly farming
Visit Take a Bite out of Climate Change to learn more about the connection between our food system and climate change. Taking a Bite out of Climate Change
On September 8, 2008 Dr. Rajendra Pachauri, chair of the United Nations Intergovernmental Panel on Climate Change, spoke to 400 people gathered for an event hosted by the animal welfare organization, Compassion in World Farming.2 Pachauri, an Indian economist (and vegetarian) who had just been reelected to a second term as chairman, made one of the most public and bold statements about the connection between our diet and global warming on the world stage: Choosing to eat less meat, Pachauri said, or cutting out meat entirely, is one of the most important personal choices we can make to address climate change.
“In terms of immediacy of action and the feasibility of bringing about reductions in a short period of time, it clearly is the most attractive opportunity,” said Pachauri. “Give up meat for one day [a week] initially, and decrease it from there.”
To many of us, Pachauri’s specific prescription for addressing change might come as a surprise. When we think about the culprits behind the climate crisis, we tend to think about Big Oil or dirty coal-fired powered plants. We picture cars and industrial skylines, or imagine factories and smokestacks. It’s time we start thinking about another sector of the economy that is increasingly exacerbating the climate crisis. The global food system—including deforestation to make way for crops for cattle and cars—is responsible for an estimated one-third of total greenhouse gas emissions (see below, Main Sources of Emission from Agriculture).
Livestock production alone contributes to 18 percent of the global warming effect—more than the emissions from every single car, train, and plane on the planet.3 Though livestock production only contributes 9 percent of carbon dioxide emissions, the sector is responsible for 37 percent of methane and 65 percent of nitrous oxide, both potent greenhouse gases.4
Move over Hummer, say hello to the hamburger.
The Food and Climate Change Connection
So how is food—supposedly life-sustaining stuff—one of the key factors in an environmental crisis that threatens the basis of life on earth? A big part of the answer is in the rapid and radical twentieth-century transformation of our food system from sustainably based, locally focused production, to a fossil-fuel addicted industrialized system. Agriculture has changed more in than the past two generations than it did in the previous 12,000 years. Unfortunately for us, almost every single aspect of our modern industrial system creates greenhouse gas emissions. And, as Dr. Pachauri says, another big reason is the rapid growth of livestock production. Indeed, to produce 2.2 pounds of beef burns enough energy to light a 100 watt bulb for twenty days Pachauri noted in his remarks earlier this month.5
Table 1: Main Sources of Emission from Agriculture
Main Sources of Emissions Percent of the Total Global
Warming Effect of Emissions
On the Farm
Fertilizer production and distribution
Methane and nitrous oxide emissions
1.5 to 2%
On the Land
Deforestation and other land use changes
On the Road
Transportation emissions from seed to plate
Specific food-system data unavailable
Waste and manufacturing
Specific food-system data unavailable
Estimated Total6 33% of the total global warming effect can be attributed to the food system.
On the Farm
Fertilizers and On-Farm Fossil Fuel Use
Industrial farms are fossil-fuel addicted places, from their reliance on fossil fuels for powering machinery to petroleum-based chemicals used to create artificial soil fertility, protect against pests, and stave off weeds. The use of fossil fuels on farms, as well as in the manufacture of fertilizers and agricultural chemicals, contributes to the emissions of the food sector.
With one-third of the world’s cereal harvest and 90 percent of the world’s soy harvest being raised for animal feed, the energy required to grow those crops is a major factor in these on-farm emissions.7 In the United States and Canada, half of all synthetic fertilizer is used for feed crops.8 In the UK, the total is nearly 70 percent.9
A major reason that beef, in particular, has such a large environmental impact is because, of all livestock, cattle are among the worst converters of grain to meat. Whereas in nature cattle, which are ruminants, convert inedible-to-humans grasses into high-grade proteins, under industrial production grainfed cattle only provide about 1 pound of beef for every 10 to 16 pounds of feed they consume.10
Because industrialized agriculture also relies on huge amounts of water for irrigation, these farms will be much more vulnerable as climate change increases extreme droughts. Globally, 70 percent of the world’s available freshwater is being diverted to irrigation-intensive agriculture.11
The Livestock Liability
The other reason that livestock production has such a big impact on climate change is because livestock are among the main sources of the world’s methane emissions. (Rice cultivation is another. According to the Stern Report, rice cultivation emits one-tenth of agricultural emissions.12) Ruminant livestock, including cattle, buffalo, sheep, and goats, are the main agricultural sources of methane. They can’t help it; it’s in their nature. Ruminants digest through microbial, or “enteric” fermentation, which produces methane that is then released by the animals through belching and, to a lesser degree via their, er, tailpipes. While this process enables ruminants to digest fibrous grasses that we humans can’t convert into digestible form, it also contributes to livestock’s climate change toll. Enteric fermentation accounts for one-quarter of the total emissions from the livestock sector. (Land use changes, such as deforestation and desertification caused by over-pasturing livestock or growing feed crops, account for another 35.4%, while manure accounts for 30.5%).13
There’s another problem with industrial livestock: what happens with the waste. Now, in sustainable systems tapping into nature’s wisdom, there is no such thing as waste: manure is part of a holistic cycle; it’s fertilizer. But in confined animal feeding operations (CAFOs), this waste is not cycled through the farm, there’s too much of it. Instead, waste is stored in manure “lagoons,” as they’re euphemistically called. Without sufficient oxygenation, waste ends up emitting methane and nitrous oxide. The United States scores at the top of the world for methane emissions from manure, and pigs are at top in terms of methane emissions, responsible for half of the globe’s total.14
The sheer number of animals being raised for meat on the planet is another reason livestock production accounts for nearly one-fifth of all the globe’s greenhouse gas emissions. In 1965, 10 billion livestock animals were slaughtered each year; today that number is 55 billion. 15
On the Land
The bulk of the pressure on land around the globe, from precious wetlands in Indonesia to rainforests in Brazil, comes from the agricultural sector.16 These rainforests and wetlands play a vital role in climate stability because they sequester carbon, absorbing and storing carbon dioxide from the atmosphere in the soils and plants. With their destruction, carbon is released back into the atmosphere and the carbon cycle that keeps our climate in balance comes further unhinged. Because these lands play such a vital role as carbon sinks, it’s no surprise that their destruction is partly responsible for the emissions from land use changes that add up to nearly 18 percent of the total global warming effect.
The biggest driver behind these “land use changes,” as the climate change folks call them, is the expansion of pasture for cattle, feed crops for livestock, and oil palm for processed foods and biofuels.17 Most of these land use changes are concentrated in just a handful of countries. Brazil is the heart of rainforest destruction, mainly to meet demand for livestock grazing and feed. Malaysia and Indonesia are the world’s main producers of oil palm production, where plantations are leading to rapid rainforest and wetland habitat destruction. Malaysia produced 43 percent and Indonesia 44 percent of the world’s total palm oil last year.18 While data on the exact amount of land that has been converted into oil palm plantations is hard to come by, we know that demand for palm oil has soared in the last two decades, especially because of growing demand for edible vegetable oils from the world’s top two importing countries, India and China, according to an assessment by the USDA’s Foreign Agricultural Service.19
The erosion and deterioration of soils on industrial farms also releases greenhouse gases into the atmosphere. By destroying the natural soil fertility, and disturbing the soil through tillage, industrial farming also adds to the deterioration of soil and its carbon emissions.20
On the Road: The Food Miles Question
And what about the distance food travels to get to our plates? Despite all the attention to food miles, emissions from food transport are not the biggest culprit behind the sector’s impact on climate change.
While total emissions from transportation contribute to 13.1 percent of the global warming effect, this includes emissions from toting around all kinds of things—from people to pork chops.21 Transport emissions specifically from food are just a sliver of these emissions.
So why do food miles matter? Even though transportation isn’t the main source of our morsels’ emissions, reducing our food miles does make a dent in our dinner’s emissions toll. Consider the fossil fuels wasted carting fresh tomatoes to New Jersey, a state with ample farmland that exports tons of tomatoes every year. Researchers at Rutgers University estimated that meeting the New Jersey demand for just one year’s supply of out-of-state tomatoes for the state used up enough fossil fuel to drive an 18-wheeler around the world 249 times. 22
Food miles matter because so much of our food transport is unnecessary. Local food is also a better choice because it is fresher and therefore healthier for our bodies. Buying local also supports our local economies. Purchasing local foods means supporting small-scale businesses and protecting green space in our communities.
Of course, direct trade with small-scale farmers in far away places can be a critical way to support economic development half-way around the world. But most of the global food trade isn’t benefiting small-scale farmers, it’s benefiting the biggest grain traders, at the cost of the climate.23 And most of this global food trade is completely unnecessary, or redundant. Consider, for example, the fish caught off the coast of Maine, flash frozen, shipped to China for processing into filets, and shipped back to our mega-markets in the United States. Or, consider the business of beef. In 2007, the United States exported one 1.431 billion pounds of beef and veal (5.4 percent of our total beef production)24 and imported 3.052 billion pounds of the same, measured by commercial carcass weight.25 This cross-continent transport of food makes economic sense only because the true costs of such transport, including the big bill for its contribution to climate change, are not counted on the balance sheets of food corporations.
The main reason for sticking with the locavores is that the local food being celebrated is often a pseudonym for sustainably raised foods—and those foods will be the ones produced without the fertilizers, grown without destroying precious wetlands or rainforests, and with animals raised on pasture, not in confinement.
Other Sources of Emissions
Because the food system is connected to so many aspects of our lives, it’s hard to get an exact accounting of total emissions. Here are some other places where the food system’s emissions crop up.
Waste: Another 4 percent of global greenhouse gas emissions comes from waste, including food waste. Where does all our uneaten food end up and the tons of food ready for harvest that never even makes it to our plates? Landfills. And landfills are a key source of methane as food and other refuse decay.
Manufacturing: A further 10 percent of global emissions stems from manufacturing and construction, which includes construction for the food industry.
How Can Farming Help Address the Climate Crisis?
In nature, plants transform the sun’s energy into food that provides a foundation for life. We humans are fueled by this transformation either directly (we eat the food) or indirectly (we eat the animals that have fed on this energy). It’s a clever cycle: it’s inherently abundant. But the industrialization of agriculture, picking up pace in the past generation, has flipped the natural abundance of farming on its head. Instead of producing energy, industrial agriculture consumes it, through the addiction to fossil fuel-powered machinery and petroleum-based agrochemicals. Industrial farms are often considered highly efficient, but only because these wasted inputs and devastating outputs—including the impact on climate change—are not accounted for. (See Table 3: The Core Differences between Climate-Crisis Agriculture and Climate-Friendly Farming).
Unlike industrial farms, small-scale organic and sustainable farms rely on people power, not heavy machinery, and depend on nature, not manmade chemicals for soil fertility and to handle pests. As a result, small-scale sustainable farms have been found to emit between one-half and two-thirds less carbon dioxide for every acre of production. 26
New research is documenting that organic farms can emit as much as half the carbon dioxide as chemical farms. Organic farms also use much less fossil fuel energy than their conventional counterparts, in many cases as much as one-third less, and studies are also showing that organic farming can sequester carbon, providing a potentially powerful tool to help us address climate change. In fact, 10,000 medium-sized organic farms can store as much carbon in the soil as we would save if we took one million cars off the road.27
Yes, the very source of energy—the food consumers eat—has become one of the planet’s worst contributors to climate instability, but it need not be. There is another way.
What You Can Do
Eat and Drink with the Environment in Mind
Many of the resources at Sustainable Table can help you make climate-friendly food choices every day. Here are some of the principles of low-carbon dining, with links to more information.
Eat less meat and dairy: Go cold turkey, or just trim your consumption. Try cutting out meat just one day of the week. Check out Meatless Monday for more inspiration.
Choose organic and sustainably raised foods: Visit the Eat Well Guide to find local food near your home.
Eat local: Lower your food mile odometer, and always try to look for local sustainable food. Get inspired with these ideas and by the original locavores.
Eat whole foods: Cut back on processed foods—visit the Sustainable Kitchen for recipes and cooking ideas. Check out your “carbon foodprint” at Bon Appetit’s Low-Carbon Diet Calculator.
Take back the tap: Kick the bottled water habit. Visit Food & Water Watch for more information about the environmental impact of bottled water, the benefits of tap water, and how you can add your voice to those of people across the country demanding better regulation of our precious public resource—water.
Get Involved on a Broader Scale
Go beyond your plate to get involved with exciting campaigns that are making the food and climate connection. Here are three recommendations.
Rainforest Action Network’s Agribusiness Campaign
Join Rainforest Action Network’s agribusiness campaign and learn what you can do to help stop the deforestation of the world’s precious rainforests.
Center for Food Safety’s Cool Foods Campaign
Check out the Center’s newest campaign, helping eaters and businesses around the country learn about the simple choices they can make to support a climate-friendly food system.
La Via Campesina’s Small Farmers Cooling the Planet
Join with this international network of farmer associations across the planet to promote small-scale farming as a key strategy for mitigating and adapting to climate change.
Visit Take a Bite out of Climate Change to get more resources and sign up to stay informed.
Learn more about the meat and climate change connection. Read the definitive study from the United Nations: Livestock’s Long Shadow.
Check out the manifesto on Food and Climate Change from Vandana Shiva and her colleagues at the International Commission on the Future of Food. The Manifesto summarizes the connections between industrial agriculture and climate change and offers a compelling call to action from the perspective of farmers in the global south.
Read Soil not Oil by Vandana Shiva from South End Press: Shiva connects the dots between the world’s most pressing crises—food insecurity, oil dependence and climate change.
Created September 2008; Adapted from a forthcoming book on food and climate change by Anna Lappé. To find out more, visit: Take a Bite out of Climate Change
This is a working document. New studies about climate change and agriculture are continually being published. If you have any additions, suggestions, comments, or corrections, please contact the author at email@example.com.
Table 2: An Overview of Food System Sources of Greenhouse Gases
Gas What’s Food Got to Do With It? Global Warming
a summary of causes Potential
relative to carbon dioxide
Carbon Dioxide Carbon dioxide is emitted by burning fossil fuels to power farm machinery, produce agricultural chemicals, and transport food. In addition, carbon dioxide is released when forests and wetlands are cleared for crop production, particularly for animal feed, pasture, or oil palm production. Finally, trapped carbon in soils is also released through soil erosion and deterioration on industrial farms. —
Methane* Agricultural methane is released primarily by ruminants, such as cattle, and during rice production. 23 times the greenhouse effect of carbon dioxide over 100 years. 62 times over 20 years.28
Oxide* Nitrous oxide is released mainly from the use of man-made fertilizer, especially the overuse of nitrogen on crops grown for animal feed. 296 times the greenhouse effect of carbon dioxide over 100 years. 275 over 20 years.29
*A note about methane and nitrous oxide: In the U.S., the food system accounts for an estimated 17 percent of all fossil fuel use, but accounts for a much larger percentage of our country’s methane and nitrous oxide emissions. Widespread overuse of artificial nitrogen fertilizer, for instance, much of which is wasted in leaching and runoff, contributes to three-quarters of our country’s nitrous oxide emissions. And globally, agriculture is responsible for nearly two-thirds of methane emissions. While methane and nitrous oxide make up much smaller portions of total greenhouse gas emissions, these gases are still important factors in the climate crisis, in part because they each have stronger global warming effects than carbon dioxide and also because they are an increasing portion of total emissions.
Table 3: The Core Differences Between Climate-Crisis Agriculture and Climate-Friendly Farming
Climate-Crisis Agriculture Climate-Friendly Farming
Ignores Place Values Place
Emits Carbon Stores Carbon
Dependent on Chemicals Depends on Nature for Fertility and Pest Management
Disrupts Natural Cycles Protects Nature’s Cycles
Squanders Energy Produces Energy
Fossil-Fuel Powered People and Animal Powered
Wastes Water Retains and Conserves Water
Eldredge, N. (2002). Life on Earth: An Encyclopedia of Biodiversity, Ecology, and Evolution. Santa Barbara, Calif., ABC-CLIO.
IPCC (2007). Climate Change 2007: Fourth Assessment Report of the Intergovernmental Panel on Climate Change. New York, Cambridge University Press.
Lappé, F. M. (1991). Diet for a Small Planet. New York, Ballantine Books.
McMichael, J., J. Powles, et al. (2007). “Food, Livestock Production, Energy, Climate Change, and Health.” The Lancet 370: 1253-1263.
Roberts, P. (2008). The End of Food. Boston, Houghton Mifflin Company.
Steinfeld, H., P. Gerber, et al. (2006). Livestock’s Long Shadow: Environmental Issues and Options. Rome, Food and Agriculture Organization of the United Nations.
Stern, N. H. and Great Britain. Treasury. (2007). The Economics of Climate Change: The Stern Review. Cambridge, UK ; New York, Cambridge University Press.
Weis, A. (2007). The Global Food Economy: The Battle for the Future of Farming. London, Zed Books.
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