carbon footprints

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CHAPTER 4: THE CARBON FOOTPRINT CONTROVERSY

What is the carbon footprint controversy?

Nearly all humans consume meat, dairy, and egg products in some form. In recent years the e i me al m eme ha ed he ece i f ed ci g e ca b f i . Ca e reduce our footprint without changing our diet? Much controversy surrounds that question. One very extreme view on the political-left is below.

But when it comes to bad for the environment, nothing literally compares with eating meat. The business of raising animals for food causes about 40 percent more global warming than all cars, trucks, and planes combined. If you care about the planet, it's actually better to eat a salad in a Hummer than a cheeseburger in a Prius.

Bill Maher, host of HBO talk show Real Time with Bill Maher, writing in the Huffington Post in 2009. Accessed April 25, 2013 at http://www.huffingtonpost.com/bill-maher/new-rule-a-hole-in-one-sh_b_259281.html.

The last decade has seen a movement advocating a vegan diet in order to reduce carbon emissions, and in some respects the argument is logical. After all, it takes about 3.388 lbs of corn (and many other inputs) to produce a single pound of retail beef, making meat seem relatively inefficient to grains, thus leading to a larger carbon footprint.134 So common is this notion that some schools e c age Mea le M da for the sake of the environment. The Meatless Monday movement has even been adopted by the Norwegian military.135 Moreover, there is some scientific research showing that vegan (and vegetarian) diets do result in a smaller carbon footprint.136

When dealing with issues as big as global warming i ea feel hel le , like he e li le e ca d make a diffe e ce B he mall cha ge e make e e da ca ha e a eme d im ac . Tha h his Meatless Monday resolution is important. Together we can better our health, the animals and the environment, one plate at a time.

Los Angeles Councilmember Ed Reyes, co-author of a Meatless Monday resolution in 2012.137

However, equally prestigious research shows that vegan diets can result in a higher carbon footprint.138 How can this be? One reason is that some carbon footprint estimates are wrong, or rather, interpreted incorrectly. The idea of livestock production being a large carbon emitter began with a report by the United Nations (UN) suggesting that livestock contributes 18% f he ld carbon footprint, more than the transportation sector,139 thus giving Bill Maher reason to point the blame at burgers instead of Hummers.

It turns out that this 18% is fraught with errors, a lea , d e e e e c di i i he U.S. For instance, the UN did not account for the carbon emissions involved in making the inputs used in the transportation sector, but they did for livestock. This would be like saying the production of tires has zero carbon emissions but the production of corn does. Also, that 18% makes a number of contestable assumptions, especially regarding how land use changes as livestock production rises.140 Finally, the study was meant to be an estimate for world emissions whereas people like Maher were interpreting it as relevant to U.S. emissions. Correcting these mistakes for the U.S. shows that livestock is responsible for only about 3% f Ame ica ca b f i ,141 whereas transportation counts for 26%.142 All of agriculture impacts only 6-8% of the American footprint143 (note that these numbers only refer to carbon emissions that are the result of human activity, not emissions occurring naturally).

Much happens with food between farm and fork, and carbon is emitted there also. Only 20% of the cost of food reflects farm activity. The other 80% reflects the cost of labor, energy, machinery, and other activities at the food processing and retail level.144 A food item might generate few carbon

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emissions at the farm but large emissions at the processing level, so a vegan diet might not be light on carbon if it undergoes considerable processing. One must also account for the amount of food eaten. Although 3.388 lbs of corn may be needed to produce one pound of retail beef, that pound of beef has more calories.145

To determine the relationship between diet and carbon footprints the best studies examine the actual foods that vegans, vegetarians, and omnivores consume. Because these studies do not agree, a controversy exists.

The crux of the debate has moved beyond the question of vegetable versus meat diets, and instead attempts to find out the types of food which provide the most satisfaction with the smallest carbon footprint. This chapter will compare the carbon footprint of organic to non-organic food, beef to chicken, grass-fed to corn-fed beef, and the relationship between carbon emissions and the price of food.

The eade migh de h e ha e me i ed he c e f gl bal warming itself, given the torrid rhetoric between global warming denialists and alarmists. Because we are not climate scientists we will say very little about how agricultural activities affect future temperatures. We do assert two statements as facts though. One is that gases like carbon dioxide and methane are greenhouse gases that retain heat. After all, Venus is much hotter than Mercury despite being further from the sun, simply because the atmosphere of Venus c ai g ee h e ga e a d Me c d e . The ec d fac i ha , beca e me ac i i ie ake g ee h e ga e f m he ea h crust and eject it into the atmosphere, there is some probability that the use of fossil fuels will have a noticeable change in the climate within the next 100 years. We make no assertion as to what that probability is, only that it is greater than zero. This chapter focuses on how food affects emissions of greenhouse gases, not on how those emissions affect the climate.

Th gh hi cha e e ill be efe i g ca b he e a e eall c ce ed ab all g ee h e ga e , a d ca b eall efe ca b di ide e i ale emi i denoted CO2e. One ton of methane results in 21 times the warming of one ton of carbon dioxide, so if a ton of methane is emitted we instead say that 21 tons of ca b emissions (20 tons of CO2e) take place. To repeat, when we say one ton of carbon, we are always referring to one ton of CO2e.

How does agriculture contribute to greenhouse gas emissions?

I he 1920 , he R ia novelist Yevgeny Zamyatin wrote his science fiction dystopia, We, he imagined food being produced directly from petroleum. His vision was prescient. Plants may acquire their energy from the sun but farmers acquire it from fossil fuels. Obviously, tractor fuel is based on petroleum, but so is nitrogen fertilizer. Other fertilizers like phosphorus and potassium require mining, using the brute force of oil-powered machinery to dig deep into the earth. Pesticides require fossil fuels, so do irrigation equipment, milking machines, etc. Even if organic farmers use manure as fertilizer they still rely upon on fossil fuels, and not just to power machinery. Often they acquire this manure from livestock on non-organic farms, and those livestock were fed forage and grain fertilized by chemicals which were created using fossil fuels.146

I efe he g ea T H d ed Yea Wa , he a be ee he ci a d he la d. P babl acc f eligi prejudices, the imi i e ea a bb l held hei b ead. I he hi -fifth year before the foundation of the One State our contemporary pertroleum food was invented.

Zamyatin, Yevgeny. 1924. We. Momentum: Australia.

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Since most of the new carbon ejected into the atmosphere comes from fossil fuels, the carbon footprint of food can be reduced by using less oil, coal, and natural gas. Because these fuels are expensive, farmers and food manufacturers have always been in the game of conserving energy, and have done so mostly by increasing their productivity. As technology has evolved over time to reduce energy costs, the carbon footprint of food has likewise fallen. 147

There is more to a carbon footprint than energy use. One reason beef has a larger footprint than pork or chicken148 is because cattle are ruminants, and ruminants expel carbon as they burp and they burp about once a minute.149 A wheat farmer who plows his soil might emit more carbon than a wheat farmer using no-till methods, as breaking and turning the soil releases carbon into the atmosphere.

The carbon footprint of food even depends on consumer behavior. It takes more gasoline to drive to the grocery store and to the farmers market, and consequently, more carbon emissions. The relationship between food and carbon does not depend solely on how food is produced, but also how it is purchased.

Does organic food have a lower carbon footprint?

It depends. Carbon emissions are influenced by the type of nitrogen fertilizer a farm uses.150 Organic advocates are quick to point out that they do not use chemical nitrogen fertilizer, and thereby avoid one large source of carbon emissions.151 Many organic farmers acquire their fertilizer from livestock manure though, and many of these animals were fed forage that was fertilized with chemical fertilizers.152 If this is the norm, then organic farmers are reliant on chemical fertilizers but are using it in a very inefficient manner that might increase the carbon footprint of their food. Manure and human compost two sources of organic manure both emit carbon as they are stored, and these emission rates are rather large.153

An advantage of organic fertilizer is its ability to sequester carbon in the soil. Fertilizing a field with manure, compost, or cover c d e j add he three key nutrients of nitrogen, phosphorus, and potassium, but increases the carbon content of the soil. Such fertilizers are not strictly reserved for organic production though, and there are many farms raising conventional crops using livestock manure. Still, most conventional farms do not use organic fertilizer, while all organic farms do. If a heavily farmed field low in organic matter is converted to organic production, carbon will be extracted from the atmosphere and stored in the soil, thereby reducing the carbon footprint of organic food.154 The rate at which carbon is sequestered in the soil is highly uncertain though, and causes considerable uncertainty in carbon footprint measurements.

Although organic producers may argue otherwise, organic farming is less productive (this is discussed in detail in another chapter). Organic farmers, by definition, have a smaller number of farming options to choose from than conventional farmers. In fact, if organic really were more productive, there is nothing stopping conventional farmers from using organic methods, but the fact that conventional farmers choose other technologies suggests organic methods are less productive.

Higher productivity means it takes fewer inputs to produce any given unit of output, and less inputs typically means less carbon emissions per unit. However, a i i a i gle hi g, a d e e if a farmer spends less money on all inputs, ha d e mea he ca b emi i f m h e i will fall, if the portfolio of inputs changes in favor of high carbon emitters. For these and other

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reasons, the question of whether organic food has a smaller carbon footprint is an empirical question, requiring data for an answer.

The data do not crown either organic or conventional as king. Sometimes organic food has smaller emissions and sometimes it does not. One study comparing organic and conventional production of twelve crops (blueberries, two kinds of apples, two kinds of wine grapes, raisins, strawberries, alfalfa for hay, almonds, walnuts, broccoli, and lettuce) found that conventional production usually had a smaller footprint, assuming the land has been used in the same way for many years. However, if the organic farm is rather new, and its fields were heavily plowed in the past, the soil may be sequestering enough carbon to make organic produce the low-carbon emitter.155

Similar results were found for hogs. Conventional hog production appears to emit less carbon when soil sequestration of carbon is ignored, but when it is accounted for, organic pork systems might or might not emit less carbon.156 Beef will be discussed in its own section, and it will be shown that unless carbon sequestration of pasture is much higher than current measurements, organic beef results in a larger carbon footprint.157

There is insufficient evidence available to state that organic agriculture overall would have less of an environmental impact than conventional agriculture. In particular, from the data we have identified, organic agriculture poses its own environmental problems in the production of some foods, either in terms of nutrient release to water or in terms of climate-change burdens. There is no clear-c a e he e i : hich lle ha a l e e i me al im ac - the organic one or the conventional one?

Foster, C., K. Green, M. Bleda, P. Dewick, B. Evans, A. Flynn, and J. Mylan. 2006. Environmental Impacts of Food Production and Consumption: A report to the Department for Environment, Food and Rural Affairs. Manchester Business School. Defra, London. Page 14. A French study compared fifteen different foods and found organic versions of the food to have a lower footprint in only five cases.158 There appears no noticeable increase or decline in carbon emissions from switching from conventional to organic milk production.159 When comparing meat products in the UK, organic production resulted in lower emissions for sheep and pork, but higher emissions for beef and poultry.160

The frustrating thing about evaluating the carbon footprint of organic and non-organic food is the blatant biases of sources. For instance, the Environmental Working Group published a figure showing the carbon footprint of various foods, including fruits, vegetables, meat, dairy, and eggs. They communicate the idea that chicken meat is the best meat in terms of carbon, but then they added the qualification that this chicken should be organic, pasture-raised, and/or antibiotic-free whenever available.161 This suggests that organic chicken emits less carbon than conventional chicke , b he e he ci e d e d a ga ic f d , a d ce ai l d e c m a e organic to non-organic food. It is clear that this source took the results from [what appears to us to be] a credible study and then added some of their own beliefs (which cannot be defended by data), making it seem as if that credible study deemed organic foods to be environmentally friendly.162

The agricultural industry is also to blame for misleading readers. The agribusiness newspaper Feedstuffs has published a number of articles making it seem that organic food always has a higher carbon footprint,163 yet, research contradicts such blanket conclusions.

Often it seems groups decide first which foods emit less carbon and then seek out the data defending their choice, rather than letting the data determine their conclusions. This way of thinking detaches a controversy from evidence, making resolution impossible.

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How do animal- and plant-based foods compare?

Two studies have been conducted to answer this question by studying the actual foods vegans, vegetarians, and omnivores tend to eat. One study took place in the UK and one in France, and they yield conflicting results. The UK study found that the foods vegetarians and vegans eat result in less carbon emissions.164 The French study found that, on a per calorie basis, fruits and vegetables had a similar carbon footprint to animal-based foods (except meat produced from ruminants like cows and sheep, whose emissions were larger). While animal-based foods emitted more carbon on a per pound basis, one generally needs more pounds of fruits and vegetables to provide the same number of calories, and so they concluded that vegan and vegetarian diets do not have lower carbon footprints.165

Suppose the UK study is right and vegan diets do emit less carbon. Vegan meals are also less expensive, according to this study, and if those savings are spent on things that are high emitters of carbon (like a plane flight) they may negate any emission reductions attributable to the vegan diet directly.166 The im ac f e die e e de e d he e e i l ca ed. Th e l ca ed cl e fertile land, where fruits and vegetables can be produced in ample quantities, may be able to lower their footprint by eating a vegan diet. Contrary, an omnivorous diet with moderate amounts of meat emits the least carbon in areas with poor soil, where grass for livestock may be the only good use for the land. Why? Because efficient food production requires putting agricultural lands to their best use.167 It is best to grow tomatoes in southern California and beef in Montana.

How do beef, pork, eggs, and poultry compare?

Hogs and birds in livestock production can convert feed to meat more efficiently than cattle. They also reproduce faster. Cattle grow and reproduce slower, and, being ruminants, emit greenhouse gases as they burp. For these reasons the carbon footprint for beef is about three times the size of pork and turkey, four times the size of chicken, and six times the size of eggs (all on a per lb basis). The magnitudes differ across studies but there is little debate that beef has the largest footprint, followed by pork, then chicken, then eggs.168

Should we feed cows grass or corn?

Reade ma ha e ee he label g a -fed beef a ecial e fa me ma ke s. This is a certified USDA label that beef producers can earn so long as they feed cattle only forage (grass and hay) throughout ca le life and always provide them access to pasture during the growing season.169 The label may be slightly misleading, as all cattle spend a large part of their lives on pasture, even if they are not sold as grass-fed beef.170 The difference comes in the last four to six months of the c life, where most cattle enter a feedlot and are given a diet consisting mostly of grain (usually corn and soybean meal). Grass-fed beef do not enter a feedlot, but remain on pasture whenever grass is growing. It would be more transparent to call one type of beef c -fi i hed a d he other g a -fi i hed beef, b ha i he e mi l g ha ha e l ed.

Consumers naturally want to know whether grass-fed or corn-fed beef has a smaller footprint, but there is no easy answer. The documentary Carbon Nation argues that one of the most effective means for reducing greenhouse gases in the atmosphere is to encourage permanent pastures for grazing.171 The film di ec a d d ce Pe e B ck passionately argues this can be accomplished by allowing cattle to remain on grass throughout their lives.172

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Plants, with the help of fungi that live on their roots, naturally capture carbon from the atmosphere and store it in the soil, but modern cropping methods tend to disrupt this soil and kill these fungi, releasing the carbon back into the air. Converting fields that formerly grew corn for the feedlot to pastures, Carbon Nation argues, can reduce our carbon emissions by 39%. While the film cautions ha N hi i e cie ce, be e, it follows b a i g b he early numbers are

e c agi g.

The viewer of Carbon Nation or any interview with Peter Byck, might be quickly convinced that by replacing their regular beef with grass-fed beef, they are doing their part for the planet without giving up the foods they love. If that same viewer then turned the channel from Carbon Nation to the talk-show Stossel, they might then see the animal scientist Jude Capper argue otherwise.173

[Grass-fed cattle] have a far l e efficie c The animals take 23 months to grow versus 15 [for corn-fed cattle]. Tha a e a eigh m h f feed, f a e , la d e b i l , a d a a f l l f a e. If e ha e a g a -fed animal compared to a corn-fed animal, ha like addi g alm e ca he ad f e e i gle a imal. Tha a h ge increase in carbon footprint.

Capper, Jude [interviewee]. Ma 6, 2011. Wh G a -Fed Beef I W e f E i me . Stossel [television show] Fox Business Video. Stossel, John [interviewer].174 Capper and her colleagues have published studies in the peer-reviewed scientific literature showing that grass-fed, ga ic, a d m a al beef d c i em ha e a higher carbon footprint than conventional beef. Feedlots simply produce beef more efficiently than forage systems. By using fewer inputs to produce a pound of beef, less fossil fuels are required to produce those inputs, and on a per pound basis the carbon footprint for corn-fed beef is smaller. Moreover, it takes longer to fi i h g ass-fed cattle, which means the cow has to live longer to produce the same amount of beef, and during that time the cow constantly expels methane. Capper reports that a conventional beef production system requires only 56% of the animals needed to produce the same amount of beef as a grass-fed system, only 25% of the water, 55% of the land, and 71% of the fossil fuels. Because it is less efficient, the carbon footprint for grass-fed beef is 68% higher than that of corn-fed beef, Capper calculates.175

So, who is correct: Byck or Capper? It depends on the rate at which the extra pasture needed for producing grass-fed beef can sequester carbon. Although sequestration numbers are highly sensitive to environmental conditions, most of the measurements suggest Capper is correct and that grass-fed beef would actually increase the carbon footprint of a steak.

Byck is then correct only if his optimistic assumptions about the ability of soil to sequester carbon are correct. Carbon Nation is absolutely right that plant growth can sequester carbon in the soil, and the transition of land out of heavily-plowed cropland into pasture for cattle could (again, under

imi ic a m i ) deli e e gh ed c i e e e Ca e fi di g .176 Once that transition is complete and the land reaches a new equilibrium of carbon in the soil, then carbon sequestration ceases and the smaller carbon footprint then belongs to corn-fed beef.177 This suggests that any advantage grass-fed beef may have is either unlikely or fleeting.

So for now, corn-fed beef seems to have a smaller impact on global warming, but the science on this issue is young. Measuring carbon footprints requires many assumptions that are difficult to verify, and small changes in those assumptions can have sizeable impacts. Thus, other studies attempting to measure carbon footprints could arrive at different conclusions. Much more research on this topic is

eeded, i cl di g e lica i a d e e i f Ca e k.

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How can I lower my carbon footprint from the food I eat?

Meatpacking in nineteenth century Chicago was a brutal, dirty business. It was a time when companies could dump waste into rivers without criticism. Gustavus Swift erected large meatpacking plants in Chicago where livestock were slaughtered and then shipped to New England by rail. He did not care about the purity of the local rivers, yet his polished business skills contributed remarkably to reducing water pollution.

Swift did make m e f m hi ale f beef. His profits were in the by-products from beef production, like fat turned into soap, hides processed into leather, guts into tennis racket strings, and hair into stuffed cushions. The few parts of the carcass that were discarded left the plant in sewer pipes and flowed into Bubbly Creek, which then flowed into the river. Any amount of fat, gut, or hair that escaped the plant and flowed into the creek was money lost to Swift, so he would wade into the water to watch what came out of the sewer. Any fat escaping the pipe was a clear sign that his factories operated inefficiently, so he would trace the source of the leakage and fix it. He despised pollution, not because he loved the environment, but because he loved money. By pursuing his own self-interest he reduced the amount of pollution entering the river.178

Why tell this story? Because we often ignore the fact that people everyday reduce pollution without any intention of doing so, simply by producing things efficiently. The road to hell is paved with good intentions, the saying goes, so perhaps the road to heaven is built on self-interest? Every business that operates more efficiently than its rival reduces the carbon footprint of that product. Most people assume organic food is good for the environment because its proponents boast of their green intentions. Sometimes this is indeed the case. Yet sometimes non-organic food has a smaller carbon footprint because it is produced more efficiently. Like Gustavus Swift, conventional producers look for every source of waste, and when they fix that waste they are able to produce each unit using less energy. Less energy then translates into less carbon. When the beef industry started giving calves growth hormones to help them grow faster they were not trying to reduce the carbon footprint of beef, but that is exactly what they did.179

If the reader really cares about the environment then they will concentrate on the actual level of carbon emissions and not just rely on the stated intentions of the seller. What matters are outcomes, and if an industry exhibits no sincere concern for the environment but leaves behind a smaller carbon footprint, they provide a public good.

As a general rule, the more a product costs the larger i ca b f i . Thi i al a he ca e, but adding value to a product or service usually requires more energy, and most of the time that energy is derived from fossil fuels, which have carbon footprints of their own. This means that any time a person wants a higher valued product sold at a higher price she will probably leave a larger carbon footprint. Thi k back he ca b f i f a i mea , he e beef f i a larger than chicken. It is also true that the price of chicke i c ide abl le . Y d ha e gather research behind each food item to lower your carbon footprint prices already reveal a wealth of information.

Consider this example. A mug of coffee emits 23 grams of CO2e (carbon dioxide equivalent). Add milk, and that milk must be produced from cows that emit greenhouse gases, eat corn that was produced using fertilizers made out of fossil fuels, and produce milk that must be transported by truck and kept cold in refrigerators. With milk, the coffee now emits 55-74 g CO2. Cappuccinos

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entail even more activities, where the milk must be steamed, increasing the emissions to 236 g CO2e. At each step, as the product increases in value and price by requiring more inputs, more greenhouse gases are emitted.180

One step to reducing your footprint is to purchase less costly food. Instead of getting a cappuccino, just get a regular cup of coffee. The regular coffee also saved you money, though, and you want to make sure those savings are not spent in a way to increase emissions, so you would then take those savings and purchase carbon offsets (where you pay others to emit less carbon). The same goes for other foods. Instead of going vegan, where you might begin eating at expensive vegan restaurants whose footprint might be large, consider eating a more austere meal occasionally. Instead of purchasing grass-fed beef, consider purchasing regular, less expensive meat. Then be careful not to use the savings on yourself, but buy carbon offsets instead.

Purchasing carbon offsets is easy, even for an individual with just a little money. A simple Google search will reveal many organizations like CarbonFund.org, where individuals pay money to prevent deforestation, restore forests, encourage renewable energy production, and retire carbon permits. These are activities to which you can direct your savings from an austere diet. In fact, the average

e ca b f i i ab 24 181 of carbon per year, and at the CarbonFund.org website one can offset 24 tons for only $240. This means that if you are truly concerned about global warming but want to continue eating the same types of food, and consume other goods in the same proportion as before, for only $240 a year one can shrink their carbon footprint to zero!

Thi d e mea should not a a e i claim made ab a d c f i . Nor are we suggesti g ha ig e a f d i i al c e , cal ie , he e i me al im ac in addition to global warming. What we are trying to stress is that, in addition to all the environmental and health claims associated with a food, one should also incorporate information on he d c ice in guessing its carbon footprint.

These are guidelines you can extend to every good you buy, not just food, and the goal is not just to reduce carbon emissions but to achieve that reduction by giving up the goods you value the least. Beef may have a larger footprint than chicken, but for many it is the most delicious meat, and they would rather reduce their carbon emissions by giving up anything other than beef. Evidence suggests that maintaining attractive lawns by chemical applications and regular mowing can cause the emission of more carbon per acre than that devoted to corn.182 A reader may decide to spend a lot less money on lawn fertilizer and eat the same foods.

Some readers may have begun this chapter believing they would know exactly what foods to eat by the end, but now they feel even more confused than ever. Such readers should take pride in this confusion, because it is the direct result of truly understanding the carbon footprint controversy. Yes, deciding what foods to eat can be a frustrating task these days, but we should be grateful for this frustration, for it means that we are more educated about food and we are blessed with the freedom to choose our own foods. With freedom comes responsibility, and that is a responsibility worth preserving.