Seafood, beef, poultry, pork, etc., are all provided for our consumption, often times at the expense of the animals themselves and/or their surrounding environment. While the disturbing facts relating to the horrid treatment of animals in industrialized livestock operations, and their negative effects on human health (heart disease, drug resistant bacteria, endocrine disruption, increased risk of certain cancers, etc.), are enough to make even the most carnivorous of us reconsider our animal intake, a new study finds that livestock (cows, pigs, chickens, sheep, etc.) are the single largest single source of CO2 emissions on the planet.
Released by The Worldwatch Institute, the comprehensive study found that 51% of global CO2 emissions (32,564 million tons per year) are directly attributable to livestock and their byproducts; making the generally accepted United Nations Food and Agriculture Organization’s (FAO) 2006 report Livestock’s Long Shadow of 18% (7,516 million metric tons per year of CO2 equivalents) , though still a high number, look good. It also found that mitigating livestock CO2 emissions is the single most effective, easiest (relative to other GHG reduction measures), and fastest way to reduce atmospheric CO2 concentrations.
Why such a discrepancy between the two reports? According to The Worldwatch Institute, many of the emission sources are obvious but underestimated, some are simply overlooked, and some are emissions sources that are already counted but have been assigned to the wrong sectors. Data on livestock vary from place to place and are affected by unavoidable imprecision; where it was impossible to avoid imprecision in estimating any sum of GHGs. World Watch strove to minimize the sum so its overall estimate could be understood as conservative.
The report itself is fairly comprehensive, but easily understandable as it’s in laymen terms. I encourage readers to look it over before becoming defensive or guilty of your eating habits. Here are a few excerpts (edited in some places for brevity) which I found interesting:
The Big Picture
We begin with the FAO’s 7,516 million tons of CO2e per year attributable to livestock, an amount established by adding up GHG emissions involved in clearing land to graze livestock and grow feed, keeping livestock alive, and processing and transporting the end products.We show that 25,048 million tons of CO2e attributable to livestock have been undercounted or overlooked; of that subtotal, 3,000 million tons are misallocated and 22,048 million tons are entirely uncounted. When uncounted tons are added to the global inventory of atmospheric GHGs, that inventory rises from 41,755 million tons to 63,803 million tons. FAO’s 7,516 million tons of CO2e attributable to livestock then decline from 18 percent of worldwide GHGs to 11.8 percent. Let’s look at each category of uncounted or misallocated GHGs:
Breathing
The FAO excludes livestock respiration from its estimate, per its argument that livestock as as a ‘carbon sink’. This is a flawed way to look at the matter. Sequestration properly refers to extraction of CO2 fromthe atmosphere and its burial in a vault or a stable compound from which it cannot escape over a long period of time. Even if one considers the standing mass
of livestock as a carbon sink, by the FAO’s own estimate the amount of carbon stored in livestock is trivial compared to the amount stored in forest cleared to create space for growing feed and grazing livestock.
More to the point, livestock (like automobiles) are a human invention and convenience, not part of pre-human times, and a molecule of CO2 exhaled by livestock is no more natural than one from an auto tailpipe. Moreover, while over time an equilibriumof CO2may exist between the amount respired by animals and the amount photosynthesized by plants, that equilibriumhas never been static. Today,
tens of billions more livestock are exhaling CO2 than in preindustrial days, while Earth’s photosynthetic capacity (its capacity to keep carbon out of the atmosphere by absorbing it in plant mass) has declined sharply as forest has been cleared. (Meanwhile, of course, we add more carbon to the air by burning fossil fuels, further overwhelming the carbon absorption system.)
Land
As there is now a global shortage of grassland, practically the only way more livestock and feed can be produced is by destroying natural forest. Growth inmarkets for livestock products is greatest in developing countries,where rainforest normally stores at least 200 tons of carbon per hectare. Where forest is replaced bymoderately degraded grassland, the tonnage of carbon stored per hectare is reduced to 8.
On average, each hectare of grazing land supports no more than one head of cattle,whose carbon content is a fraction of a ton. In comparison, over 200 tons of carbon per hectare may be released within a short time after forest and other vegetation are cut, burned, or chewed. From the soil beneath, another 200 tons per hectare may be released, with yet more GHGs from livestock respiration and excretions. Thus, livestock of all types provide minuscule carbon “piggybanks” to replace huge carbon stores in soils and forests. But if the production of livestock or crops is ended, then forest will often regenerate. Themain focus in efforts tomitigate GHGs has been on reducing emissions, while—despite its ability to mitigate GHGs quickly and cheaply—vast amounts of potential carbon absorption by trees has been foregone.
Or suppose that land used for grazing livestock and growing feed were used instead for growing crops to be converted more directly to food for humans and to biofuels.Those fuels could replace one-half of the coal used worldwide, which is responsible for about 3,340million tons of CO2e emissions every year. That tonnage represents 8 percent of GHGs in worldwide GHG inventories that omit the additional GHGs assessed by this article, or 5.6 percent of GHGs worldwide when the GHGs assessed in this article are included. If biomass feedstocks are chosen and processed carefully, then biofuels can yield 80 percent less GHGs per unit of energy than coal. Therefore, the extra emissions resulting from using land for livestock and feed can be estimated to be 2,672 million tons of CO2e, or 4.2 percent of annual GHG emissions worldwide.
Methane
According to the FAO, 37 percent of human induced methane comes from livestock. Although methane warms the atmosphere much more strongly than does CO2, its half-life in the atmosphere is only about 8 years, versus at least 100 years for CO2. As a result, a significant reduction in livestock raised worldwide would reduce GHGs relatively quickly compared withmeasures involving renewable energy and energy efficiency.
Using a Global Warming Potential (GWP) of 72, livestock methane is responsible for 7,416 million tons of CO2e or 11.6 percent of worldwide GHGs. So using the appropriate timeframe of 20 years instead of 100 years for methane raises the total amount of GHGs attributable to livestock products by 5,047 million tons of CO2e or 7.9 percentage points. (Further work is needed to re-calibrate methane emissions other than those attributable to livestock products using a 20-year timeframe.)
Feedlot's waste management lagoon
Other Sources
Four additional categories of GHGs adding up to at least 5,560million tons of CO2e (8.7 percent of GHGs emissions) have been overlooked or undercounted by the FAO and uncounted in the existing inventory of worldwide GHGs:
First, we calculate that the increase in livestock products worldwide from 2002 to
2009 accounts for about 2,560million tons of CO2e, or 4.0 percent of GHG emissions.
Second, the FAO and others have documented frequent undercounting in official statistics of both pastoral and industrial livestock. Livestock’s Long Shadow not only uses no correction factor for such undercounting, but in some sections actually uses lower numbers than appear in FAO statistics and elsewhere. The report also states that 21.7 billion head of livestock were raised worldwide in 2002, while many nongovernmental organizations report that about 50 billion head of livestock were raised each year in the early 2000s. If the true number is closer to 50 billion than to 21.7 billion, then the percentage of GHGs worldwide attributable to undercounting in official livestock statistics would likely be over 10 percent.
Third, the FAO uses citations for various aspects of GHGs attributable to livestock dating back to such years as 1964, 1982, 1993, 1999, and 2001. Emissions today would be much higher.
Fourth, the FAO cites Minnesota as a rich source of data. But if these data are generalized to the world then they understate true values, as operations inMinnesota aremore efficient than operations inmost developing countries where the livestock sector is growing fastest.
Enormous energy-consuming fans on a pig house
Lastly, the FAO leaves uncounted the substantially higher amount of GHGs attributable to each of the following aspects of livestock products versus alternatives to livestock products:
• Fluorocarbons (needed for cooling livestock products much more than alternatives),which have a global warming potential up to several thousand times higher than that of CO2.
• Cooking, which typically entails higher temperatures and longer periods formeat than alternatives, and in developing countries entails large amounts of charcoal (which reduces carbon absorption by consuming trees) and kerosene, each of which emits high levels of GHGs.
• Disposal of inevitably large amounts of liquidwaste from livestock, and waste livestock products in the form of bone, fat, and spoiled products, all of which emit high amounts of GHGswhen disposed in landfills, incinerators, andwaterways.
• Production, distribution, and disposal of byproducts, such as leather, feathers, skin, and fur, and their packaging.
• Production, distribution, and disposal of packaging used for livestock products, which for sanitary reasons is much
more extensive than for alternatives to livestock products.
• Carbon-intensive medical treatment of millions of cases worldwide of zoonotic illnesses (such as swine flu) and
chronic degenerative illnesses (such as coronary heart disease, cancers, diabetes, and hypertension leading to strokes) linked to the consumption of livestock products. Full accounting of GHGs attributable to livestock products would cover portions of the construction and operation of pharmaceutical and medical industries used to treat these illnesses.
Okay Okay…So What Can We Do About It?
It’s pretty simple; less livestock. For many years, advocacy of alternatives to livestock products has been based on arguments about nutrition and health, compassion for animals, and environmental issues other than carbon intensity. These arguments have mostly been ignored and the consumption of livestock products worldwide has
increased, leading some to believe that such advocacy may never succeed. Even urging governments to mandate reductions in livestock production on grounds of climate change may prove ineffective because of the food industry’s own large lobbying capacity.
But if the business case for meat and dairy analogs is clear, then those who normally would lobby governments can appeal directly to leaders in the food industry, who may welcome them as champions. The business risks of analog projects would be similar to those in most other food manufacturing projects, but the risks would be mitigated by the fact that much of the necessary infrastructure (such as for growing and processing grains) already exists. With a rising meat and dairy substitute industry, choices are abound for those looking to decrease their meat and dairy consumption, yet still want the nutritional benefits and taste associated with these foods. And like anything else, it’s also about moderation.
The Good: A study that better accounts for, and quantifies, the actual real-world livestock-attributable GHG-emissions. Shows that addressing livestock production levels can be the most effective and fastest climate change mitigation measure.
The Bad: This study will most likely not change the eating habits of most people, which is the fundamental source of increasing livestock numbers year after year.
The Bottom-Line: Though this study is environmentally compelling in its argument for livestock reduction as an effective climate change measure, the likelihood of getting people to change what goes into their stomachs is slim to none. Real affecting change will have to come from governments and industry.
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