Few scientific topics have had as much media coverage as greenhouse gas effects on climate change. The theory is certainly familiar to all of us. Various greenhouse gases (including carbon dioxide, methane, ozone and nitrous oxide) surround our planet and hold in the energy from the suns rays. The effect is familiar to anyone who has sat in a closed car on a sunny day. When the temperature outside is eighty degrees, within thirty minutes it will be 114 degrees inside the car. The glass on the car windows acts just like the greenhouse gases in our atmosphere. The more of these gases are retained in our atmosphere, the hotter the planet will become. The consequences are radical shifts in our climate, leading to dangerous storms, hurricanes, flooding and other drastic environmental changes.
Some climate change deniers claim that “Global Warming” cannot be taking place when winters seem to be getting colder along the east coast of the United States. The shifting of the gulf stream, which allows the arctic winters (polar vortex) to slip down into the northern hemisphere, is a natural phenomenon that has been closely observed for decades. Though it is not directly caused by global warming, it can be influenced by it. For example, one study found that the loss of sea ice may be causing more frequent shifts in the polar vortex. This one closely observed weather phenomenon cannot counteract the growing body of evidence of the impact of global warming on the planet—from ice melting to seas rising, and the escalation of record breaking storms in all seasons. While the controversy continues to rage among politicians, reputable scientists are in nearly complete accord that global warming is occurring at alarming rates.
Various agencies have studied human activities to see what changes we can make in order to reduce our impact on the environment. While figures vary from agency to agency, nearly all agree that the greatest change that one individual can make to help reduce global warming is to change their diet. Several scientists have even concluded that the impact of world-wide shift to a vegan diet would have a greater impact than a shift away from fossil fuels.
According to the Worldwatch Institute, “A widely cited 2006 report by the United Nations Food and Agriculture Organization, Livestock’s Long Shadow, estimates that 18 percent of annual worldwide GHG emissions are attributable to cattle, buffalo, sheep, goats, camels, pigs, and poultry. But recent analysis by Goodland and Anhang finds that livestock and their byproducts actually account for at least 32.6 billion tons of carbon dioxide per year, or 51 percent of annual worldwide GHG emissions. Reviewing both direct and indirect sources of GHG emissions from livestock, the study finds that previous calculations have both underestimated and overlooked certain emissions sources as well as assigned emissions they deem to be livestock-related to the wrong sectors. The authors locate these discrepancies in previous analyses of livestock respiration, land use, and methane. Based on their research, Goodland and Anhang conclude that replacing livestock products with soy-based and other alternatives would be the best strategy for reversing climate change. ‘This approach would have far more rapid effects on GHG emissions and their atmospheric concentrations-and thus on the rate the climate is warming-than actions to replace fossil fuels with renewable energy.’”
Why the wide discrepancy between the estimates of the Food and Agricultural Organization’s 14.5 percent and Goodland and Anhang’s 51 percent impact? For one thing, some estimates don’t take into consideration that carbon dioxide isn’t the only greenhouse gas being produced by the meat and dairy industries. While carbon dioxide is the major concern when discussing most industries, it is actually among the least damaging of the greenhouse gases. Methane has an impact that is much greater.
As Gayathri Vaidyanathan recently wrote in a Scientific American article, “While CO2 persists in the atmosphere for centuries, or even millennia, methane warms the planet on steroids for a decade or two before decaying to CO2. In those short decades, methane warms the planet by 86 times as much as CO2, according to the Intergovernmental Panel on Climate Change.”
While every animal produces methane during digestion, including humans, farm animals are the top producers of methane gas. They not only produce methane in the form of flatulence during digestion, but their feces continue to pollute the environment long after the animal has gone to the slaughterhouse. A study by NASA’s Goddard Institute [“Ruminants or non-ruminants? Methane emissions per animal per year”] shows that a single human produces .12 kg of methane annually. But a single pig produce 1.5 kg of methane annually—that’s thirteen times as much as a human produces. And, a single cow produces 120 kg annually—that’s a thousand times as much methane as a human produces!
The manure from livestock also produces nitrous oxide. Nitrous oxide is 300 times more potent as a greenhouse gas than carbon dioxide. Nitrous oxide is produced as the manure breaks down in the composting process. According the the Food and Agricultural Organization’s estimates livestock contributes 65% of human generated nitrous oxide, through manure and through the chemically fertilized fields of feed crops.
Suzanne Goldenberg has written, “Nitrous oxide, released by fertilizers and animal manure, is the most potent of the greenhouse gases that cause climate change. The UN’s climate body has called for deep cuts to those emissions. Growing feed crops, for cattle and pigs, produces more of those emissions than crops that go directly into the human food chain. Eating less meat would reduce demand for fertilizer as well as reduce the amount of manure produced.”
By eliminating meat and dairy from your diet, you could be cutting carbon dioxide emissions by a conservative 14.5%, methane emissions by 37% and nitrous oxide emissions by 65% (according to the FAO)–all while enjoying delicious plant based meals. Why not make the shift today, and do your part toward reducing global warming?