Methane is a greenhouse gas much like carbon dioxide (CO2). A single cow releases between 70 and 120 kg of methane, on average, per year. The negative climate effects from methane, however, are approximately 23 times more devastating than those from CO2; a cow’s release of 100 kg of methane in one year is equivalent to 2,300 kg of CO2 per year!
To put the 100 kg of methane/2,300 kg of CO2 into perspective, let’s compare the CO2 to burning petrol. That same amount of CO2 produced by one cow in a year is equivalent to the amount of CO2 generated from burning 1,000 liters of petrol. To further put this into perspective, 1,000 liters of petrol could fuel a car for 12,5000 km (~7,767 miles) if that car uses 8 liters of petrol per 100 km.
There are approximately 1.5 billion cows and bulls worldwide. All ruminants, animals that regurgitate their food, emit around 32.6 billion tons of CO2 per year. Additionally, the clearing of tropical forests and rainforest to provide for more grazing and farmlands is responsible for an addition 2.8 billion metric tons of CO2 emissions per year.
In 2006, the United Nations Food and Agricultural Organization (FAO) reported that livestock accounted for 18% of greenhouse gases, making livestock emissions “one of the most significant contributors to today’s most serious environmental problems.”
More recently, however, the Worldwatch Institute, a Washington D.C. environmental think-tank, reported that livestock emissions actually account for an astounding 51%, not 18%, of greenhouse gases; "Livestock are one of the most significant contributors to today's most serious environmental problems. Urgent action is required to remedy the situation." FAO newsroom, Livestock a major threat to environment, 29 November 2006, Rome.
The same report notes that 30% of the earth’s entire land surface is now used by livestock, mostly for permanent pastures, but also for arable land used to provide feed for the livestock. Clearing forests to create more space for livestock is a huge driver of deforestation. In Latin America, for example, around 70% of former Amazon forests are now used strictly for grazing livestock.
Are cows to blame for global warming? Are cattle the true cause for climate change?
Farming’s impact on global warning in undeniable and, since farming serves consumers’ demands for food, we should all rethink our forms of nourishment.
Currently, people are consuming more meat and dairy products than ever before, and the worldwide meat production is projected to more than double by 2050 (up to 465 tons)! At the same time, milk production will skyrocket from 580 to 1,043 million tons.
Producing only one kilogram of beef emits greenhouse gases equivalent to 36.4 kilograms of CO2 as well as fertilizing compounds equivalent to 340 grams of sulphur dioxide and 59 grams of phosphate; additionally, the production of one kilogram of beef uses 169 megajoules of energy. To put this another way, the emissions from only one kilogram of beef is equivalent to the amount of CO2 produced by 250 kilometers driven by the average European car in addition to 20 days worth of light using a 100-watt bulb. New Scientist magazine, 18 July 2007, page 15.
The following table shows how much CO2 is emitted as a result of producing only one kilogram of various types of meats:
|1 kg of meat from||produces kg CO2e|
Conclusion: Eat fewer meat and dairy products
To reduce your personal carbon footprint and to reduce our negative impact on the environment, we all need to eat fewer meat and dairy products. As Albert Einstein, a 1921 Nobel prize recipient, once said: “Nothing will benefit human health and increase chances for survival of life on Earth as much as the evolution to a vegetarian diet.”