A cow does on overage release between 70 and 120 kg of Methane per year. Methane is a greenhouse gas like carbon dioxide (CO2). But the negative effect on the climate of Methane is 23 times higher than the effect of CO2. Therefore the release of about 100 kg Methane per year for each cow is equivalent to about 2’300 kg CO2 per year.
Let’s compare this value of 2’300 kg CO2: The same amount of carbon dioxide (CO2) is generated by burning 1’000 liters of petrol. With a car using 8 liters of petrol per 100 km, you could drive 12’500 km per year (7’800 miles per year).
World-wide, there are about 1.5 billion cows and bulls. All ruminants (animals which regurgitates food and re-chews it) on the world emit about two billion metric tons of CO2-equivalents per year. In addition, clearing of tropical forests and rain forests to get more grazing land and farm land is responsible for an extra 2.8 billion metric tons of CO2 emission per year!
According to the Food and Agriculture Organization of the United Nations (FAO) agriculture is responsible for 18% of the total release of greenhouse gases world-wide (this is more than the whole transportation sector). Cattle-breeding is taking a major factor for these greenhouse gas emissions according to FAO. Says Henning Steinfeld, Chief of FAO’s Livestock Information and Policy Branch and senior author of the report: "Livestock are one of the most significant contributors to today’s most serious environmental problems. Urgent action is required to remedy the situation."
Livestock now use 30 percent of the earth’s entire land surface, mostly permanent pasture but also including 33 percent of the global arable land used to producing feed for livestock, the report notes. As forests are cleared to create new pastures, it is a major driver of deforestation, especially in Latin America where, for example, some 70 percent of former forests in the Amazon have been turned over to grazing.
Are cows to blame for global warming? Are cattle the true cause for climate change?
We cannot deny that farming has a major impact on global warming. Since farming is basically serving the consumer’s demand for food, we should look at our nourishment. With increased prosperity, people are consuming more meat and dairy products every year. Global meat production is projected to more than double from 229 million tonnes in 1999/2001 to 465 million tonnes in 2050, while milk output is set to climb from 580 to 1043 million tonnes.
A Japanese study showed that producing a kilogram of beef leads to the emission of greenhouse gases with a global warming potential equivalent to 36.4 kilograms of carbon dioxide (CO2). It also releases fertilising compounds equivalent to 340 grams of sulphur dioxide and 59 grams of phosphate, and consumes 169 megajoules of energy (Animal Science Journal, DOI: 10.1111/j.1740-0929.2007.00457.x). In other words, a kilogram of beef is responsible for the equivalent of the amount of CO2 emitted by the average European car every 250 kilometres, and burns enough energy to light a 100-watt bulb for nearly 20 days (New Scientist magazine, 18 July 2007, page 15 ).
The following tables indicates the CO2 production in kg CO2 equivalents per kg of meat depending on the animal:
|1 kg of meat from ||produces kg CO2e |
Source: Environmental Impacts on Food Production and Consumption. http://www.defra.gov.uk/science/project_data/DocumentLibrary/EV02007/EV02007_4601_FRP.pdf
Conclusion: Eat less meat and dairy products
The most important conclusion for ourselves is: Eat much less meat and dairy products. This is one of the most effective ways to reduce our personal carbon footprint and to generally reduce our personal negative impact on the environment.
Finally a quote from Albert Einstein (Nobel prize 1921): Nothing will benefit human health and increase chances for survival of life on Earth as much as the evolution to a vegetarian diet.
Report from FAO: LIVESTOCK’S LONG SHADOW, environmental issues and options