Are cows the cause of global warming?

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
 beef 34.6
 lamb 17.4
 pork 6.35
 chicken 4.57

Source: Environmental Impacts on Food Production and Consumption.


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



CO2 emission of food

Thank you for the hint. I've corrected it.

CO2 emission of food / meat as cause for global warming

Your reasoning about vegetables is wrong. It requires much less land to produce enough vegetables to feed a person. Producing meat to feed a person requires much much more land! The table below shows the amount of food required to gain 1 kg additional weight for main species:

Food conversion for main species

On the land required to produce 1 kg of meat, about 200 kg of potatoes could be produced! If all Americans would consume only 10% less meat, the amount of economized corn could feed 1 billion people!

The cattles you mentioned have indeed been around a long time ago. But they were grass fed, sustainably raised in a natural and environmental friendly way. Today's cattle breeding however is factory farming (feedlots) causing a lot of additional problems (e.g. nitrous oxides from fertilizers, etc).

There is nothing wrong with naturally grown, grass-fed cattles. But these are very rare species! At least 95% of all meat is produced in feedlots (factory farming).

But let me repeat again: Much less meat can be produced per square meter land with grass-fed grazing cattles compared to feedlots. So the rich western world need to dramatically cut their meat consumption to make the change back from feedlots into grazing, environmental-friendly and outdoor-living cattles realistic.


CO2 emission from raising farm animals for the food industry

Update on January 2018:
Worldwide, livestock accounts for 14.5 percent to 18 percent of human-induced greenhouse gas emissions. (Sourc: New York Times, January 25, 2018)

In other words: the arcticle above about the contribution of cows (or feed breading in general) to global warming is still up-to-date!

Grazing cattles as solution to global warming?

Interesting link. However it is important to see the difference between naturally grown, grazing cattles and the current cattle breeding factories. There is simply not enough land available to breed the current number of cattles in an environmentally friendly way.

Therefore it is inevitable to reduce the average meat consumption in the rich part of the world.

global warming? how much we care?

Global warming is a very sensitive issue that we must not ignore. We can’t blame cows or those farms for this phenomenon. All human is responsible for these. Everyday, each person contributes largely to the global warming unconsciously. Riding a car, or throwing a piece of plastic or paper. Many companies are promoting eco-friendly products like natural spices, biodegradable plastics, electric cars like
peapod car
and the likes. But what really is the real probability that these acts can really contribute to prevent global warming. Further studies is needed to understand carefully the real aspects in this phenomenon.

Are Cows the Cause of Global Warming

One has to agree that sustainable regenerative grazing will probably result in less meat consumption. But, grazing in a sustainable manner like the huge migrating herds of bison, aurochs and antelope that created the deep carbon rich soils of the world's grasslands/breadbaskets such as the north american prairies and plains can sequester vast quantities of carbon up to 3,000 tons of carbon per acre.

When managed intensively, the "standard grazing unit", a 1000 pound cow can capture and store the equivalent of 3 tons of CO2 per year, three times as much as the equivalent methane she produces.

One must remember that the biological decomposition of plants produces methane, whether that decomposition takes place in a herbivore's gut, in the soil in in water (remember swamp gas is methane). I have not seen anything showing that cattle increase the total methane emitted by the same quantity of plants in the soil or in a compost pile. An additional factor promoting grazing is the nature of grasslands. Grasslands and hoofed herbivores including ruminants evolved together. As a result grasslands have to be cut/trimmed to stay healthy. In humid areas such as Illinois or Iowa, the land turns into scrubland, which sequesters little carbon. In semi-arid areas such found west of 98th meridian such as New Mexico, the land turns into desert, highly erodible and subject to oxidation of the any organic material in the soil. Ruminants are nature's chosen trimmers. Their sharp cloven hooves are highly effective in trampling vegetation creating an armor protecting the soil from desiccation, wind and water erosion and promoting water infiltration.

Finally, the only way that much of our land especially in the west is only suitable for grazing. That acreage will only increase as aquifers are depleted by excessive pumping.