Vegetarianism has long sparked heated debates around the dinner table, often centring around issues regarding health and ethics. However in recent times a new debate has been sparked about whether becoming a vegetarian can help abate climate change.
Over the last 30 years, meat consumption has increased greatly, with humans now consuming around 230 million tonnes of meat every year. This increase, which is set to continue with the ever increasing world population, has raised serious questions concerning the sustainability of continuing to eat meat. Can vegetarianism help save the planet, or does it bring problems of its own to the table?
Climate Change and Cows
The main environmental concern regarding the consumption of vast quantities of meat is that all the animals bred for the food market emit methane and other greenhouse gases, which can contribute to global warming. Methane is one of the most effective greenhouse gases, and is 23 times more effective at trapping sunlight than carbon dioxide. The class of animals called ‘ruminants’, which includes cows, sheep and goats, produce the most methane because they have four stomachs for digestion, which contain methane-producing bacteria.
The precise amount of methane released by animals, and hence its contribution to climate change, is a matter of scientific debate and several different measurement techniques are currently implemented. Argentine scientists have trapped cow farts into giant plastic tanks attached to the animals backs. Through this work they have estimated that a cow produces enough methane every day to make them accountable for almost a third of all greenhouse gas emissions from Argentina. Another method for measuring methane produced from cows involves looking at achaeol molecules in dung.
Even at a conservative estimate, the amount of greenhouse gases produced by cows and other rudiments is large. The EPA estimates that a fully grown cow can produce 80-110 kgs of methane a year. As there are around 1.2 billion ruminants across the planet, this means that livestock farming is responsible for 28% of human-related methane emissions.
Furthermore, aside from the gas that is produced directly from the animal, there are many other sources of pollution directly related to cattle:
- Gas from manure
- the petrol used to drive animals to market
- the energy used to export meat across the globe to supermarkets
- the energy required to feed and water the animals
- the energy required to store meat
Taking into account these factors and more, the UN estimated that the total emissions related to animals bred for meat was 18% of the global total. This is higher than all forms of transport put together. Some scientists have even put this figure as high as 51%.
Cows –unwitting enemies of environment. Image credit: NASA
There are many other major environmental issues that are associated with the production of a large amount of meat, including:
Deforestation: Huge swaths of forests across the globe are being destroyed to make way for cattle grazing land. At an estimate, the Smithsonian Institution has said that around 7 football field’s worth of forest is destroyed every minute for farmland. This of course leads to wholesale destruction of ecosystems and the trees that are destroyed are needed to remove carbon dioxide from the atmosphere.
Water Pollution: the tonnes of manure produced every day from the farming of animals often ends up in water systems, and according to the EPA, this is the number one cause of pollution in waterways. Farm run-off can also greatly affect the sea, and has contributed significantly to the ‘dead zone’ in the Gulf of Mexico, an area of ocean the size of the state of Maryland devoid of life.
Keep the Meat?
But is becoming a vegetarian the way to solve this issue? A recent study by Canfield University in the UK found that meat substitutes, such as tofu, lentils and soy, can be just as harmful to the environment because they are often imported, requiring a lot of extra energy. Furthermore, meat substitutes often require large amounts of processing, and require a lot of farmland to produce.
It is thought that the amount of methane produced by farm animals can be greatly reduced by simply changing their diet. For example, a team of Welsh scientists appear to have cut the amount of methane produced by cows by adding garlic to their diet. Other teams from the Argentine National Council of Scientific and Technical Investigations have suggested that emissions can be reduced by a quarter if cows are fed cloves and alfalfa in their meals.
Sources and Further Reading
- Vegetarianism and the Environment, PETA
- Becoming vegetarian 'can harm the environment', The Telegraph, 12/02/2010
- 10 ways vegetarianism can help save the planet, The Guardian, 18/07/2010
- Cow farts collected in plastic tank for global warming study, The Telegraph, 09/07/2009
- Ruminant Livestock, EPA
- Cow methane proof 'is in the pat', BBC News, 08/06/2011