According to a recent comprehensive study by the United Nations Food and Agriculture Organization, agriculture currently contributes 18% of total world greenhouse gas emissions and livestock production accounts for nearly 80% of this (Livestock’s Long Shadow: Environmental Issues and Options, Rome: 2006, p. 112). According to the Intergovernmental Panel on Climate Change 4th Assessment Report, greenhouse gas emissions in 2004 were 49 billion tons CO2 equivalent. 18% of 49 billion tons CO2 equivalent equals 8.82 billion tons CO2 equivalent. Since each 1 ton of carbon equals 3.67 tons of CO2, 8.82 billion tons CO2 equivalent equals 2.38 billion tons carbon equivalent.
Thus meat-eating contributes approximately 2.38 billion tons carbon equivalent to current greenhouse gas emissions (substituting more recent figures for world carbon emissions would push this number up, perhaps over 2 and ½ billion tons). The U.N. Food and Agricultural Organization projects a worldwide doubling in animal production between 2000 and 2050, from 60 billion to 120 billion animals raised annually, which under “business as usual,” will double the greenhouse gas emissions from this sector to 4.76 billion tons. If instead we hold worldwide animal food production steady over the next fifty years, this would provide nearly two and a half carbon wedges (averting a 2.38 billion tons increase). Merely preventing half the projected doubling during that time would supply more than one full carbon wedge (1.19 billion tons averted) (see Gidon Eshel and Pamela Martin, “Diet, Energy, and Global Warming,” Earth Interactions, 10 (2006), paper number nine).
Such veggie wedges might be accomplished non-coercively by increasing the price of meat, removing subsidies for cattle production, banning confined animal feedlot operations (CAFO’s) as the European Union is in process of doing, and directly taxing meat to discourage consumption. These measures could accommodate a reasonable increase in meat-eating in poor countries where many people eat little meat, while providing environmental and health benefits in wealthy countries where people eat more meat than is good for them (Philip Cafaro, Richard Primack and Robert Zimdahl, “The Fat of the Land: Linking American Food Overconsumption, Obesity, and Biodiversity Loss,” Journal of Agricultural and Environmental Ethics, 19 (2006), 541–561). They could complement efforts to improve the conditions under which food animals are raised, changes that may be expensive, but which are arguably demanded by morality anyway.
Several caveats are in order. In some parts of the world, increased meat-eating may represent a real nutritional improvement in people’s diets (parts of Asia). In some areas, meat-eating has not increased at all in recent decades and future increases might may represent a real nutritional improvement in people’s diets (sub-Saharan Africa). In other areas, however, such as the United States, meat-eating should be cut back for human health reasons.
For these reasons, worldwide efforts should emphasize getting over-consumers of meat and animal products to cut back. They should also teach people in countries that are becoming more wealthy the nutritional and health value of their traditional diets. For a detailed discussion of the meat/heat connection, see Global Warning: Climate Change and Farm Animal Welfare from Compassion in World Farming.
Former IPCC Chairman Rajendra Pachauri is a proponent of eating less meat to fight climate change. On September 19, 2008, Pachauri, a vegetarian himself, posted the following message to his blog at rkpachauri.org:
Lifestyle Changes for A Healthy Planet
During the past few weeks I have spoken in public on the benefits of lower consumption of meat as a means to reduce the emissions of greenhouse gases (GHGs). As would be expected I have, as a result, received some comments that are positive and others which amount to strong criticism. My purpose in raising this issue was only to create a debate on the subject. The Synthesis Report which is part of the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) clearly stated, "There is also high agreement and medium evidence that changes in lifestyle and behaviour patterns can contribute to climate change mitigation across all sectors. Management practices can also have a positive role." In my view an important component of lifestyle changes relates to changes in diet which in actual fact may bring about an improvement in human health. In the case of meat consumption there are benefits not only to the individual who reduces consumption of meat but clear advantages in terms of reducing GHG emissions.
The Food and Agriculture Organization (FAO) brought out a report in 2006 which estimates emissions of GHGs from agriculture as a whole, of which 80 percent are accounted for by livestock production. These constitute 18 percent of all GHG emissions from human activities. An interesting comparison between a vegetarian meal and a beef steak, for instance, was provided by The New York Times in its issue of 27 January 2008 which is revealing. A meal consisting of 1 cup of broccoli, 1 cup of eggplant, 4 ounces cauliflower and 8 ounces of rice results in 0.4 pounds of emissions of CO2 equivalent. On the other hand a 6 ounce beef steak results in 10 pounds of CO2 equivalent emissions, which amount to 25 times that of the vegetarian meal with which the comparison was made.
Quite unexpectedly, I received considerable media coverage on my presentation and several comments. The ‘Observer' of the UK on September 7, 2008 carried a front page headline "UN says eat less meat to curb global warming". The UN was in no way involved with the views that I expressed, because they represent my personal views on the subject, of course within the context of lifestyle changes that the IPCC has put forward as a possible approach to mitigation of GHG emissions. Even more unexpected, and somewhat amusing, was the op-ed page article authored by Boris Johnson, the recently elected Mayor of London, which was carried in the Daily Telegraph of September 9. Prior to his election there were references to Mr. Johnson as a joker. He certainly has a sense of humour which I appreciate, particularly since he stated in his article, "No, Rajendra Pachauri, distinguished chairman of the panel, I am not going to have one meat-free day per week. No, I am not going to become a gradual vegetarian. In fact, the whole proposition is so irritating that I am almost minded to eat more meat in response."
All in all I am happy that I have been able to at least stir up a "healthy" debate linking dietary choices with the health of individuals and, of course, the health of the planet, the only one on which we humans can live at present. As a result, I have also received several invitations for speaking on the same subject in other parts of the world, and I might accept some of these to see that there is global attention provided to the excessive consumption of meat and the benefits of reducing it both in terms of human health and the health of the planet. I certainly do not expect people to alter their daily preferences, but perhaps some reflection could bring about changes that may actually result in reducing emissions of GHGs. If that were to happen I would feel satisfied that at least raising this issue was not so futile despite the Hon'ble Mayor of London threatening to eat more meat in response to my provocation. Since I believe he travels on a bicycle, he would probably have to travel a little more to burn up the extra calories! He may then even qualify for an appropriate event in the 2012 Olympics, which are to be staged in London.