Low carbon diet

A low carbon diet refers to making lifestyle choices to reduce the greenhouse gas emissions resulting from energy use. [http://www.time.com/time/health/article/0,8599,1552237,00.html Stacie Stukin, “The Low Carbon Diet,” Time Magazine, Oct. 30, 2006] ] More specifically, a low carbon diet refers to making choices about eating that reduce greenhouse gas emissions (GHGe) as a response to estimates that the U.S. food system is responsible for at least 20 percent of U.S. greenhouse gases.20% of GHGe from food industry] This estimate may be low, as it counts only direct sources of GHGe. Indirect sources such as U.S. demand for products grown overseas are not counted in the 20 percent figure. A low carbon diet minimizes the emissions released from the production, packaging, processing, transport, preparation and waste of food. Major tenets of a low carbon diet include eating less meat and cheese, eating food grown locally and seasonally, eating less processed and packaged foods and reducing waste from food by proper portion size, recycling or composting. [http://www.cnsnews.com/ViewCulture.asp?Page=/Culture/archive/200704/CUL20070418c.html Randy Hall, “Low Carbon Diet' Aims to Take Bite Out of Global Warming,” Cybercast News Service, April 18, 2007] ]

Background on diet and greenhouse gas emissions

The U.S. food system emits four of the greenhouse gases associated with climate change: carbon dioxide, methane, nitrous oxide, and chlorofluorocarbons.STAT saying that those four are emitted] The burning of fossil fuels (such as oil and gasoline) to power vehicles that transport food for long distances by air, ship, truck and rail releases carbon dioxide (CO2), the primary gas responsible for global warming. Methane gas (CH4) is 23 times more powerful at trapping heat than carbon dioxide and is a byproduct of livestock production and landfills.“Sources and Emissions: Methane,” U.S. Environmental Protection Agency, Jun. 2, 2006.] Nitrous oxide (N2O) is 200 times more heat-trapping than carbon dioxide and is emitted as a result of over-tilling and excessive irrigation practices.STAT saying that those four are emitted] Finally, chlorofluorocarbons (CFCs) are emitted from mechanical refrigerating and freezing mechanisms – both staples in food shipment and storage.CFC STAT]

High carbon and low carbon food choices

Certain foods require more fossil fuel inputs than others, making it possible to go on a low carbon diet and reduce one’s carbon footprint by choosing foods that need less fossil fuel and therefore emit less carbon dioxide and other greenhouse gases.

Livestock production

Beef and dairy are particularly high in their levels of greenhouse gas emissions. Feed is a significant contributor to emissions from animals raised in Confined Animal Feeding Operations (CAFOs) or factory farms, as corn or soy beans must be fertilised, irrigated, processed into animal feed, packaged and then transported to the CAFO. In 2005, CAFOs accounted for 74% of the world's poultry production, 50% of pork, 43% of beef, and 68% of eggs, according to the [Worldwatch Institute] . Proportions are significantly higher in developed countries, but are growing rapidly in developing countries, where demand is also growing fast [Danielle Nierenberg, Lisa Mastny, 2005, Worldwatch Paper #171: Happier Meals: Rethinking the Global Meat Industry, p. 11-12] .

By contrast, grass-fed beef is estimated to produce 40% less greenhouse emissions, due to much lower carbon emissions from feed production, and also higher digestibility of grass by cattle, resulting in less methane production [Brian Halweil and Danielle Nierenberg, 2008, Meat and Seafood: The Global Diet’s Most Costly Ingredients, in The Worldwatch Institute's State of the World 2008, p.65] .

Additionally, 37 percent of all anthropogenic methane, comes from livestock production, generated by the digestive system of ruminants such as cows, sheep and goats.H. Steinfeld, et al., “Livestock’s Long Shadow: Environmental Issues and Options,” Livestock, Environment and Development (2006).] Because CAFO production is highly centralised, the transport of animals to slaughter and then to distant retail outlets is a further source of greenhouse gas emissions.

Meat-heavy diets therefore have a major impact on greenhouse gas emissions; it is estimated that livestock production is responsible for 18 percent of worldwide greenhouse gas emissions.H. Steinfeld, et al., “Livestock’s Long Shadow: Environmental Issues and Options,” Livestock, Environment and Development (2006).] The simplest way to reduce carbon dioxide and methane emissions from the diet is to eat less beef, lamb and cheese, seek out locally-produced, grass-fed options, or eliminate them from the diet altogether.

Distance traveled and method of transit

Transport of food across great distances of land or sea in high speed or refrigerated ships or airplanes is a contributor to carbon dioxide emissions in the food industry. Some studies have argued that growing food only accounts for 20 percent of the energy required for many food products; for irrigation, chemical use and mechanization of farm equipment; transportation and processing account for the other 80 percent. [http://www.earth-policy.org/Updates/2005/Update48.htm Danielle Murray, “Oil and Food: A Rising Security Challenge,” Earth Policy Institute, May 9, 2005] ] Other studies have found that carbon emissions from transport account for only 10-15% of the total carbon emissions of food. [http://environment.newscientist.com/channel/earth/mg19926731.700-what-is-your-dinner-doing-to-the-climate.html] Bijal Trevedi, "What Is Your Dinner Doing to the Climate", New Scientist, September 11, 2008] A locavore describes a person attempting to eat a diet consisting of foods harvested from within a 100-mile radius.

Processing, packaging and waste

Highly processed foods such as granola bars come in individual packaging, demanding high energy inputs and resulting in a lot of packaging waste. These products contribute up to a third of total energy inputs for food consumption, as their ingredients are shipped from all over, processed, packaged, trucked to storage, then transported to retail outlets. Bottled water is another example of a highly packaged, wasteful food product. It is estimated that Americans throw away 40 million plastic water bottles every day, and bottled water is often shipped trans-continentally. Carbonated water must be chilled and kept under pressure during storage and transport so as to keep the carbon dioxide dissolved. This factor contributes greater energy usage for products shipped longer distances. Drinking purified tap water is a lower carbon choice.

See also

*Sustainable food system
*Carbon diet
*The 100-Mile Diet

Notes

Additional references

* [http://www.sciencedirect.com/science/article/B6VDY-47RBKSP-4/2/67f10617a98a0490a6fa7f7569f198e5 Annika Carlsson-Kanyama, Marianne Ekstrom, Helena Pipping Shanahan, “Food and life cycle energy inputs: consequences of diet and ways to increase efficiency,” Ecological Economics, 2003]
* [http://www.msnbc.msn.com/id/5279230/ Miguel Llanos, “Plastic bottles pile up as mountains of waste,” (2005), MSNBC]

External links

* [http://lowcarbondiet.ca/ Low Carbon Diet]
* [http://www.empowermentinstitute.net/lcd/ Empowerment Institute Low Carbon Diet]