Low carbon diet
Encyclopedia
A low carbon diet refers to making lifestyle choices to reduce the greenhouse gas
emissions (GHGe) resulting from energy use. It is estimated that the U.S. food system is responsible for at least 20 percent of U.S. greenhouse gases. This estimate may be low, as it counts only direct sources of GHGe. Indirect sources, such as demand for products from other countries, are often not counted. 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 industrial meat
and dairy
, eating less industrially produced food in general, eating food grown locally and seasonally, eating less processed and packaged foods and reducing waste from food by proper portion size, recycling
or composting.
, methane
, nitrous oxide
, and chlorofluorocarbons. 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. 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. Finally, chlorofluorocarbons (CFCs) are emitted from mechanical refrigerating and freezing mechanisms – both staples in food shipment and storage.
by choosing foods that need less fossil fuel and therefore emit less carbon dioxide and other greenhouse gases. Vegans contend that the best choice for reducing individual greenhouse gas emissions is an organic vegan diet. An organic vegan diet may reduce greenhouse gas emissions by 1.5 tons per year (compared to the standard American diet). Choosing exclusively plant based (vegan) foods for one meal out of every five (20%) may cut greenhouse gas emissions by the same amount as switching from a standard to a hybrid-powered car, though this would depend on what the plant foods are, how they are grown, how they are packaged, how (and how far) they are transported, how they are stored, and so on. Cundiff and Harris write: "The American Dietetic Association (ADA) and Dietitians of Canada position paper on vegetarian diets officially recognizes that well-planned vegan diets are appropriate for infancy and childhood. The American Academy of Pediatrics concurs. "
and dairy
cattle can be 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.
By contrast, grass-fed cattle are estimated to account for 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. This number, however, does not take into account their crucial role in establishing a healthy pastoral ecosystem, which can function as a highly efficient system for carbon sequestration. Rotational grazing of ruminant
s (cattle, sheep, goats, etc.) and birds (chickens, turkeys, etc.) on untilled pasture land promotes rapid topsoil accumulation, representing a major carbon sink. Polyface Farm
in Virginia, U.S.A., a pioneering farm in rotational grazing or "grass farming", has built up its topsoil at a rate of about one inch per year, which is well over one hundred times the rate of a healthy forest, increasing soil organic matter levels by an average of .14% per year or 2.7 tons of carbon per acre per year. Polyface's claims have not been independently academically peer reviewed, and the soil's carbon sequestration would have to be weighed against the positive methane and nitrous oxide emissions from the animals. There is increasing criticism of Polyface because they buy in non-organic feed for their poultry and pigs who do not eat pasture and so carbon accumulation means a net loss elsewhere. Additionally, Polyface purchases their hens from a CAFO hatchery where male chicks are destroyed.
Additionally, 37 percent of all anthropogenic methane comes from industrial livestock production, generated by the digestive system of ruminants such as cows, sheep and goats. 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.
Diets heavy in meat and dairy have a major impact on greenhouse gas emissions; it is estimated that livestock production is responsible for 18 percent of worldwide greenhouse gas emissions. This is the second-largest source of greenhouse gas emissions, and more than all forms of transportation combined. One simple way to reduce carbon dioxide and methane emissions from the diet is to eat less beef, lamb and dairy
.
When looking at total greenhouse gases (not just carbon dioxide), 83% of emissions come from the actual production of the food because of the methane released by livestock and the nitrous oxide due to fertilizer.
The word locavore describes a person attempting to eat a diet consisting of foods harvested from within a 100-mile radius.
Some studies have criticized the emphasis on local food, claiming that it romanticizes local production, but does not produce very much environmental benefit. Transportation accounts for a relatively small portion of overall energy consumption in food production, and locally produced food may be much more energy intensive than food produced in a better area. Additionally the emphasis on "inefficient" local producers over more efficient ones further away may be damaging.
. 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.
Greenhouse gas
A greenhouse gas is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in the Earth's atmosphere are water vapor, carbon dioxide, methane, nitrous oxide, and ozone...
emissions (GHGe) resulting from energy use. It is estimated that the U.S. food system is responsible for at least 20 percent of U.S. greenhouse gases. This estimate may be low, as it counts only direct sources of GHGe. Indirect sources, such as demand for products from other countries, are often not counted. A low carbon diet minimizes the emissions released from the production, packaging, processing
Food processing
Food processing is the set of methods and techniques used to transform raw ingredients into food or to transform food into other forms for consumption by humans or animals either in the home or by the food processing industry...
, transport, preparation and waste of food. Major tenets of a low carbon diet include eating less industrial meat
Meat
Meat is animal flesh that is used as food. Most often, this means the skeletal muscle and associated fat and other tissues, but it may also describe other edible tissues such as organs and offal...
and dairy
Dairy
A dairy is a business enterprise established for the harvesting of animal milk—mostly from cows or goats, but also from buffalo, sheep, horses or camels —for human consumption. A dairy is typically located on a dedicated dairy farm or section of a multi-purpose farm that is concerned...
, eating less industrially produced food in general, eating food grown locally and seasonally, eating less processed and packaged foods and reducing waste from food by proper portion size, recycling
Recycling
Recycling is processing used materials into new products to prevent waste of potentially useful materials, reduce the consumption of fresh raw materials, reduce energy usage, reduce air pollution and water pollution by reducing the need for "conventional" waste disposal, and lower greenhouse...
or composting.
Background on diet and greenhouse gas emissions
In the U.S., the food system emits four of the greenhouse gases associated with climate change: carbon dioxideCarbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
, methane
Methane
Methane is a chemical compound with the chemical formula . It is the simplest alkane, the principal component of natural gas, and probably the most abundant organic compound on earth. The relative abundance of methane makes it an attractive fuel...
, nitrous oxide
Nitrous oxide
Nitrous oxide, commonly known as laughing gas or sweet air, is a chemical compound with the formula . It is an oxide of nitrogen. At room temperature, it is a colorless non-flammable gas, with a slightly sweet odor and taste. It is used in surgery and dentistry for its anesthetic and analgesic...
, and chlorofluorocarbons. 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
Livestock
Livestock refers to one or more domesticated animals raised in an agricultural setting to produce commodities such as food, fiber and labor. The term "livestock" as used in this article does not include poultry or farmed fish; however the inclusion of these, especially poultry, within the meaning...
production and landfills. Nitrous oxide (N2O) is 200 times more heat-trapping than carbon dioxide and is emitted as a result of over-tilling and excessive irrigation
Irrigation
Irrigation may be defined as the science of artificial application of water to the land or soil. It is used to assist in the growing of agricultural crops, maintenance of landscapes, and revegetation of disturbed soils in dry areas and during periods of inadequate rainfall...
practices. Finally, chlorofluorocarbons (CFCs) are emitted from mechanical refrigerating and freezing mechanisms – both staples in food shipment and storage.
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 footprintCarbon footprint
A carbon footprint has historically been defined as "the total set of greenhouse gas emissions caused by an organization, event, product or person.". However, calculating a carbon footprint which conforms to this definition is often impracticable due to the large amount of data required, which is...
by choosing foods that need less fossil fuel and therefore emit less carbon dioxide and other greenhouse gases. Vegans contend that the best choice for reducing individual greenhouse gas emissions is an organic vegan diet. An organic vegan diet may reduce greenhouse gas emissions by 1.5 tons per year (compared to the standard American diet). Choosing exclusively plant based (vegan) foods for one meal out of every five (20%) may cut greenhouse gas emissions by the same amount as switching from a standard to a hybrid-powered car, though this would depend on what the plant foods are, how they are grown, how they are packaged, how (and how far) they are transported, how they are stored, and so on. Cundiff and Harris write: "The American Dietetic Association (ADA) and Dietitians of Canada position paper on vegetarian diets officially recognizes that well-planned vegan diets are appropriate for infancy and childhood. The American Academy of Pediatrics concurs. "
Industrial v. pastured livestock
BeefBeef
Beef is the culinary name for meat from bovines, especially domestic cattle. Beef can be harvested from cows, bulls, heifers or steers. It is one of the principal meats used in the cuisine of the Middle East , Australia, Argentina, Brazil, Europe and the United States, and is also important in...
and dairy
Dairy product
Dairy products are generally defined as foods produced from cow's or domestic buffalo's milk. They are usually high-energy-yielding food products. A production plant for such processing is called a dairy or a dairy factory. Raw milk for processing comes mainly from cows, and, to a lesser extent,...
cattle can be 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
Maize
Maize known in many English-speaking countries as corn or mielie/mealie, is a grain domesticated by indigenous peoples in Mesoamerica in prehistoric times. The leafy stalk produces ears which contain seeds called kernels. Though technically a grain, maize kernels are used in cooking as a vegetable...
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.
By contrast, grass-fed cattle are estimated to account for 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. This number, however, does not take into account their crucial role in establishing a healthy pastoral ecosystem, which can function as a highly efficient system for carbon sequestration. Rotational grazing of ruminant
Ruminant
A ruminant is a mammal of the order Artiodactyla that digests plant-based food by initially softening it within the animal's first compartment of the stomach, principally through bacterial actions, then regurgitating the semi-digested mass, now known as cud, and chewing it again...
s (cattle, sheep, goats, etc.) and birds (chickens, turkeys, etc.) on untilled pasture land promotes rapid topsoil accumulation, representing a major carbon sink. Polyface Farm
Polyface Farm
Polyface Farm is a farm located in rural Swoope, Virginia, United States, run by Joel Salatin and his family. The farm is driven using unconventional methods with the goal of "emotionally, economically and environmentally enhancing agriculture". This farm is where Salatin developed and put into...
in Virginia, U.S.A., a pioneering farm in rotational grazing or "grass farming", has built up its topsoil at a rate of about one inch per year, which is well over one hundred times the rate of a healthy forest, increasing soil organic matter levels by an average of .14% per year or 2.7 tons of carbon per acre per year. Polyface's claims have not been independently academically peer reviewed, and the soil's carbon sequestration would have to be weighed against the positive methane and nitrous oxide emissions from the animals. There is increasing criticism of Polyface because they buy in non-organic feed for their poultry and pigs who do not eat pasture and so carbon accumulation means a net loss elsewhere. Additionally, Polyface purchases their hens from a CAFO hatchery where male chicks are destroyed.
Additionally, 37 percent of all anthropogenic methane comes from industrial livestock production, generated by the digestive system of ruminants such as cows, sheep and goats. 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.
Diets heavy in meat and dairy have a major impact on greenhouse gas emissions; it is estimated that livestock production is responsible for 18 percent of worldwide greenhouse gas emissions. This is the second-largest source of greenhouse gas emissions, and more than all forms of transportation combined. One simple way to reduce carbon dioxide and methane emissions from the diet is to eat less beef, lamb and dairy
Dairy
A dairy is a business enterprise established for the harvesting of animal milk—mostly from cows or goats, but also from buffalo, sheep, horses or camels —for human consumption. A dairy is typically located on a dedicated dairy farm or section of a multi-purpose farm that is concerned...
.
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 21% of the energy required for many food products. Transportation (14%), processing (16%), packaging (7%), food retailing (4%), restaurants and caterers (7%) and home refrigeration and preparation (32%) account for the rest. Another study, by a researcher at Carnergie Mellon University, found that carbon emissions from transport account for 11% of the total carbon emissions of food, of which the transportation from producer to consumer accounts for 4%.When looking at total greenhouse gases (not just carbon dioxide), 83% of emissions come from the actual production of the food because of the methane released by livestock and the nitrous oxide due to fertilizer.
The word locavore describes a person attempting to eat a diet consisting of foods harvested from within a 100-mile radius.
Some studies have criticized the emphasis on local food, claiming that it romanticizes local production, but does not produce very much environmental benefit. Transportation accounts for a relatively small portion of overall energy consumption in food production, and locally produced food may be much more energy intensive than food produced in a better area. Additionally the emphasis on "inefficient" local producers over more efficient ones further away may be damaging.
Processing, packaging and waste
Highly processed foods such as granola bars come in individual packaging, demanding high energy inputs and resulting in packaging wasteWaste
Waste is unwanted or useless materials. In biology, waste is any of the many unwanted substances or toxins that are expelled from living organisms, metabolic waste; such as urea, sweat or feces. Litter is waste which has been disposed of improperly...
. 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
Bottled water
Bottled water is drinking water packaged in plastic or glass water bottles. Bottled water may be carbonated or not...
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
Carbonated water
Carbonated water is water into which carbon dioxide gas under pressure has been dissolved, a process that causes the water to become effervescent....
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
Tap water
Tap water is a principal component of "indoor plumbing", which became available in urban areas of the developed world during the last quarter of the 19th century, and common during the mid-20th century...
is a lower carbon choice.
See also
- Sustainable food system
- Carbon dietCarbon DietA carbon diet refers to reducing the impact on climate change by reducing greenhouse gas production.Individuals and businesses produce carbon dioxide from daily activities such as driving, heating, and the consumption of products and services...
- Farm to fork
- The 100-Mile Diet
- Vertical farmingVertical farmingVertical farming is a concept that argues that it is economically and environmentally viable to cultivate plant or animal life within skyscrapers, or on vertically inclined surfaces...
Additional references
- 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
- Miguel Llanos, “Plastic bottles pile up as mountains of waste,” (2005), MSNBC