How Do Greenhouse Gases Come From Food Waste?

Food loss and waste contribute significantly to the climate change crisis by generating significant greenhouse gas emissions. The production, transportation, and handling of food generate carbon dioxide (CO2) emissions, which are equivalent to 9.3 billion metric tons of carbon dioxide in 2017. In 2017, food waste was responsible for about half the global food system’s total emissions. Food waste accounts for eight to 10 per cent of global greenhouse gases, with 8-10 of these emissions associated with unconsumed food. Reducing food waste at retail, food service, and household levels can provide multiple benefits.

The Food Waste Index Report 2021 reveals that between food wasted in homes, restaurants, and shops, 17% of food is wasted. When food goes to the landfill and rots, it produces methane, a potent greenhouse gas even more potent than carbon dioxide. About 6-8 of all human-caused greenhouse gas emissions could be reduced if we reduce food waste. Researchers have determined how much this wasted food adds to emissions through phases such as harvest, transportation, and disposal.

Food waste accounts for around one-quarter of greenhouse gas emissions from food, accounting for 6 of total global emissions. Greenhouse gases resulting from rotted and otherwise wasted food account for around half of all global food system emissions. Composting food waste instead can help reduce emissions. As food breaks down in landfills, it generates methane, a potent greenhouse gas that has a global warming potential. Wasted food rotting in landfills also breeds methane as bacteria feed on the organic waste in the oxygen.

How much CO2 does 1 ton of food waste produce?

Last month’s frequently asked questions column discussed the fugitive emissions from food waste that is either composted or landfilled. In summary, at a relatively well-run landfill, each dry ton of food scraps would emit about 0. 75 tons CO 2 equivalent of methane. The green energy from that facility provides about 0. 25 tons of CO 2 as green energy, which results in net emissions of 0. 5 tons of CO 2 per dry ton of food scraps. The net CO 2 emissions from food scraps processed at a well-run composting facility would be 0. 02 tons or a 0. 48 tons CO 2 savings for each ton diverted.

This month’s FAQ calculations provide tools to understand transport emissions in relation to methane avoidance emissions. Transport emissions can be broken down into two parts: 1) smaller trucks that pick stuff up from homes, restaurants, and supermarkets and take them to a centralized location; and 2) loads put into long-haul trucks for the trip to the landfill.

To calculate the carbon footprint of collecting and hauling food waste, the first step is to figure out the quantity of CO2 released when food scraps are transported in long-haul trucks. For example, in Vermont, the total number of people in the state produces about 50 kg of wet food waste per person, which is equivalent to 31, 350 tons of wet food waste per year. To calculate the number of truckloads needed to transport the food waste in Vermont for one year, divide the total quantity of food waste by the amount each truck can carry: 1 truck ÷ 25 tons * 31, 350 tons = 1, 254 truckloads/year.

The next step is figuring out how far each truck has to travel to bring food scraps to the landfill. An approximation is good enough for this exercise; it doesn’t need to get the exact route of each truck. Approximations are also sufficient to calculate this for your own community.

When figuring out the amount of CO2 released taking food waste to the landfill, 401. 3 tons CO 2 is the baseline number. If the total hauling distance to a composting facility is less than to a landfill, not only will you have credits for reduced methane emissions but you will also have credits for reduced transport emissions. For fun, you can figure out how much transport emissions would be reduced if a number of smaller composting facilities were set up across the state.

Assuming we still are looking at full trucks, the transport emissions would be reduced by 75 percent (160 ÷ 40 = 0. 25 or one-quarter of what the distance had been). So the total emissions from hauling to a landfill — 401. 3 tons of CO 2 — would be reduced by one-quarter to 100. 3 tons of CO 2 to transport food scraps to local composting facilities. This is a great reduction — but again, the big bang for the buck comes from taking the food scraps out of the landfill to begin with, i. e., avoiding the methane generation.

Why shouldn’t we waste food?

Reducing food waste can lead to financial benefits and environmental benefits. The Business Case for Reducing Food Loss and Waste suggests that most businesses achieve positive returns from reducing food waste. Financial incentives for farmers, businesses, and organizations can include tax incentives for donating unsold food. Reducing waste volume can make trash pickup less expensive, and some haulers may lower fees if wasted food is separated from trash and sent to a compost facility instead of the landfill. On average, households could save about $370 per person annually.

Resources could be conserved for more productive uses, as wasted food contributes to land, water, labor, energy, and other inputs used in food production, processing, transporting, preparing, storing, and disposing. Reducing greenhouse gases from food rotting in landfills can help mitigate climate change. In 2021, the U. S. Environmental Protection Agency released a report on the environmental impact of food loss and waste, highlighting the environmental benefits of reducing food waste.

How much methane does 1 kg of food waste produce?

Food waste placed in uncapped landfills can lead to severe climate change consequences, as it produces methane emissions when biodegraded. The Volatile Solids (VS) in food waste can be estimated to be 25, with each kg producing 508 ± 21. 5 Litres CH4 and 127m3 of methane from 1 Tonne of food waste. Methane has a global warming potential of 25 times that of carbon dioxide, resulting in 2. 27 Tonnes of equivalent CO2 emissions.

The MyGug Mini version can treat up to 1 tonne of food waste annually, using the methane for cooking or heating, displacing 9 No. Butane gas bottles and resulting in 309kg of CO2 emissions. The MyGug uses approximately 1kW. Hr per day, reducing CO2 emissions by 309kg – 108kg = 201kg/year.

What greenhouse gas is generated by the decomposition of waste?

The United States is the largest source of greenhouse gas (GHG) emissions, with agriculture being the largest contributor. Domestic livestock, such as cattle, swine, sheep, and goats, produce CH4 as part of their digestive process. Animal manure storage and management in lagoons or holding tanks also contribute to CH4 emissions. Land use, land-use change, and forestry (LULUCF) activities also contribute to CH4 emissions.

Natural gas and petroleum systems are the second largest source of CH4 emissions in the US. Methane is emitted during the production, processing, storage, transmission, distribution, and use of natural gas, crude oil, and coal mining. Landfills are the third-largest source of CH4 emissions in the US. Methane is also generated from domestic and industrial wastewater treatment, composting, and anaerobic digestion.

Methane is also emitted from natural sources such as natural wetlands, reservoirs, ponds, termites, oceans, sediments, volcanoes, and wildfires. These sources produce methane through the microbial breakdown of organic matter, with the largest source being unmanaged natural wetlands. For more information on CH4’s role in warming the atmosphere and its sources, visit the Climate Change Indicators page.

How does waste contribute to global warming?

Rising greenhouse gas levels are causing climate change, with solid waste contributing to these emissions through methane generation and nitrous oxide emissions. These gases have high global warming potential, with methane having 21 times the warming potential of carbon dioxide and nitrous oxide having 310 times the warming potential. Connecticut residents generate an estimated 5 pounds of garbage daily, and recycling 1 ton of aluminum is equivalent to not releasing 13 tons of carbon dioxide into the air.

How does fast food contribute to greenhouse gases?

Fast food companies are significantly contributing to global warming despite their pledges to reduce their climate impacts. The supply chain, particularly beef production, is the most significant contributor, as cattle farming generates methane when they belch. A report by The New York Times found that over half of the top 20 food and restaurant companies worldwide have made no progress on their reduction goals or reported rising emissions levels. McDonald’s, for example, pledged in 2021 to be carbon-neutral by 2050, but its emissions have only grown in recent years, reaching a 12% increase in 2021 emissions compared to 2015.

What gas is produced from decomposing waste?

Landfill gas is a mixture of various gases, with methane and carbon dioxide accounting for 90-98 percent. The remaining 2-10 percent includes nitrogen, oxygen, ammonia, sulfides, hydrogen, and other gases. These gases are produced when bacteria break down organic waste, and their production depends on factors such as waste type, landfill age, oxygen content, moisture content, and temperature. The production of these gases typically peaks in five to seven years, but can continue for over 50 years.

Landfill gases can enter buildings through soil, windows, doors, ventilation systems, and cracks in basement floors, walls, utility entry points, sump pump holes, or floor drains. They may also collect in areas with poor ventilation, such as basements, crawlspaces, and utility tunnels.

Odors from landfill gas are primarily caused by hydrogen sulfide and ammonia, which are produced during waste material breakdown. Large amounts of wallboard, for example, can create hydrogen sulfide with a foul smell of rotten eggs, while ammonia has a strong pungent odor. Humans can detect these odors at low levels, generally below levels that would cause health effects.

How much greenhouse gas does food produce?

Around 25-30% of global emissions come from our food systems, with a rise to around one-third when including all agricultural products. People are increasingly aware that their diet has a climate cost, and the food system contributes to around one-third of emissions. A previous study estimated that the food system was responsible for one-quarter of global emissions, but a new study by Monica Crippa and colleagues in Nature Food estimates a higher share of one-third of emissions. The exact number depends on factors such as deforestation, land use, transport, and packaging.

What greenhouse gas is created by wastewater?

Greenhouse gas (GHG) emissions from wastewater treatments are derived primarily from direct production, such as nitrous oxide (N₂O) and methane (CH₄), and indirect emissions from energy and chemical consumption. ScienceDirect employs the use of cookies, and all rights are reserved for text and data mining, AI training, and similar technologies. The open access content is licensed under Creative Commons terms.

How does food impact GHG?

Food is a vital component of life and a significant contributor to greenhouse gas emissions. The agriculture sector contributes to nearly half of methane (CH4) emissions, two-thirds of nitrous oxide (N2O) emissions, and three of carbon dioxide (CO2) emissions from human activities worldwide. These emissions account for 80 percent of today’s gross warming, suggesting that agriculture may be responsible for approximately 15 of current warming levels. However, only one-third of countries reference agriculture mitigation measures in nationally determined contributions to the Paris Agreement.

Estimating the warming impact of the agriculture sector is challenging due to its emission of multiple greenhouse gases with varying radiative properties, atmospheric longevities, and emission sources. Carbon dioxide, a gas that can last hundreds of years in the atmosphere, is emitted throughout the food supply chain from energy use from cultivation machinery and product transportation. Methane, a gas capable of trapping over 100 times more heat than CO2, is primarily emitted from animal products and rice production through enteric fermentation, manure management, and rice paddy methanogenesis. Nitrous oxide, which can trap over 250 times more heat than CO2, is emitted through synthetic fertilizer use, nitrogen-fixing crop cultivation, and ruminant excretion on rangelands.

To assess the warming impacts of agriculture, studies often use the metrics global warming potential (GWP) and CO2 equivalence (CO2 e) to estimate the impact of these gases on a common scale. However, these metrics do not accurately convey climate impacts because they do not account for continuous and evolving emissions, calculate warming impacts over time, and require an arbitrary time horizon that skews the climate impacts of short- or long-lived greenhouse gases.

How to calculate greenhouse gas emissions from food waste?

The country-level emission estimates can be calculated using the following formula: Emissions = A * EF, where Emissions represents GHG emissions in Gg CH4 yr-1, A represents activity data in Gg yr-1, and EF represents the default IPCC emission factor in Gg CH4/C deposited ratio.