What Is The Most Important Source Of Environmental Change?

On this page:

• Overview
• Electricity
• Transportation
• Manufacture
• Commercial/Residential
• Agronomics
• Land Use/Forestry

Overview

Total Emissions in 2019 = half-dozen,558 Million Metric Tons of CO2 equivalent. Percentages may not add together up to 100% due to contained rounding.

* Land Apply, Land-Use Change, and Forestry in the Us is a net sink and removes approximately 12 percent of these greenhouse gas emissions, this net sink is not shown in the higher up diagram. All emission estimates from the Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990–2019.

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Greenhouse gases trap heat and make the planet warmer. Human activities are responsible for almost all of the increment in greenhouse gases in the atmosphere over the last 150 years.^ane The largest source of greenhouse gas emissions from human activities in the U.s. is from called-for fossil fuels for electricity, heat, and transportation.

EPA tracks total U.Southward. emissions by publishing the Inventory of U.S. Greenhouse Gas Emissions and Sinks. This almanac written report estimates the full national greenhouse gas emissions and removals associated with human activities across the United states.

The master sources of greenhouse gas emissions in the United States are:

• Transportation (29 percent of 2019 greenhouse gas emissions) – The transportation sector generates the largest share of greenhouse gas emissions. Greenhouse gas emissions from transportation primarily come up from burning fossil fuel for our cars, trucks, ships, trains, and planes. Over 90 percentage of the fuel used for transportation is petroleum based, which includes primarily gasoline and diesel.ii
• Electricity product (25 percentage of 2019 greenhouse gas emissions) – Electricity production generates the second largest share of greenhouse gas emissions. Approximately 62 percent of our electricity comes from burning fossil fuels, mostly coal and natural gas.iii
• Industry (23 per centum of 2019 greenhouse gas emissions) – Greenhouse gas emissions from industry primarily come from called-for fossil fuels for energy, besides as greenhouse gas emissions from certain chemical reactions necessary to produce goods from raw materials.
• Commercial and Residential (13 percent of 2019 greenhouse gas emissions) – Greenhouse gas emissions from businesses and homes arise primarily from fossil fuels burned for heat, the use of certain products that incorporate greenhouse gases, and the handling of waste.
• Agriculture (ten per centum of 2019 greenhouse gas emissions) – Greenhouse gas emissions from agriculture come from livestock such equally cows, agricultural soils, and rice production.
• Land Utilize and Forestry (12 percent of 2019 greenhouse gas emissions) – State areas tin can act as a sink (absorbing CO₂ from the atmosphere) or a source of greenhouse gas emissions. In the Us, since 1990, managed forests and other lands are a cyberspace sink, i.east., they have absorbed more CO₂ from the temper than they emit.

Emissions and Trends

Since 1990, gross U.South. greenhouse gas emissions have increased by 2 pct. From yr to twelvemonth, emissions can rise and fall due to changes in the economy, the price of fuel, and other factors. In 2019, U.S. greenhouse gas emissions decreased compared to 2018 levels. The decrease was primarily in CO₂ emissions from fossil fuel combustion which was a event of multiple factors, including a decrease in total free energy use and a connected shift from coal to less carbon intensive natural gas and renewables.

Annotation: All emission estimates from the Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990–2019.

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References

1. IPCC (2007). Summary for Policymakers. In: Climate Change 2007: The Concrete Science Footing. Contribution of Working Grouping I to the Fourth Assessment Written report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, One thousand. Manning, Z. Chen, Grand. Marquis, K.B. Averyt, Chiliad. Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United kingdom of great britain and northern ireland and New York, NY, Us.
2. IPCC (2007). Climatic change 2007: Mitigation. (PDF)(863 pp, 24MB) Contribution of Working Group Three to the Fourth Assessment Study of the Intergovernmental Console on Climate Change [B. Metz, O.R. Davidson, P.R. Bosch, R. Dave, L.A. Meyer (eds)], Cambridge Academy Press, Cambridge, United Kingdom and New York, NY, Usa.
3. U.S. Energy Information Assistants (2019). Electricity Explained - Nuts

Electricity Sector Emissions

Total Emissions in 2019 = vi,558 Million Metric Tons of CO2 equivalent. Percentages may not add upwards to 100% due to independent rounding.

* Land Use, Land-Use Change, and Forestry in the United States is a internet sink and removes approximately 12 per centum of these greenhouse gas emissions, this cyberspace sink is not shown in the above diagram. All emission estimates from the Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990–2019.

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The Electricity sector involves the generation, transmission, and distribution of electricity. Carbon dioxide (CO_two) makes upward the vast bulk of greenhouse gas emissions from the sector, but smaller amounts of marsh gas (CH₄) and nitrous oxide (Northward_iiO) are also emitted. These gases are released during the combustion of fossil fuels, such as coal, oil, and natural gas, to produce electricity. Less than 1 percent of greenhouse gas emissions from the sector come from sulfur hexafluoride (SF₆), an insulating chemic used in electricity manual and distribution equipment.

Greenhouse Gas Emissions in the Electricity Sector by Fuel Source

Coal combustion is more than carbon intensive than burning natural gas or petroleum for electricity. Although coal use accounted for about 61 percent of CO₂ emissions from the sector, it represented just 24 percent of the electricity generated in the United States in 2019. Natural gas use accounted for 37 percent of electricity generation in 2019, and petroleum utilize accounted for less than one percentage. The remaining generation in 2019 came from non-fossil fuel sources, including nuclear (20 percent) and renewable energy sources (18 percent), which include hydroelectricity, biomass, wind, and solar.1 Most of these non-fossil sources, such as nuclear, hydroelectric, wind, and solar, are non-emitting.

Emissions and Trends

In 2019, the electricity sector was the 2d largest source of U.Due south. greenhouse gas emissions, accounting for 25 pct of the U.South. full. Greenhouse gas emissions from electricity accept decreased past nigh 12 percent since 1990 due to a shift in generation to lower- and non-emitting sources of electricity generation and an increase in finish-use energy efficiency.

All emission estimates from the Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990–2019.

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Greenhouse Gas Emissions past Electricity End-Employ

Percentages may not add together upward to 100% due to independent rounding. All emission estimates from the Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990–2019.

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Electricity is used past other sectors—in homes, businesses, and factories. Therefore, it is possible to attribute the greenhouse gas emissions from electricity generation to the sectors that use the electricity. Looking at greenhouse gas emissions by end-employ sector tin can help united states of america understand free energy need across sectors and changes in energy apply over time.

When emissions from electricity generation are allocated to the industrial end-employ sector, industrial activities account for a much larger share of U.S. greenhouse gas emissions. Greenhouse gas emissions from commercial and residential buildings besides increase substantially when emissions from electricity end-employ are included, due to the relatively big share of electricity use (east.1000., heating, ventilation, and air-conditioning; lighting; and appliances) in these sectors. The transportation sector currently has a relatively low per centum of electricity use but it is growing due to the use of electric and plug-in vehicles.

Reducing Emissions from Electricity

At that place are a variety of opportunities to reduce greenhouse gas emissions associated with electricity generation, manual, and distribution. The table below categorizes these opportunities and provides examples. For a more comprehensive list, see Chapter 7 (PDF)(88 pp, three.6MB) of the Contribution of Working Group III to the Fifth Cess Report of the Intergovernmental Panel on Climate change.²

Example Reduction Opportunities for the Electricity Sector

Type	How Emissions Are Reduced	Examples
Increased Efficiency of Fossil-fired Power Plants and Fuel Switching	Increasing the efficiency of existing fossil fuel-fired ability plants by using advanced technologies; substituting less carbon-intensive fuels; shifting generation from college-emitting to lower-emitting power plants.	Converting a coal-fired boiler to use of natural gas, or co-firing natural gas. Converting a single-bicycle gas turbine into a combined-cycle turbine. Shifting dispatch of electrical generators to lower-emitting units or ability plants.
Renewable Energy	Using renewable energy sources rather than fossil fuel to generate electricity.	Increasing the share of total electricity generated from current of air, solar, hydro, and geothermal sources, besides every bit certain biofuel sources, through the addition of new renewable free energy generating capacity.
Increased End-Employ Free energy Efficiency	Reducing electricity utilize and peak demand by increasing energy efficiency and conservation in homes, businesses, and manufacture.	EPA's Free energy STAR® partners avoided over 330 million metric tons of greenhouse gases in 2018 solitary, helped Americans save over $35 billion in energy costs, and reduced electricity utilize by 430 billion kWh.
Nuclear Energy	Generating electricity from nuclear energy rather than the combustion of fossil fuels.	Extending the life of existing nuclear plants and edifice new nuclear generating capacity.
Carbon Capture and Sequestration (CCS)	Capturing CO2 as a byproduct of fossil fuel combustion earlier it enters the temper, transporting the CO2, injecting the CO2 deep secret at a carefully selected and suitable subsurface geologic formation where it is deeply stored.	Capturing COtwo from the stacks of a coal-fired power plant so transferring the COtwo via pipeline, injecting the COtwo deep cloak-and-dagger at a carefully selected and suitable nearby abandoned oil field where it is securely stored. Larn more about CCS.

References

1. U.S. Energy Information Assistants (2019). Electricity Explained - Basics.
2. IPCC (2014). Climate Change 2014: Mitigation of Climatic change (PDF) (1454 pp, 50MB). Contribution of Working Grouping 3 to the 5th Assessment Written report of the Intergovernmental Panel on Climate Modify [Edenhofer, O., R. Pichs-Madruga, Y. Sokona, E. Farahani, S. Kadner, G. Seyboth, A. Adler, I. Baum, S. Brunner, P. Eickemeier, B. Kriemann, J. Savolainen, S. Schlömer, C. von Stechow, T. Zwickel and J.C. Minx (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.

Transportation Sector Emissions

Total Emissions in 2019 = 6,558 1000000 Metric Tons of CO2 equivalent. Percentages may non add up to 100% due to independent rounding.

* Land Use, Land-Use Change, and Forestry in the United States is a net sink and removes approximately 12 percent of these greenhouse gas emissions, this net sink is not shown in the to a higher place diagram. All emission estimates from the Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990–2019.

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The Transportation sector includes the movement of people and goods by cars, trucks, trains, ships, airplanes, and other vehicles. The majority of greenhouse gas emissions from transportation are carbon dioxide (CO_two) emissions resulting from the combustion of petroleum-based products, like gasoline, in internal combustion engines. The largest sources of transportation-related greenhouse gas emissions include passenger cars, medium- and heavy-duty trucks, and lite-duty trucks, including sport utility vehicles, pickup trucks, and minivans. These sources business relationship for over one-half of the emissions from the transportation sector. The remaining greenhouse gas emissions from the transportation sector come up from other modes of transportation, including commercial aircraft, ships, boats, and trains, as well equally pipelines and lubricants.

Relatively minor amounts of methane (CH₄) and nitrous oxide (Due north₂O) are emitted during fuel combustion. In improver, a small corporeality of hydrofluorocarbon (HFC) emissions are included in the Transportation sector. These emissions result from the use of mobile air conditioners and refrigerated transport.

Emissions and Trends

In 2019, greenhouse gas emissions from transportation deemed for about 29 per centum of total U.S. greenhouse gas emissions, making it the largest contributor of U.S. greenhouse gas emissions. In terms of the overall trend, from 1990 to 2019, total transportation emissions accept increased due, in large part, to increased demand for travel. The number of vehicle miles traveled (VMT) by light-duty motor vehicles (passenger cars and light-duty trucks) increased past 48 percentage from 1990 to 2019, every bit a event of a confluence of factors including population growth, economic growth, urban sprawl, and periods of depression fuel prices. Between 1990 and 2004, average fuel economy among new vehicles sold annually declined, every bit sales of light-duty trucks increased. Starting in 2005, average new vehicle fuel economy began to increase while lite-duty VMT grew but modestly for much of the period. Average new vehicle fuel economy has improved almost every twelvemonth since 2005 slowing the rate of increase of CO_ii emissions, and the truck share is about 56 percent of new vehicles in model year 2019.

Learn more virtually Greenhouse Gas Emissions from Transportation.

Emissions involved in the consumption of electricity for transportation activities are included above, but not shown separately (as was done for other sectors). These indirect emissions are negligible, bookkeeping for less than i pct of the total emissions shown in the graph. All emission estimates from the Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990–2019.

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Reducing Emissions from Transportation

At that place are a diversity of opportunities to reduce greenhouse gas emissions associated with transportation. The table shown below categorizes these opportunities and provides examples. For a more comprehensive list, see Chapter eight of the Contribution of Working Group Three to the 5th Assessment Report of the Intergovernmental Panel on Climatic change.ⁱ

Examples of Reduction Opportunities in the Transportation Sector

Type	How Emissions Are Reduced	Examples
Fuel Switching	Using fuels that emit less CO2 than fuels currently beingness used. Alternative sources can include biofuels; hydrogen; electricity from renewable sources, such equally wind and solar; or fossil fuels that are less CO2-intensive than the fuels that they replace. Acquire more than about Green Vehicles and Alternative and Renewable Fuels.	Using public buses that are fueled past compressed natural gas rather than gasoline or diesel fuel. Using electrical or hybrid automobiles, provided that the energy is generated from lower-carbon or not-fossil fuels. Using renewable fuels such as depression-carbon biofuels.
Improving Fuel Efficiency with Advanced Design, Materials, and Technologies	Using advanced technologies, design, and materials to develop more fuel-efficient vehicles. Larn about EPA's vehicle greenhouse gas rules.	Developing advanced vehicle technologies such as hybrid vehicles and electric vehicles, that can shop free energy from braking and use it for power later. Reducing the weight of materials used to build vehicles. Reducing the aerodynamic resistance of vehicles through better shape pattern.
Improving Operating Practices	Adopting practices that minimize fuel utilize. Improving driving practices and vehicle maintenance. Acquire about how the freight transportation industry tin reduce emissions through EPA's SmartWay Program.	Reducing the average taxi time for aircraft. Driving sensibly (fugitive rapid acceleration and braking, observing the speed limit). Reducing engine-idling. Improved voyage planning for ships, such as through improved weather routing, to increase fuel efficiency.
Reducing Travel Demand	Employing urban planning to reduce the number of miles that people drive each day. Reducing the need for driving through travel efficiency measures such as commuter, biking, and pedestrian programs. Larn about EPA's Smart Growth Program.	Building public transportation, sidewalks, and wheel paths to increment lower-emission transportation choices. Zoning for mixed apply areas, then that residences, schools, stores, and businesses are close together, reducing the need for driving.

References

1. IPCC (2014). Climate Alter 2014: Mitigation of Climatic change (PDF) (1454 pp, 50 MB). Contribution of Working Grouping III to the Fifth Assessment Report of the Intergovernmental Panel on Climate change [Edenhofer, O., R. Pichs-Madruga, Y. Sokona, E. Farahani, South. Kadner, Grand. Seyboth, A. Adler, I. Baum, S. Brunner, P. Eickemeier, B. Kriemann, J. Savolainen, S. Schlömer, C. von Stechow, T. Zwickel and J.C. Minx (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, United states of america.

Manufacture Sector Emissions

Total Emissions in 2019 = vi,558 Million Metric Tons of CO2 equivalent. Percentages may not add up to 100% due to independent rounding.

* Land Use, Land-Utilize Change, and Forestry in the United states is a cyberspace sink and removes approximately 12 percentage of these greenhouse gas emissions, this internet sink is not shown in the to a higher place diagram. All emission estimates from the Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990–2019.

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The Industry sector produces the goods and raw materials we apply every day. The greenhouse gases emitted during industrial production are split into ii categories: direct emissions that are produced at the facility, and indirect emissions that occur off site, but are associated with the facility's use of electricity.

Directly emissions are produced past burning fuel for power or heat, through chemic reactions, and from leaks from industrial processes or equipment. Virtually direct emissions come from the consumption of fossil fuels for free energy. A smaller corporeality of straight emissions, roughly one 3rd, come from leaks from natural gas and petroleum systems, the utilise of fuels in production (east.k., petroleum products used to brand plastics), and chemical reactions during the production of chemicals, iron and steel, and cement.

Indirect emissions are produced by burning fossil fuel at a power plant to brand electricity, which is then used by an industrial facility to power industrial buildings and machinery.

More data nearly facility-level emissions from large industrial sources is available through EPA'south Greenhouse Gas Reporting Program'southward information publication tool. National-level information about emissions from industry as a whole can be institute in the sections on Fossil Fuel Combustion and the Industrial Processes chapter in the Inventory of U.Southward. Greenhouse Gas Emissions and Sinks.

Emissions and Trends

In 2019, direct industrial greenhouse gas emissions accounted for 23 percent of total U.Southward. greenhouse gas emissions, making information technology the third largest correspondent to U.S. greenhouse gas emissions, after the Transportation and Electricity sectors. Including both direct emissions and indirect emissions associated with electricity utilize, industry'southward share of full U.S. greenhouse gas emissions in 2019 was 30 per centum, making it the largest correspondent of greenhouse gases of any sector. Total U.S. greenhouse gas emissions from manufacture, including electricity, accept declined by 16 percent since 1990.

All emission estimates from the Inventory of U.Southward. Greenhouse Gas Emissions and Sinks: 1990–2019.

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Reducing Emissions from Industry

There are a broad variety of industrial activities that cause greenhouse gas emissions, and many opportunities to reduce them. The table shown below provides some examples of opportunities for industry to reduce emissions. For a more than comprehensive list, see Chapter ten of the Contribution of Working Group Iii to the Fifth Assessment Report of the Intergovernmental Panel on Climatic change. ¹

Examples of Reduction Opportunities for the Industry Sector

Blazon	How Emissions Are Reduced	Examples
Energy Efficiency	Upgrading to more efficient industrial technology. EPA's Energy STAR® program helps industries become more energy-efficient.	Identifying the ways that manufacturers tin can utilise less energy to calorie-free and heat factories or to run equipment.
Fuel Switching	Switching to fuels that issue in less CO2 emissions merely the same amount of energy, when combusted.	Using natural gas instead of coal to run machinery.
Recycling	Producing industrial products from materials that are recycled or renewable, rather than producing new products from raw materials.	Using scrap steel and scrap aluminum as opposed to smelting new aluminum or forging new steel.
Grooming and Awareness	Making companies and workers aware of the steps to reduce or forestall emissions leaks from equipment. EPA has a variety of voluntary programs that provide resource for training and other steps for reducing emissions. EPA supports programs for the aluminum, semiconductor, and magnesium industries.	Instituting handling policies and procedures for perfluorocarbons (PFCs), hydrofluorocarbons (HFCs), and sulfur hexafluoride (SF6) that reduce occurrences of accidental releases and leaks from containers and equipment.

References

1. IPCC (2014). Climate change 2014: Mitigation of Climatic change (PDF) (1454 pp, 50 MB). Contribution of Working Group 3 to the Fifth Assessment Study of the Intergovernmental Console on Climate change [Edenhofer, O., R. Pichs-Madruga, Y. Sokona, Due east. Farahani, S. Kadner, K. Seyboth, A. Adler, I. Baum, South. Brunner, P. Eickemeier, B. Kriemann, J. Savolainen, Due south. Schlömer, C. von Stechow, T. Zwickel and J.C. Minx (eds.)]. Cambridge University Press, Cambridge, United kingdom of great britain and northern ireland and New York, NY, USA.

Commercial and Residential Sector Emissions

Total Emissions in 2019 = 6,558 Million Metric Tons of CO2 equivalent. Percentages may not add up to 100% due to contained rounding.

* Country Utilise, Land-Use Change, and Forestry in the Us is a net sink and removes approximately 12 per centum of these greenhouse gas emissions, this net sink is not shown in the above diagram. All emission estimates from the Inventory of U.South. Greenhouse Gas Emissions and Sinks: 1990–2019.

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The residential and commercial sectors include all homes and commercial businesses (excluding agricultural and industrial activities). Greenhouse gas emissions from this sector come from direct emissions including fossil fuel combustion for heating and cooking needs, management of waste and wastewater, and leaks from refrigerants in homes and businesses equally well equally indirect emissions that occur offsite simply are associated with use of electricity consumed by homes and businesses.

Direct emissions are produced from residential and commercial activities in a diverseness of ways:

• Combustion of natural gas and petroleum products for heating and cooking needs emits carbon dioxide (CO₂), marsh gas (CH₄), and nitrous oxide (Due north₂O). Emissions from natural gas consumption represent 80 percentage of the directly fossil fuel CO₂ emissions from the residential and commercial sectors in 2019. Coal consumption is a small component of energy use in both of these sectors.
• Organic waste sent to landfills emits CH₄.
• Wastewater treatment plants emit CH₄ and N₂O.
• Anaerobic digestion at biogas facilities emits CH₄.
• Fluorinated gases (mainly hydrofluorocarbons, or HFCs) used in air-conditioning and refrigeration systems tin can be released during servicing or from leaking equipment.

Indirect emissions are produced by called-for fossil fuel at a power establish to make electricity, which is and then used in residential and commercial activities such as lighting and for appliances.

More national-level information about emissions from the residential and commercial sectors can be found in the U.S. Inventory'southward Free energy and Trends capacity.

Emissions and Trends

In 2019, direct greenhouse gas emissions from homes and businesses accounted for 13 percent of total U.S. greenhouse gas emissions. Greenhouse gas emissions from homes and businesses vary from yr to year oftentimes correlated with seasonal fluctuations in free energy employ caused primarily by atmospheric condition atmospheric condition. Total residential and commercial greenhouse gas emissions, including directly and indirect emissions, in 2019 accept increased by 3 percent since 1990. Greenhouse gas emissions from on-site straight emissions in homes and businesses have increased by viii per centum since 1990. Additionally, indirect emissions from electricity use by homes and businesses increased from 1990 to 2007, but accept decreased since then to approximately 1990 levels in 2019.

All emission estimates from the Inventory of U.Southward. Greenhouse Gas Emissions and Sinks: 1990–2019.

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Reducing Emissions from Homes and Businesses

The table shown beneath provides some examples of opportunities to reduce emissions from homes and businesses. For a more comprehensive list of options and a detailed cess of how each option affects different gases, see Chapter 9 and Chapter 12 of the Contribution of Working Group III to the Fifth Cess Report of the Intergovernmental Console on Climate Modify.

Examples of Reduction Opportunities in the Residential and Commercial Sector

Blazon	How Emissions Are Reduced	Examples
Homes and Commercial Buildings	Reducing free energy use through energy efficiency.	Homes and commercial buildings utilize large amounts of energy for heating, cooling, lighting, and other functions. "Green building" techniques and retrofits can permit new and existing buildings to use less energy to achieve the same functions, leading to fewer greenhouse gas emissions. Techniques to improve building free energy efficiency include better insulation; more than energy-efficient heating, cooling, ventilation, and refrigeration systems; efficient fluorescent lighting; passive heating and lighting to take advantage of sunlight; and the purchase of energy-efficient appliances and electronics. Learn more about Free energy STAR®.
Wastewater Handling	Making water and wastewater systems more than energy-efficient.	Drinking water and wastewater systems account for approximately 2 percent of energy utilisation in the United States. Past incorporating free energy efficiency practices into their water and wastewater institute, municipalities and utilities can save 15 to 30 percent in free energy use. Acquire more near Energy Efficiency for Water and Wastewater Utilities.
Waste Direction	Reducing solid waste sent to landfills. Capturing and using methyl hydride produced in current landfills.	Landfill gas is the natural byproduct of the decomposition of solid waste in landfills. It primarily consists of CO2 and CH4. Well established, depression-cost methods to reduce greenhouse gases from consumer waste matter exist, including recycling programs, waste matter reduction programs, and landfill marsh gas capture programs. Learn about WARM, EPA's Waste matter Reduction Model. Learn about EPA's Landfill Methane Outreach Program, which promotes the recovery and utilise of landfill gas.
Air conditioning and Refrigeration	Reducing leakage from air conditioning and refrigeration equipment. Using refrigerants with lower global warming potentials.	Commonly used refrigerants in homes and businesses include ozone-depleting hydrochlorofluorocarbon (HCFC) refrigerants, often HCFC-22, and blends consisting entirely or primarily of hydrofluorocarbons (HFCs), both of which are potent greenhouse gases. In contempo years there have been several advancements in ac and refrigeration applied science that can help food retailers reduce both refrigerant charges and refrigerant emissions. Acquire more about EPA's GreenChill Programme to reduce greenhouse gas emissions from supermarkets.

Agronomics Sector Emissions

Total Emissions in 2019 = 6,558 Million Metric Tons of CO2 equivalent. Percentages may not add up to 100% due to independent rounding.

* Land Use, Country-Use Change, and Forestry in the United States is a net sink and removes approximately 12 percent of these greenhouse gas emissions, this cyberspace sink is not shown in the higher up diagram. All emission estimates from the Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990–2019.

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Agricultural activities — ingather and livestock production for food — contribute to emissions in a variety of ways:

• Various management practices on agricultural soils can pb to increased availability of nitrogen in the soil and effect in emissions of nitrous oxide (N_iiO). Specific activities that contribute to Northward_twoO emissions from agronomical lands include the awarding of synthetic and organic fertilizers, the growth of nitrogen-fixing crops, the drainage of organic soils, and irrigation practices. Management of agricultural soils accounts for merely over one-half of the greenhouse gas emissions from the Agriculture economic sector.*
• Livestock, specially ruminants such as cattle, produce methane (CH_iv) equally part of their normal digestive processes. This process is called enteric fermentation, and it represents over a quarter of the emissions from the Agriculture economical sector.
• The way in which manure from livestock is managed likewise contributes to CH₄ and Northward_twoO emissions. Different manure handling and storage methods affect how much of these greenhouse gases are produced. Manure direction accounts for about 12 percent of the full greenhouse gas emissions from the Agronomics economical sector in the United States.
• Smaller sources of agricultural emissions include CO_two from liming and urea application, CH₄ from rice cultivation, and called-for crop residues, which produces CH_four and North₂O.

More than information about emissions from agriculture can exist constitute in the agriculture affiliate in the Inventory of U.Due south. Greenhouse Gas Emissions and Sinks.

* Management of croplands and grasslands can also atomic number 82 to emissions or sequestration of carbon dioxide (CO₂). However, these emissions and removals are included under the Land Use, Land-Utilise Change, and Forestry sector.

Emissions and Trends

In 2019, greenhouse gas emissions from the agriculture economic sector accounted for ten percent of full U.Southward. greenhouse gas emissions. Greenhouse gas emissions from agronomics have increased past 12 percent since 1990. Drivers for this increment include a 9 percentage increase in N₂O from management of soils, along with a 60 per centum growth in combined CH₄ and North_twoO emissions from livestock manure direction systems, reflecting the increased use of emission-intensive liquid systems over this time flow. Emissions from other agricultural sources have generally remained apartment or inverse past a relatively small corporeality since 1990.

All emission estimates from the Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990–2019.

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Reducing Emissions from Agronomics

The table shown below provides some examples of opportunities to reduce emissions from agriculture. For a more comprehensive list of options and a detailed assessment of how each selection affects unlike gases, see Chapter 11 of the Contribution of Working Grouping III to the 5th Assessment Report of the Intergovernmental Console on Climate Alter.

Examples of Reduction Opportunities for the Agriculture Sector

Type	How Emissions Are Reduced	Examples
Land and Ingather Management	Adjusting the methods for managing land and growing crops.	Fertilizing crops with the appropriate amount of nitrogen required for optimal crop product, since over-application of nitrogen tin can lead to college nitrous oxide emissions without enhancing crop product. Draining water from wetland rice soils during the growing flavor to reduce methane emissions.
Livestock Management	Adjusting feeding practices and other management methods to reduce the corporeality of methane resulting from enteric fermentation.	Improving pasture quality to increase fauna productivity, which can reduce the amount of marsh gas emitted per unit of creature product. Likewise, increased productivity in livestock tin can be introduced through improved breeding practices.
Manure Management	Controlling the way in which manure decomposes to reduce nitrous oxide and methyl hydride emissions. Capturing methyl hydride from manure decomposition to produce renewable energy.	Treatment manure as a solid or depositing it on pasture rather than storing it in a liquid-based system such as a lagoon would likely reduce methane emissions but may increment nitrous oxide emissions. Storing manure in anaerobic lagoons to maximize methane production and and then capturing the methane to use as an energy substitute for fossil fuels. For more than data on capturing methyl hydride from manure management systems, see EPA's AgSTAR Plan, a voluntary outreach and education plan that promotes recovery and use of methyl hydride from beast manure.

Land Use, Land-Use Change, and Forestry Sector Emissions and Sequestration

Plants blot carbon dioxide (CO_ii) from the atmosphere equally they grow, and they store some of this carbon as aboveground and belowground biomass throughout their lifetime. Soils and dead organic matter/litter tin besides store some of the carbon from these plants depending on how the soil is managed and other environmental conditions (eastward.g., climate). This storage of carbon in plants, expressionless organic affair/litter and soils is called biological carbon sequestration. Because biological sequestration takes CO₂ out of the atmosphere and stores information technology in these carbon pools, it is also called a carbon "sink."

Emissions or sequestration of CO_two, likewise as emissions of CH₄ and N_twoO can occur from management of lands in their current use or as lands are converted to other land uses. Carbon dioxide is exchanged between the atmosphere and the plants and soils on land, for example, as cropland is converted into grassland, as lands are cultivated for crops, or as forests grow. In addition, using biological feedstocks (such equally energy crops or wood) for purposes such as electricity generation, as inputs to processes that create liquid fuels, or as building materials tin lead to emissions or sequestration.*

In the United States overall, since 1990, Land Use, Land-Employ Modify, and Forestry (LULUCF) activities have resulted in more removal of CO₂ from the atmosphere than emissions. Considering of this, the LULUCF sector in the United States is considered a internet sink, rather than a source, of CO_ii over this time-period. In many areas of the earth, the opposite is true, particularly in countries where large areas of wood land are cleared, oft for conversion to agricultural purposes or for settlements. In these situations, the LULUCF sector can be a net source of greenhouse gas emissions.

• More national-level information about land use, land-use modify, and forestry is available from the State Use, Land-Use Alter, and Forestry affiliate in the Inventory of U.South. Greenhouse Gas Emissions and Sinks. For more information on emissions and sequestration from forest state and urban trees in settlement areas, see also the USFS Resources Update.
• For more information about global emissions from country use and forestry activities, run across EPA's Global Greenhouse Gas emissions page and the Contribution of Working Group Three to the Fifth Assessment Report of the Intergovernmental Panel on Climate change.

* Emissions and sequestration of CO₂ are presented under the Land Utilize, Land-Apply Modify, and Forestry sector in the Inventory. Emissions of marsh gas (CH₄) and nitrous oxide (Northward₂O) also occur as a result of country use and direction activities in the LULUCF sector. Other emissions from CH₄ and North₂O are likewise presented in the Free energy sector.

Emissions and Trends

In 2019, the net CO₂ removed from the atmosphere from the LULUCF sector was 12 percent of total U.S. greenhouse gas emissions. Between 1990 and 2019, total carbon sequestration in the LULUCF sector decreased past 11 percent, primarily due to a subtract in the rate of net carbon accumulation in forests and cropland, likewise as an increment in CO₂ emissions from urbanization. Additionally, while episodic in nature, increased CO₂, CH₄ and N_twoO emissions from forest fires have also occurred over the time series.

*Note: The LULUCF sector is a cyberspace "sink" of emissions in the United States (east.chiliad., more greenhouse gas emissions are sequestered than emitted from state use activities), so net greenhouse gas emissions from LULUCF are negative. All emission estimates from the Inventory of U.South. Greenhouse Gas Emissions and Sinks: 1990–2019. Larger image to save or print

Reducing Emissions and Enhancing Sinks from Land Utilise, Country-Use Change, and Forestry

In the LULUCF sector, opportunities exist to reduce emissions and increment the potential to sequester carbon from the atmosphere by enhancing sinks. The tabular array shown below provides some examples of opportunities for both reducing emissions and enhancing sinks. For a more comprehensive listing, meet Chapter 11 of the Contribution of Working Group III to the Fifth Cess Study of the Intergovernmental Panel on Climate Alter.

Examples of Reduction Opportunities in the LULUCF Sector

Type	How Emissions Are Reduced or Sinks Are Enhanced	Examples
Modify in Uses of Land	Increasing carbon storage by using country differently or maintaining carbon storage by avoiding country deposition.	Tree planting and minimizing the conversion of forest state to other land uses, such as settlements, croplands, or grasslands.
Changes in Country Direction Practices	Improving direction practices on existing land-employ types.	Utilizing reduced cultivation practices on cropland and improved grazing management practices on grassland. Planting afterwards natural or human-induced wood disturbances to accelerate vegetation growth and minimize soil carbon losses.

Source: https://www.epa.gov/ghgemissions/sources-greenhouse-gas-emissions

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