Carbon Emissions

Carbon emissions

Carbon emissions are human activities which amplify the greenhouse effect and contribute to climate change, predominantly via burning fossil fuels such as coal and oil.

Every individual, building, corporation and nation leaves behind their own carbon footprint. It reflects their choices of production and consumption. Direct or scope 1 emissions occur at the site producing goods or services directly.

Fossil Fuels

Fossil fuels (coal, oil and natural gas) are the primary contributor to global warming and other climate change. Their formation from ancient animal and plant remains dates back millions of years; when burned they release all their stored carbon as greenhouse gases into the air – acting like blankets around Earth to increase global warming further.

Fossil fuels must be extracted from the ground or seabed before they can be processed into energy that powers homes, factories and vehicles. Unfortunately, fossil fuels also contribute to air pollution with harmful side effects including particulate matter pollution that enters lungs causing diseases like lung cancer or polluting water supplies and soil resources.

Coal is one of the world’s most abundant fossil fuels and is mined either underground or from open-pit mines. Once mined, coal-fired power plants use it to generate electricity – emitting lots of carbon dioxide that’s bad for both their operations and for the environment.

Oil is a versatile liquid at room temperature that serves multiple functions. Pumped from underground or ocean floor reserves and transported by pipeline or truck to power plants for burning, it provides transportation energy as well as manufacturing needs.

While oil emits some greenhouse gases, it is significantly less harmful than coal due to it releasing less carbon dioxide into the atmosphere when burned and having fewer harmful side effects.

2022 projections predict an expected rise in carbon emissions from fossil fuels due to recovery from the Covid-19 pandemic, which saw increased air travel and activities, as well as lower prices for natural gas and renewables, leading to higher oil usage and rising carbon emissions.

Importantly, policies designed to reduce demand for fossil fuels can have an enormously positive effect on greenhouse gas emissions. For instance, policies mandating corn ethanol blends will help decrease demand for petroleum, which in turn decreases GHGs from this source. But without specific goals such as cutting emissions produced in production processes for these fossil fuels they will have only limited success in lowering GHGs emissions from production sites, leaving emissions unchecked.


One source of global carbon emissions comes from creating electricity and heat through fossil fuel-burning power plants – burning fossil fuels such as coal, oil, or natural gas – which emit greenhouse gases that blanket Earth with warmth from the sun and trap heat in. Cleaner forms of energy like wind or solar generation don’t emit any greenhouse gasses or pollutants when producing electricity for power generation purposes.

Power generation accounts for 28 percent of U.S. greenhouse gas emissions, with coal being the primary contributor at 37 percent. Although renewables have become an increasingly significant part of America’s electricity mix, fossil fuels still make up over 63% of our nation’s energy mix. Multiple laws and court cases provide authority for the Environmental Protection Agency (EPA) to monitor and regulate greenhouse gas emissions from power plants.

Energy sector greenhouse gas emissions in the US account for approximately 15% of emissions overall; electric power generation accounts for 25%. Since 1990, emissions from electricity production have declined approximately 15% due to switching to lower emitting sources and improving end use energy efficiency.

2021 saw domestic energy-related CO2 emissions grow 5% year over year, following an economic slowdown during COVID-19 pandemic. A surge in global economic activity was behind this increase.

A typical coal-fired power plant emits approximately 2,249 pounds of carbon per megawatt hour of electricity produced, while using gas combined cycle technology can drastically lower emissions to approximately 1,000 pounds per megawatt hour at older facilities. Nuclear and renewable energy power plants tend to emit lower levels of greenhouse gases, although both types can emit substantial quantities during construction and operations processes.

Another way of reducing electricity generation’s carbon footprint is through CO2 capture and storage at power plants, similar to how EPA’s ENERGY STAR program helps Americans save money and reduce carbon emissions through partnerships with private companies to improve home energy efficiency and lower utility bills. Carbon capture and storage (CCS), on the other hand, is an emerging technology used by coal-fired power plants to reduce emissions through taking measures such as collecting exhaust exhaust from their exhaust stack and transporting it via pipelines before injecting it deep underground geologic formation for long-term storage.


Transport emissions – including CO2 and other greenhouse gases – make up an immense proportion of global greenhouse emissions, most often when fossil fuels such as gasoline, diesel and jet fuel are burned. Other emissions sources can include natural gas, coal, petroleum products (including plastics), chemicals metals such as aluminum steel and minerals used in industrial processes and equipment.

Vehicles account for three-quarters of transportation sector carbon dioxide emissions in the United States, mostly coming from passenger cars and light trucks (such as SUVs, pickups trucks and minivans). Each gallon of gasoline consumed releases 20 pounds of CO2. Passenger rail transit, intercity buses and commercial air travel have significantly lower emission per passenger mile.

These emissions are highly unpredictable and may vary year to year depending on economic cycles and fuel costs, with changes to other sectors, such as electricity generation, potentially offsetting them.

World GDP has grown considerably over the past two decades, yet travel has only increased marginally and carbon emissions have not spiked as dramatically due to advances in vehicle fuel efficiency that have reduced CO2 per mile traveled. Unfortunately, these improvements only address part of the demand for additional travel caused by demographic trends and economic opportunity;

Reducing transportation emissions requires policies that address both demand and supply. This involves supporting more livable urban communities that offer public transit services as well as walking and biking paths, along with supporting innovations such as electric, autonomous and data-driven technologies.

Transportation emission reduction can help combat air pollution, which has been linked to numerous health conditions like heart disease and lung ailments. Studies suggest outdoor air pollution contributes to over 3.2 million early deaths every year globally, with urban areas seeing the majority of emissions reduction efforts. Industrial and electricity sectors often share energy sources and production processes which allow mitigation efforts that benefit all parties involved whereas transport emissions require participation by all nations involved for effective mitigation to occur.


Industry sectors produce goods and materials used by people worldwide every day, making them one of the primary contributors of carbon emissions. Their emissions can be broken down into two categories: direct and indirect emissions from production facilities while indirect emissions result from their energy use and resource consumption offsite. Direct emissions come mainly from using fossil fuels for heat/power purposes as well as chemical reactions associated with metal manufacturing (iron/steel), chemical manufacturing (minerals/petroleum), food/beverages manufacturing processes, or paper product manufacturing operations.

Industry emissions come primarily from energy consumption, such as electricity and natural gas usage. Combustion of fossil fuels at electric power plants contributes significantly to greenhouse gas emissions in the US.

Steps can be taken to lower emissions from industry sectors. These may include using higher quality equipment, decreasing energy use and switching to renewable power sources such as wind and solar. Furthermore, process improvements and alternative raw materials may significantly lower emissions; examples could include using recycled aluminum instead of producing new aluminum or using fly ash instead of high emitting coal clinker in cement production.

These strategies, and others, can be combined to form a holistic strategy for decarbonization of industry. By adopting such an approach, industry can continue its essential contributions while simultaneously reducing emissions and contributing to climate stability.

Residential and Commercial sectors represent the majority of nonelectric emissions in 2021, most notably from fossil fuel combustion for heating and cooling needs and leaks of refrigerants. Emissions can be decreased through installing energy-efficient appliances and lighting, upgrading old furnaces to modern boiler systems, using solar or wind power for both heating and electricity needs, taking advantage of smart growth programs to promote urban planning that makes walking, riding a bike or taking public transit easier as well as taking advantage of programs like smart growth which facilitate it.