Natural Gas And Air Pollution: Strategies For Mitigation

Natural gas is a fossil fuel that has been used for lighting since the 1790s. It is a major contributor to air pollution, water pollution, and climate change. The extraction, transportation, and combustion of natural gas can all result in the release of hazardous air pollutants, including methane, benzene, toluene, ethylbenzene, xylene, and hexane. These pollutants have been linked to adverse health effects, such as respiratory symptoms, cardiovascular disease, and cancer. While natural gas may produce fewer emissions than coal or petroleum products, it still contributes significantly to air pollution, and leaks can occur at any stage of its journey, from extraction to combustion. To mitigate the environmental and health impacts of natural gas, strict regulations, improved leak detection technology, and a transition to alternative energy sources are necessary.

Natural gas is a fossil fuel that emits pollution and contributes to climate change

Natural gas is a fossil fuel, formed from ancient plant material deposited and cooked over millions of years in an oxygen-poor environment by heat from the earth. It is a major contributor to air pollution, water pollution, and climate change. The process of extracting natural gas through hydraulic fracturing, or fracking, involves injecting water, sand, and chemicals into rock formations under high pressure to release the gas, which then flows into wells. This process has been used since the mid-20th century and has been criticised for its environmental impact.

The extraction and use of natural gas contribute to air pollution in several ways. Firstly, during the exploration and drilling stages, vegetation, soil, and wildlife may be disturbed, and air pollution may be produced. Additionally, the transportation and storage of natural gas can result in leaks, releasing methane and other harmful pollutants into the atmosphere. The US Environmental Protection Agency (EPA) estimates that methane emissions from natural gas systems and abandoned wells were responsible for about 33% of total US methane emissions in 2021.

Furthermore, natural gas used in homes has been found to contain hazardous air pollutants, including volatile organic compounds (VOCs) and chemicals like benzene, toluene, and hexane. These pollutants can have serious health impacts, including an increased risk of cancer. Leaks of natural gas in homes can go undetected due to the low odour of methane, and even small amounts of these pollutants can degrade indoor and outdoor air quality.

To address the issue of air pollution from natural gas, the EPA has proposed revisions to its Clean Air Act regulations, aiming to reduce methane and other harmful emissions from the oil and natural gas industry. State regulations could also play a role in mitigating natural gas leaks, with proposals for direct measurement of leaks and improved ventilation in homes. Additionally, the development of renewable natural gas (RNG), or biomethane, offers a potential alternative. RNG is produced from organic materials and can utilise the existing natural gas distribution system, providing a lower-emission option for vehicles.

Natural gas leaks at every stage of its journey, releasing methane into the atmosphere

Methane is a highly potent greenhouse gas, trapping more heat in the atmosphere per molecule than carbon dioxide (CO2). In the short term, over 10 to 20 years, methane is 80 to 100 times more harmful than CO2. As a result, methane is a significant contributor to global warming and climate change. The oil and gas industries are major methane producers, emitting methane during drilling, production, and other operations.

Natural gas leaks occur throughout the supply chain, starting at the wellhead. They can happen during and after well drilling, as well as from storage tanks, pipelines, and processing plants. Thousands of small natural gas leaks under city streets and sidewalks contribute to a major climate threat. These leaks can impact both indoor and outdoor air quality, as natural gas is used by appliances in close proximity to people.

To address natural gas leaks, gas utilities, regulators, and public officials must work to repair and prevent methane leaks. While utility companies are required to inspect their lines for safety and fix safety issues within a specified time, the current rules do not mandate the repair of all leaks. Additionally, the challenges of investing in major pipeline upgrades needed to prevent leaks exist. Advanced technologies, such as satellites, global positioning systems, and remote sensing devices, can help detect and measure large methane emissions, particularly super-emitter events.

Natural gas flaring produces CO2, carbon monoxide, and other harmful compounds

Natural gas flaring, or the burning of natural gas byproducts during the crude oil extraction process, produces CO2, carbon monoxide, sulfur dioxide, nitrogen oxides, and many other compounds. The specific chemical composition of these emissions depends on the chemical composition of the natural gas and how well it burns in the flare. Flaring is often chosen as an option by oil producers because it is not profitable to capture, transport, and process natural gas byproducts.

Flaring contributes to the release of large amounts of environmental pollutants, including volatile organic compounds, and has a noticeably negative impact on human health. A study in Iran found that flaring-induced emissions of benzene, toluene, ethylbenzene, and xylenes (BTEX) had adverse effects on respiratory health. Another study estimated that a 1% increase in the amount of flared natural gas in North Dakota would increase the respiratory-related hospital visitation rate by 0.73%.

Despite these negative impacts, flaring is considered safer than releasing natural gas into the air and results in lower overall greenhouse gas emissions because CO2 is not as strong a greenhouse gas as methane. Advanced technologies, such as satellites and 3-D and 4-D seismic technologies, can help discover natural gas reserves and reduce the number of wells drilled, thereby reducing air pollution from well drilling activities.

Well drilling and pipeline construction produce air pollution and disturb people and wildlife

Well drilling and the construction of pipelines can have a significant impact on air quality and the surrounding environment. Drilling a natural gas well often involves clearing and levelling the land around the site, which can disturb vegetation and soil. The process of drilling and operating wells also produces air pollution, with higher levels of pollutants found within a 2.5-mile radius, including toxic particulate matter (PM2.5), carbon monoxide, nitrous oxide, ozone, and volatile organic compounds (VOCs). These emissions can have severe health consequences for nearby residents, increasing the risk of adverse outcomes such as preterm birth, asthma, and heart disease.

The construction of pipelines, which are used to transport natural gas from wells, also contributes to air pollution. Laying pipelines typically requires clearing land to bury the pipes, and the engines used to run equipment and compressors produce air pollutants and noise. The disruption caused by drilling operations, including loud noises, human movement, and vehicle traffic, can also disturb wildlife, disrupting their communication, breeding, and nesting patterns. Power lines, well pads, fences, and roads associated with pipeline construction can further fragment habitats for many species.

To mitigate these impacts, it is essential to reduce fossil fuel development, especially on public lands, and transition to renewable energy sources such as solar and wind power. Stringent government regulations and industry standards are also necessary to ensure the safe handling, storage, and transportation of natural gas to prevent leaks and explosions. Additionally, advanced technologies, such as horizontal and directional drilling techniques, can help reduce the land area disturbed during well drilling, and the U.S. EPA has established guidelines to reduce methane and other harmful air pollutants from the natural gas industry.

Furthermore, the example of China's natural gas pipeline projects demonstrates that replacing conventional energy sources with natural gas can effectively reduce air pollution. These projects have facilitated the reduction of sulfur dioxide (SO2) emissions and improved daily air quality in connected cities. Similar initiatives can be implemented in other countries to combat air pollution and fulfill commitments to reducing carbon intensity.

Regulations and standards aim to ensure safe transportation, storage, and consumption of natural gas

The safe transportation, storage, and consumption of natural gas are ensured through strict government regulations and industry standards. Natural gas is a highly flammable fuel source, and leaks can lead to dangerous explosions. Additionally, natural gas is a significant contributor to air pollution, particularly when it is released or flared during the drilling process.

In the United States, the Department of Transportation's Office of Pipeline Safety is responsible for ensuring the safe transportation of natural gas through pipelines. The Pipeline and Hazardous Materials Safety Administration (PHMSA) establishes and enforces regulations for the safe movement of hazardous materials, including natural gas, by all modes of transportation. PHMSA also sets minimum safety standards for underground natural gas storage facilities (UNGSFs) to prevent accidents and protect the environment. These standards cover construction, operation, maintenance, and emergency response procedures.

The Federal Energy Regulatory Commission regulates the interstate natural gas market in the United States, while the National Energy Board fulfills a similar role in Canada. To prevent natural gas leaks, the U.S. Environmental Protection Agency (EPA) has established guidelines for the oil and natural gas industry to reduce methane and other harmful air pollutant emissions. The EPA also estimates that abandoned oil and natural gas wells contribute significantly to methane emissions.

To address the issue of natural gas flaring, which releases CO2, carbon monoxide, sulfur dioxide, and nitrogen oxides, advanced technologies such as horizontal and directional drilling techniques are being employed. These innovations reduce the number of wells needed and minimize the disturbance to the land, water, and wildlife during the exploration and extraction of natural gas. Overall, these regulations and standards are crucial in ensuring the safe and environmentally responsible transportation, storage, and consumption of natural gas.

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