Cars In America: Major Polluters Or Not?

Cars are a major contributor to air pollution and the health consequences it causes worldwide. In the United States, the transportation sector is responsible for about 31% of total US energy-related carbon dioxide emissions, with motor gasoline and diesel fuel consumption accounting for 22% and 9% respectively. A typical passenger vehicle emits about 4.6 metric tons of carbon dioxide per year, and the average gasoline vehicle emits about 400 grams of CO2 per mile. The US transportation sector is also responsible for about 39% of total US energy-related CO2 emissions. Marginalized communities in US cities are often located near freight centres and heavily travelled roadways, and as a result, Asian Americans, Black people, and Latinos are exposed to higher levels of air pollution than White people.

Cars, trucks, and buses powered by fossil fuels are major contributors to air pollution

The burning of fossil fuels like gasoline and diesel releases carbon dioxide, a greenhouse gas, into the atmosphere. This leads to the buildup of carbon dioxide and other greenhouse gases, causing the Earth's atmosphere to warm and resulting in climate change. Cars, trucks, and buses produce air pollution throughout their life cycle, including during vehicle operation and fuel production. The pollutants emitted from these vehicles include Volatile Organic Compounds (VOCs), nitrogen oxides (NOx), and carbon monoxide (CO). VOCs react with nitrogen oxides in the presence of sunlight to form ground-level ozone, a key ingredient in smog that irritates the respiratory system. NOx can cause lung irritation and weaken defenses against respiratory infections, while carbon monoxide is a colorless, odorless, and poisonous gas formed by the combustion of fossil fuels.

The impact of air pollution from cars, trucks, and buses is not evenly distributed across the population. Studies have shown that exposure to harmful particulate matter air pollution, known as PM2.5, varies among different racial groups in the US. Asian Americans, for instance, are exposed to 34% higher PM2.5 concentrations than the average person in the US, while Black and Latino individuals experience concentrations that are 24% and 23% higher, respectively. This disparity is also evident at the community level, with census tracts having higher proportions of people of color being more exposed to PM2.5 pollution from vehicles.

To address these issues, the Environmental Protection Agency (EPA) and the Department of Transportation (DOT) have implemented regulations and initiatives to reduce greenhouse gas emissions and improve fuel economy in the transportation sector. These include setting standards for automakers, providing consumers with information on fuel economy and emissions, and promoting the adoption of clean vehicle and fuel technologies.

Vehicle emissions come in two main types: carbon dioxide and air pollution

Vehicle emissions are a significant contributor to air pollution and climate change. The two main types of emissions from vehicles are carbon dioxide (CO2) and air pollutants. Carbon dioxide is a greenhouse gas that accumulates in the atmosphere, trapping heat and contributing to global warming. The amount of CO2 emitted by a vehicle depends on the type of fuel used and the vehicle's fuel efficiency. Gasoline and diesel engines emit different amounts of CO2, with diesel engines typically emitting more. The age and condition of the vehicle also play a role, as older cars tend to be less fuel-efficient and thus emit more CO2. While electric vehicles (EVs) produce zero direct CO2 emissions, the electricity used to power them may still come from fossil fuels, resulting in indirect emissions.

Air pollution from vehicles takes several forms, including nitrogen oxides (NOx), volatile organic compounds (VOCs), carbon monoxide (CO), and particulate matter (PM). These pollutants have direct impacts on human health and the environment. NOx and VOCs react with sunlight to form ground-level ozone, a major component of smog, which irritates the lungs and exacerbates respiratory conditions. Carbon monoxide reduces the blood's ability to carry oxygen, leading to fatigue and increasing the risk of heart disease. Particulate matter, especially the fine particles produced by diesel engines, can penetrate deep into the lungs and even enter the bloodstream, causing or worsening respiratory and cardiovascular problems.

The contribution of vehicles to air pollution varies across America. A report by the American Lung Association, titled "State of the Air 2022," found that more than 137 million people lived in counties with failing grades for ozone or particle pollution, with California's Los Angeles-Long Beach area topping the list for ozone pollution. However, the report also highlighted improvements, with 15 cities experiencing their cleanest-ever years for ozone levels. Vehicle emissions standards and technological advancements have played a role in reducing air pollution from vehicles, but there are still areas of concern, particularly in densely populated urban areas.

Reducing vehicle emissions is crucial to improving air quality and mitigating climate change. This can be achieved through various means, including improving fuel efficiency, transitioning to electric or other low-emission vehicles, and promoting alternative transportation methods such as public transit, walking, and biking. Incentivizing the adoption of electric vehicles, improving charging infrastructure, and implementing stricter emissions standards can also help reduce vehicle emissions. Additionally, addressing emissions from heavy-duty vehicles, such as trucks and buses, is essential, as they contribute disproportionately to air pollution due to their higher emissions rates and longer operational lifetimes.

The US transportation sector emitted 1,489 million metric tons of CO2 in 2023

The transportation sector is a significant contributor to the United States' carbon footprint. In 2023, the US transportation sector emitted 1,489 million metric tons of CO2, accounting for about 31% of total US energy-related carbon dioxide emissions. This figure includes emissions from motor gasoline consumption, which made up about 22% (1,033 million metric tons), and diesel fuel consumption, which accounted for approximately 9% (455 million metric tons). The US transportation sector's emissions are not limited to these sources, as they also encompass other fuels and modes of transportation.

The transportation sector has surpassed the electric power sector in emissions, now constituting two-fifths of domestic emissions from burning fossil fuels. This is largely due to the high number of personal vehicles on the road, such as cars, light-duty trucks, and motorcycles, which were responsible for about 58% of emissions in the transportation sector in 2019. When combined with commercial trucks and buses, which made up 25% of emissions, it's clear that road vehicles are the primary source of transportation-related emissions.

To address this issue, the EPA has implemented more stringent standards for model years 2023 to 2026, aiming to reduce emissions from vehicles. Manufacturers can meet these standards by producing alternative-fuel vehicles, improving air-conditioning systems, and adopting technologies that enhance vehicle operating efficiency. Additionally, the rise in electric vehicle sales is a positive step towards reducing transportation emissions, as battery costs decrease and charging infrastructure improves.

While the US transportation sector's emissions have seen a slight increase in recent years, it is important to note that the country is the largest contributor to global transportation emissions, accounting for almost a quarter of the world's total. This highlights the urgent need for continued efforts to reduce emissions and transition to more sustainable transportation solutions.

Marginalised communities are often located near freight centres and heavily travelled roadways

Even today, communities of colour and low-income neighbourhoods are disproportionately affected by pollution from nearby freight centres and busy roads. This is due to a variety of factors, including the historical legacy of redlining, the lack of political power and representation of these communities, and the fact that polluters often choose locations in marginalised areas because they face fewer regulatory hurdles and community objections. As a result, residents in these areas are exposed to higher levels of air and noise pollution, leading to a range of health issues such as respiratory problems, heart disease, and mental health impacts.

The pollution from freight centres and heavily travelled roadways can come in many forms, including air pollution, water pollution, and soil contamination. Air pollution from diesel trucks and idling cars can include particulate matter, nitrogen oxides, and volatile organic compounds, which have been linked to respiratory and cardiovascular issues. Noise pollution from constant traffic can also have significant impacts on mental health and well-being. Additionally, the pollution from these sources can contribute to climate change, creating a feedback loop where the most vulnerable communities are impacted first and worst.

Marginalised communities located near these pollution sources often face a range of social and economic challenges as well. The constant traffic and pollution can lead to a decrease in property values and a lack of investment in the area, perpetuating a cycle of poverty, and making it difficult for residents to move to less polluted neighbourhoods. Additionally, the health impacts of pollution can lead to higher medical costs and reduced productivity, further exacerbating existing social and economic inequalities.

Addressing this issue requires a multifaceted approach that tackles both the immediate pollution problem and the underlying social and racial injustices that have led to these communities being marginalised in the first place. This includes implementing stricter emissions standards and pollution controls, investing in green infrastructure and renewable energy sources, and prioritising the relocation of freight centres and major roadways away from residential areas. Additionally, providing marginalised communities with the resources and representation needed to advocate for themselves and hold polluters accountable is crucial to creating long-term, sustainable solutions that protect the health and well-being of all community members.

The EPA provides resources to help consumers identify vehicles that save money and reduce emissions

The Environmental Protection Agency (EPA) has taken a significant step towards tackling tailpipe pollution and addressing the climate crisis by encouraging the shift to clean cars and trucks. The EPA provides various resources to help consumers identify vehicles that save money and reduce emissions.

One such resource is the Green Vehicle Guide, an online tool that provides information on fuel economy and fuel costs. It also includes ratings on greenhouse gas emissions and smog-forming pollutants, enabling consumers to make informed choices about their vehicle purchases. Additionally, the EPA has developed the SmartWay program, which identifies the top-performing vehicles in terms of fuel economy and emissions. The program assists consumers in making environmentally friendly choices, reducing their carbon footprint, and saving money on fuel costs.

The EPA also collaborates with other organizations, such as the Department of Energy (DOE), to provide websites like fueleconomy.gov, which offers comprehensive information on fuel efficiency and transportation-related emissions. These resources empower consumers to select vehicles that not only reduce their environmental impact but also provide long-term cost savings.

Furthermore, the EPA evaluates and sets standards for greenhouse gas emissions from federal fleets. The 2007 Energy Independence and Security Act mandates that federal agencies acquire vehicles with low greenhouse gas emissions. The EPA assesses the emissions performance of these fleets annually, ensuring that federal agencies prioritize the purchase of high-performing, environmentally friendly vehicles. This initiative contributes to a greener federal fleet and sets a sustainable example for the nation.

By leveraging these resources, consumers can make informed decisions about their vehicle choices, contributing to both environmental sustainability and economic savings. The EPA's efforts to reduce emissions and combat climate change demonstrate a commitment to a cleaner and healthier future for all.

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