Transportation's Pollution Volume: A Startling Reality Check

The transport sector is a major source of air pollution and the largest contributor to heat-trapping emissions in the United States. In 2020, transportation accounted for 27% to 28% of greenhouse gas emissions in the US, with 57% of these emissions coming from passenger cars and light-duty trucks. Heavy-duty vehicles make up only about 10% of all vehicles on the road, yet they generate more than 25% of global warming emissions. The burning of fossil fuels like gasoline and diesel releases carbon dioxide, a greenhouse gas, into the atmosphere. Electric vehicles, fuel-efficient cars, and clean fuels are some of the solutions being implemented to reduce emissions from the transport sector.

Electric vehicles produce fewer emissions than conventional vehicles

Transportation is a major source of air pollution and the largest source of heat-trapping emissions in the United States. Cars, trucks, and buses powered by fossil fuels are the biggest culprits. In 2020, transportation accounted for 27% of greenhouse gas emissions in the US, with passenger cars and light-duty trucks responsible for 57% of these emissions. The burning of fossil fuels like gasoline and diesel releases carbon dioxide, a greenhouse gas, into the atmosphere, causing the Earth's atmosphere to warm and leading to changes in the climate.

Electric vehicles (EVs) produce fewer emissions than conventional vehicles. While it is true that the production and use of all vehicles and fuels have environmental costs, and that manufacturing an EV emits more CO2 than manufacturing a comparable gasoline-powered vehicle, this increase is more than offset by lower emissions from fuel consumption by EVs. In fact, it takes between one and two years of typical driving for an EV to pay back its higher initial emissions. Furthermore, EVs produce zero direct emissions, and zero tailpipe emissions when running only on electricity.

A 2020 study over 59 different regions found that driving an electric car is better for the environment than driving a gasoline-powered car in 95% of the world. EVs will also play an important role in achieving the net-zero greenhouse gas emissions target set for 2050. However, it is important to note that the emissions associated with EV manufacturing are expected to decrease in the future by moving parts of the production to countries with cleaner power grids, such as the United States.

While battery recycling is currently difficult, researchers are developing new technologies to make it easier. Improving recycling would not only reduce the cost of batteries but also the emissions associated with making and disposing of them. Additionally, as more and more renewable energy sources are added to the grid, the carbon footprint of EVs will continue to decrease over time.

Transport is the fastest-growing contributor to climate emissions

Transport is the largest contributor to US greenhouse gas (GHG) emissions, accounting for about 28% of the total in 2022. This figure is even higher in some individual US states, with the transport sector responsible for 41% of California's GHG emissions in 2016. Between 1990 and 2022, GHG emissions in the transportation sector increased more in absolute terms than in any other sector.

Transport emissions, which include road, rail, air, and marine transport, accounted for over 24% of global CO2 emissions in 2016. They are expected to grow at a faster rate than emissions from any other sector, posing a significant challenge to global efforts to reduce emissions in line with the Paris Agreement and other international goals.

The primary sources of transport emissions are cars, trucks, commercial aircraft, and railroads, with tailpipe emissions from cars, trucks, and buses accounting for over one-fifth of the United States' total global warming pollution. Heavy-duty vehicles make up only about 10% of all vehicles on the road, yet they generate more than 25% of global warming emissions from the transport sector. Communities adjacent to ports and interstates bear the brunt of exposure to this dangerous air pollution.

To address the issue of growing transport emissions, the EPA and DOT have issued joint rule-making that sets GHG emissions and fuel economy standards for cars, light trucks, and heavy-duty trucks. The EPA has also implemented the SmartWay program, which helps the freight transportation sector improve supply chain efficiency, reduce greenhouse gases, and save fuel costs for participating companies. In addition, the EPA provides online resources such as the Green Vehicle Guide to help consumers choose more fuel-efficient vehicles.

Transport emissions cause illness and death

The transport sector is responsible for a large proportion of air pollution, as well as being a leading source of greenhouse gas (GHG) emissions. In 2020, transportation accounted for 27% of US greenhouse gas emissions, with passenger cars and light-duty trucks responsible for 57% of that figure. In the same year, motor vehicles produced about 22% of total US GHG emissions.

Transportation is a significant contributor to particulate air pollution exposure, which is most closely linked to air pollution-related deaths and illnesses. An estimated 4.2 million premature deaths are attributed to outdoor air pollution. Higher air pollution concentrations increase the risk of cardiovascular and respiratory diseases, cancer, adverse birth outcomes, and higher death rates.

Pollutants from vehicle exhausts can affect more than just the lungs. Studies have linked them to adverse impacts on nearly every organ system in the body. Exposure to pollution is inequitable, with Latinos, Blacks, and lower-income households disproportionately affected.

Road traffic injuries are one of the top ten causes of death worldwide, resulting in about 1.35 million deaths annually. Between 20 and 50 million people sustain non-fatal injuries each year, with long-term adverse health consequences.

A study of more than 57,000 women found that living near major roadways may increase a woman's risk of breast cancer. Another study found that exposure to emissions was linked to adverse effects on gestational duration and possibly intrauterine growth.

Strategies to reduce vehicle miles travelled can reduce emissions

Strategies to reduce vehicle miles travelled can indeed reduce emissions. Transportation is a major source of air pollution, particularly in the United States, where it is the largest contributor to heat-trapping emissions. Motor vehicles emit pollutants, predominantly carbon dioxide, that contribute to global warming and climate change. Passenger cars and light-duty trucks account for a significant proportion of these emissions.

One strategy to reduce vehicle miles travelled is to encourage active transportation, such as biking and walking, for short to medium distances. This not only reduces emissions but also promotes a healthier lifestyle. For longer distances, public transportation, such as trains, is a more efficient option than cars, reducing emissions by up to 80%. Carpooling and car-sharing are also effective ways to reduce the number of vehicles on the road and, consequently, their emissions.

Another strategy is to implement pricing policies and travel demand management programs. For example, the California Global Warming Solutions Act aims to reduce greenhouse gas emissions in the state by 40% below 1990 levels by 2030. This includes a target to achieve a 15% reduction in travel by light-duty vehicles by 2050. Additionally, the EPA's SmartWay program works with the freight transportation sector to improve supply chain efficiency, reduce greenhouse gases, and save fuel costs.

Transitioning to electric vehicles (EVs) is also a crucial strategy to reduce emissions. Electric vehicles produce fewer emissions than conventional petrol or diesel cars, especially when powered by renewable energy sources. A growing number of cities are committing to 100% zero-emission transit buses, and electric trucks are becoming more prevalent. However, it is important to note that the manufacturing and charging of electric vehicles can still contribute to emissions, and the transition to a fully electric fleet may not happen at the required pace without the right policies and investments from governments.

Finally, improving fuel efficiency and vehicle technology can help reduce emissions. This includes increasing fuel economy, reducing idle time, and adopting cleaner, low-carbon fuels. These strategies not only reduce emissions but also save money for consumers and reduce dependence on foreign oil.

Heavy-duty vehicles generate more than 25% of global warming emissions

Transportation is a major source of air pollution, with the transportation sector being the largest contributor to US greenhouse gas emissions. In 2020, transportation accounted for 27% to 28% of greenhouse gas emissions in the US, with passenger cars and light-duty trucks being the largest contributors, followed by medium and heavy-duty trucks.

Heavy-duty vehicles make up only about 10% of all vehicles on the road, yet they generate more than 25% of global warming emissions, 45% of NOx emissions, and nearly 60% of direct PM2.5 emissions from on-road vehicles. As the US moves more and more freight each year, the challenge of reducing emissions from this sector will continue to grow.

The US Environmental Protection Agency (EPA) has been taking steps to reduce GHG emissions from the transportation sector. One example is the SmartWay program, which helps the freight transportation sector improve supply chain efficiency, reduce greenhouse gases, and save fuel costs for companies that participate. The EPA has also set GHG emissions and fuel economy standards for cars, light trucks, and heavy-duty trucks.

To further reduce emissions from heavy-duty vehicles, diesel fleets can be switched to electric-powered fleets, which would significantly reduce toxic tailpipe emissions. Electric vehicles produce fewer emissions than conventional vehicles, and a growing number of cities are committed to having 100% zero-emission transit buses in their fleets.

Frequently asked questions