“It’s never too late to mend”: The United States Catastrophic Transportation System
Have you ever wondered how traveling from one place to another affects our climate?
The transportation sector is one of the largest contributors to anthropogenic U.S. greenhouse gas (GHG) emissions. According to the Inventory of U.S. Greenhouse Gas Emissions and Sinks 1990–2020 (the national inventory that the U.S. prepares annually under the United Nations Framework Convention on Climate Change), transportation accounted for the largest portion (27%) of total U.S. GHG emissions in 2020. Cars, trucks, commercial aircraft, and railroads, among other sources, all contribute to transportation end-use sector emissions.
Figure 1: 2020 U.S. GHG Emissions by Sector (Source: U.S. Environmental Protection Agency [EPA])
Figure 2: 2020 U.S. Transportation Sector GHG Emissions (Source: U.S. Environmental Protection Agency [EPA])
In 2020, U.S. greenhouse gas emissions totaled 5,222 million metric tons of carbon dioxide equivalents after accounting for sequestration from the land sector.
Emissions decreased from 2019 to 2020 by 11% (after accounting for sequestration from the land sector). The primary driver for the decrease was an 11% decrease in CO2 emissions from fossil fuel combustion. This decrease was primarily due to a 13% decrease in transportation emissions driven by decreased demand due to the ongoing COVID-19 pandemic. Electric power sector emissions also decreased 10%, reflecting both a slight decrease in demand from the COVID-19 pandemic and a continued shift from coal to less carbon intensive natural gas and renewables.
Greenhouse gas emissions in 2020 (after accounting for sequestration from the land sector) were 21% below 2005 levels.
Figure 3: One of the United States Street view (Source: https://www.epa.gov/transportation-air-pollution-and-climate-change/smog-soot-and-other-air-pollution-transportation)
EPA Policies to reduce GHS Emission-
U.S. Environmental Protection Agency (EPA) is addressing climate change by taking the following actions to reduce GHG emissions from the transportation sector. Many of these programs have benefits beyond cutting carbon. For example, decreasing fuel consumption can reduce our dependence on foreign oil and save consumers money at the pump.
- EPA and DOT issued a joint rule-making that set GHG emissions and fuel economy standards for the largest sources of greenhouse gases from transportation, including cars, light trucks, and heavy-duty trucks.
Light-duty GHG regulations for passenger vehicles and trucks are projected to:
i- Cut 6 billion metric tons of GHG emissions over the lifetimes of the vehicles sold in model years 2012-2025 and allowing manufacturers flexibility in meeting the standards.
ii- Nearly double the fuel efficiency while protecting consumer choice; and
iii- Reduce America’s dependence on oil and provide significant savings for consumers at the pump.
Heavy-duty GHG regulations are projected to:
i- Reduce CO2 emissions by about 270 million metric tons over the life of vehicles built under the program, saving about 530 million barrels of oil; and
ii- The proposed “Phase 2” program includes standards that would further reduce GHG emissions and improve the fuel efficiency of medium and heavy-duty trucks.
2. Congress created the Renewable Fuel Standard program in an effort to reduce greenhouse gas emissions and expand the nation’s renewable fuels sector while reducing reliance on imported oil. Renewable fuels are produced from plants, crops and other biomass, and can reduce greenhouse gas emissions when compared to burning the fossil fuels they replace.
3. EPA along with the Federal Aviation Agency at the United Nations’ International Civil Aviation Organization have developed international carbon dioxide emissions standards for aircraft. EPA is also now working through the process of potentially setting domestic regulations under the Clean Air Act that address GHG emissions from certain classes of engines used in aircraft.
4. The 2007 Energy Independence and Security Act requires federal agencies to only acquire cars, light trucks, or medium-duty passenger vehicles that are low greenhouse gas emitting. Each year, EPA evaluates the greenhouse gas emissions performance of the fleet to determine which vehicles in each class emit less harmful greenhouse gases. The law requires federal agencies to purchase these high performing vehicles. Over time this will result in a greener federal fleet.
5. SmartWay helps the freight transportation sector improve supply chain efficiency, reducing greenhouse gases and saving fuel costs for companies who participate. Through SmartWay, EPA and its partners are making significant gains in the efficiency of how our nation moves goods, helping address air quality challenges, improving public health and reducing freight’s contribution to climate change.
6. Since the mid-1970s EPA has required automakers to display a label on new cars and light trucks with information on vehicles’ fuel economy and fuel costs. Labels on today’s cars also include ratings on greenhouse gas and smog-forming pollutants. EPA provides online resources, such as the Green Vehicle Guide and the joint EPA-DOE website fueleconomy.gov, to help consumers identify vehicles that can save them money at the pump and reduce their transportation-related emissions. EPA’s SmartWay light duty program goes further and identifies the top performing vehicles in terms of fuel economy and emissions to assist consumers in making an environmentally friendly purchase.
7. State and Local Transportation Resources Center for information on emission reduction strategies, national policies and regulations, incentive-based and voluntary programs, funding sources, calculators, transportation conformity, and other types of assistance to help states and local areas achieve their air quality and transportation objectives.