Emissions on the Road: Environmental Impact of Automobiles and the Benefits of Going Green

Vehicles significantly impact the environment. According to the United States Environmental Protection Agency (EPA), 29% of the total greenhouse gas emissions in the country in 2021 were from transportation activities. These emissions contribute to environmental degradation — specifically air pollution, climate change and global warming — and impact your health and finances.

The financial impacts may be direct or indirect, from your bills — including food, utilities, gas, health costs and insurance — to possible loss of income or home due to extreme weather events. As we face different challenges brought about by climate change, making more responsible choices is necessary, especially concerning vehicle usage.

Understanding how driving habits contribute to global warming, as well as the auto insurance perks of going green with environmentally-friendly vehicles, is a good start. Although more significant action from government and companies is needed, these individual actions could still make a big difference.

Greenhouse gas emissions, including carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) emissions, contribute to environmental degradation. In the U.S., transportation activities cause the most emissions at 29%. According to the EPA, a typical passenger vehicle emits 4.6 metric tons of CO2 annually.

Net emissions increased by 6% compared to the 2021 total, mainly due to increased economic activity after the slowdown at the height of the COVID-19 pandemic. Overall, total emissions from the transportation sector grew 19% from 1990 to 2021.

Carbon dioxide emissions from energy consumption fluctuate as consumption levels regularly change. Petroleum remains the highest contributor to CO2 emissions in the industry. Although much lower, emissions from natural gas showed a consistent increase throughout the years.

Source: Energy Information Administration

In 2021, the transportation industry had the highest greenhouse gas emissions in the country among all economic sectors, up 18.6% since 1990. Year-over-year, emissions increased as economic activity grew, dropping after the COVID-19 pandemic slowdown in 2020. The 2021 total is slightly lower than the 2016, 2017, 2018 and 2019 numbers but trends upward. Historically, greenhouse gas emissions in the transportation sector peaked in 2007 when it recorded 1,967.25 million metric tons of carbon dioxide equivalent.

Source: U.S. Environmental Protection Agency

In 2020, Texas recorded the highest energy-related CO2 emissions in the U.S., with 624 million metric tons, including 192.7 million metric tons from transportation. Vermont had the lowest total CO2 emissions, recording only 5.6 million metric tons, with transportation-related emissions accounting for 2.9 million metric tons.

The map below shows total CO2 emissions per state.

Source: Energy Information Administration

Vehicles are among the highest contributors of greenhouse gas emissions, but not all vehicles emit the same amount. Factors such as engine technology, fuel type, usage patterns and vehicle size all affect emissions. Among on-road vehicles, light-duty trucks have the highest greenhouse gas emissions in 2021 at 671.8 million metric tons of CO2 equivalent. They're followed by medium- and heavy-duty trucks (417.1 million metric tons), passenger cars (374.2 million metric tons), buses (25.7 million metric tons) and motorcycles (7.5 million metric tons).

These include light-duty vehicles, which have a maximum gross vehicle weight rating (GVWR) of <8,500 lbs., and medium-duty vehicles (8,501–10,000 lbs.). Generally, the EPA considers a vehicle a passenger car if it’s primarily used for transporting 12 people or less. In 2021, passenger cars recorded the third-highest greenhouse gas emissions among on-road vehicles at 374.2 million metric tons. Aside from vehicle type, emissions also vary per fuel type.

Here's a breakdown of light-duty vehicle emissions reported by the Bureau of Transportation Statistics (BTS).

Light-duty trucks refer to vehicles that carry passengers and cargo. These include sport utility vehicles (SUVs) and minivans. In 2021, light-duty trucks across the country produced 671.8 million metric tons of CO2 equivalent emissions. The EPA also reported that light-duty trucks traveled more than 1,492,200 million miles in the same year.

The table below shows the differences in estimated average emission rates between gasoline- and diesel-fueled light-duty trucks.

Total emissions of medium- and heavy-duty trucks in 2021 reached 417.1 million metric tons of CO2 equivalent, making them the second-largest contributor among on-road vehicles. During the same year, these vehicle types traveled 317,245 million miles. Falling under this category are single-unit trucks, combination trucks, tractor-trailers and box trucks used for freight transportation and some vehicles not typically used for freight movement, such as service and utility trucks.

The table below shows the differences in emission rates between gasoline- and diesel-fueled heavy-duty vehicles.

Buses were the fourth-highest contributor of greenhouse gas emissions. They totaled 25.7 million metric tons of CO2 equivalent or 1.3% of all emissions. Specifically, bus emissions include 25.1 million metric tons of CO2, 0.2 million metric tons of nitrous oxide and 0.4 million metric tons of various hydrofluorocarbons (HFC).

Motorcycles had the lowest greenhouse gas emissions among on-road vehicles. In 2021, motorcycles totaled 7.5 million metric tons of CO2 equivalent. Specific emission rates for typical motorcycles are as follows:

In 2022, the world recorded its sixth-warmest year since 1880, ten of which have occurred since 2010. During this period, the world has witnessed climate anomalies like rising seas, droughts and severe flooding. Temperature changes throughout the years can be attributed to global warming caused by greenhouse gas emissions. Although there are multiple sources of emissions, motor vehicles produce some of the highest emissions. In the U.S., the transportation industry has the highest impact among all energy sectors.

The devastating effects of car emissions aren't restricted to weather-related events. Climate change also has an indirect effect on the economy, health and personal finance. Home values may decrease, utility bills may increase, and even insurance costs may go up due to higher risk of property damage from extreme weather events.

Cars, including passenger vehicles, play a massive role in global warming. They're among the major sources of greenhouse gas emissions. This isn't exclusive to the U.S. The transportation sector contributes 16.2% of all greenhouse gas emissions globally. Of these, 11.9% are from on-road vehicles.

Although it may seem minuscule, an individual's efforts can significantly impact if more people participate. With more responsible car owners opting for more sustainable choices, such as choosing a fuel-efficient vehicle, reducing vehicle usage and practicing eco-friendly driving habits, car emissions may decrease, air quality may improve, dependence on fossil fuels may reduce and overall environmental sustainability may be enhanced. The United Nations further highlighted the need to take action as achieving sustainable transport is also part of the sustainable development goals under the Paris Agreement on Climate Change.

Here are a few steps car owners can take to reduce carbon footprints:

Auto insurance provides financial protection against unexpected incidents. But depending on the policy, this may come at a high price. Many auto insurance providers offer green or eco-friendly auto insurance, in which green efforts are rewarded with discounts. Green car insurance may also refer to programs that allow you to pay premiums based on how much you drive.

The principle behind green auto insurance is to promote sustainable driving practices by offering incentives to drivers who adopt environmentally responsible practices. Among common offers by green insurance providers is a specialized coverage option for low-emission vehicles like hybrid and electric cars. For instance, insurers may provide higher coverage limits for replacement parts and repairs than traditional policies. Carriers might also offer additional coverages, such as batteries and power cables, or create incentive programs to help green drivers save money on insurance.

For some insurance companies, green auto insurance comes from usage-based policies. With this, you'd only pay insurance for how much you drive. For example, the fewer miles you accumulate, the lower your premium. This is a way to reward drivers who reduce their car emissions and practice eco-friendly driving, such as smoother acceleration and braking and avoiding peak traffic hours.

Pay-as-you-drive programs generally work by installing a mileage-tracking device in the vehicle. Those enrolled in these programs usually get policy discounts if they drive fewer miles than average.

Incentivizing more environmentally-friendly transportation choices is a way to encourage more individuals to go green. Aside from pay-as-you-drive programs and specialized coverages, insurance providers that promote green auto insurance also offer other rewards.

Throughout the years, efforts to address climate change have expanded to various industries. In the transportation sector, the availability of more eco-friendly vehicles in the automotive market provides consumers with more sustainable alternatives. Eco-friendly vehicles run using alternative energy options or are more fuel efficient.

There are various benefits to an eco-friendly vehicle. Energy-efficient cars tend to have less greenhouse gas emissions. They may also help reduce expenses in the long run as you decrease fuel consumption. Here's what to consider if you're thinking about making the switch to an eco-friendly vehicle.

Choosing to go green is a huge decision that requires commitment. MoneyGeek asked a few industry experts to provide some insights to help you better understand the correlation between vehicles and climate change.

Being informed about how cars affect global warming and educating yourself about possible solutions can help you start your journey to driving green. MoneyGeek listed some resources you may find helpful.

• AAA Electric Vehicle Range Testing: Compare the driving range of different EVs in the country. Find out what factors affect their driving range.
• AirNow: Enter your ZIP code, city or state and get air quality data.
• Center for Climate and Energy Solutions: Get tips on reducing transportation emissions. Check out other ways to reduce your home and work carbon footprint.
• Fueleconomy.gov: Compare cars' EPA ratings and features and see which is best for your needs. Access driving and gas mileage tips to become a more efficient driver.
• Health Effects Institute: Read studies about air pollution, common sources and health effects of long-term exposure.
• Kelley Blue Book: Search for cars for sale near you. Read reviews and compare different car types, models and prices.
• NASA Global Climate Change: Learn more about climate change, its causes, effects, global warming and what can be done to solve the problem. Monitor global temperature changes and carbon dioxide levels.
• National Conference of State Legislatures: Check out state policies on hybrid and EVs. Learn which states offer incentives.
• U.S. Department of Energy: Find resources on energy and fuel efficiency.
• U.S. EPA's Green Vehicle Guide: Find out what SmartWay Certified vehicles are and how they can help reduce greenhouse gas emissions. Search for SmartWay vehicles based on model year, make and vehicle class.
• U.S. EPA's Vehicle Emissions Inspection and Maintenance: General information for motorists: Learn about vehicle inspection and maintenance programs. Access relevant state and local government websites.