Image provided by CHUTTERSNAP via Unsplash. 

TL;DR: Electric vehicles reduce many harmful tailpipe emissions and can improve urban air quality, but they still generate pollution through non-exhaust wear, electricity generation, and battery production. Despite these challenges, EV adoption paired with renewable energy and other sustainable solutions offers public health and environmental benefits.

Electric vehicles (EVs) have been touted as an eco-friendly alternative to gasoline-powered cars. Yet, with EV battery manufacturing and charging emissions, are electric vehicles truly as eco-friendly and pollution-free as they initially seem?

On the road emissions

Cars have different kinds of emissions. The most recognized car emissions come from using the vehicle to drive. However, there are even different types of emissions that can come from driving: exhaust air pollution and non-exhaust air pollution.

Exhaust air pollution 

Exhaust air pollution refers to tailpipe emissions. This type of air pollution comes from burning gasoline to produce energy in cars with diesel or gas engines. Tailpipe emissions produce carbon dioxide, particulate matter (PM), carbon monoxide (CO), and nitrogen oxides (NOx). Diesel exhaust emissions additionally include volatile organic compounds, polycyclic aromatic hydrocarbons, benzene, formaldehyde, and acetaldehyde.

Clarity Movement’s flagship Node-S air quality sensor monitors particulate matter (PM2.5) and nitrogen dioxide (NO2). 

Exhaust air pollution can have serious consequences. Nitrogen oxides (NOx) react in the atmosphere, creating ozone (O3) and smog, which lingers over urban spaces. Fine particulate matter enters deep into the body, resulting in adverse health consequences. Fortunately, since electric vehicles do not burn gasoline, they produce none of these harmful air pollutants. 

Non-exhaust air pollution 

Driving a car produces a lot of friction between the tires, the brakes, the clutches, and the road. This kind of friction results in wear and tear, producing particulate matter air pollution. This emission source is significant, especially considering how exhaust air pollution has been decreasing due to greater engine restrictions, whereas non-exhaust air pollution in cars is less regulated. 

This graphic shows the fine particulate matter (PM2.5) emissions from different kinds of vehicles, taking into account how much PM2.5 comes from the car’s exhaust, and how much does not. 

Many factors determine how much non-exhaust air pollution a car produces, including the material composition of brakes, roads, and tires, as well as the weight of the vehicle. How the driver maneuvers the road can make a big difference, too. Aggressive driving with lots of sharp accelerations, brakes, and turns can create more air pollution. Thus, the amount of non-exhaust air pollution produced can vary widely between different EVs and different diesel and gasoline cars. 

Electric vehicles tend to emit less particulate matter from braking because they use regenerative braking. Regenerative braking converts the energy from the moving car into electricity, which can be used to recharge the EV’s battery. It is more efficient than regular car braking and results in less wear and tear on the brakes. 

However, electric vehicles tend to be heavier than conventional cars because of the weight of the car battery. This results in greater tire wear and road dust suspension. Therefore, even with regenerative braking, EVs are not significantly better than other vehicles when it comes to non-exhaust air pollution. Improvements in EV technology could make future electric vehicles lighter than they are now, addressing this issue.

Emissions from charging 

Not all car-related air pollution emissions come from on-the-road driving. For electric vehicles, emissions come from generating the electricity needed to charge the vehicle. The amount of air pollution that this produces varies based on how local power is generated. Renewable energy sources such as wind and solar will produce little to no air pollution, whereas power plants that rely on fossil fuels and unclean energy sources, such as coal, will produce far more air pollution. 

The United States EPA has a resource that allows you to find out the electricity production in your area by typing in your zip code. This EPA graphic shows the fuel mix for different regions across the country. A Subregion map can be found here.

Even after taking into account emissions from charging, electric vehicles typically produce lower levels of greenhouse gases than an average new gasoline car. Also, by shifting the air pollution emissions to power plants, the pollutants are being taken out of high-population urban hotspots, where they can hurt fewer people. Studies in Taiwan, Barcelona, and Madrid all show overall air pollution improvements from EV adoption, while accounting for charging emissions.

Emissions from the car’s creation

Electric vehicles have a different process than other kinds of cars. In particular, EV batteries undergo an intense production process that requires a significant amount of electricity. As previously mentioned, this electricity can come from unclean energy sources that produce air pollution. Manufacturing battery cars produces roughly 60% more carbon emissions than their fossil fuel counterparts. 

Even with these increased emissions, EVs still tend to produce less carbon emissions than other vehicles throughout their whole life cycle, from manufacture to scrapping. The initial “carbon debt” produced through battery manufacturing usually gets paid off after several years of driving. The time frame this occurs depends on how clean the energy used for charging is. 

This graphic shows the CO2 emissions for different cars in the European Union, as well as how emissions compare between different countries in the EU. 

EV batteries also require metals that are often mined through problematic mining practices, which need to be addressed. This issue can be alleviated slightly through battery recycling, a process that also reduces an EV’s carbon footprint and air pollution emissions.

Results

Although EVs still produce air pollution, they usually do not produce as much as other kinds of vehicles. Additionally, the air pollution EVs produce is typically emitted far from urban centers. This makes them a net positive for cities suffering from unhealthy air. 

In fact, adopting more electric vehicles can have significant impacts on public health. A USC study showed that as ZEV (zero emission vehicle) adoption in California increased in a given zip code, local air quality improved, and asthma-related emergency room visits decreased. Between 2013 to 2019, for every additional 20 ZEVs per 1,000 people, there was a 3.2% drop in the rate of asthma-related emergency room visits. 

A UC Berkeley report claimed that 100% electric car and truck sales by 2035 would prevent as many as 150,000 premature deaths in the United States by 2050. This equates to nearly $1.3 trillion in health and environmental savings through 2050 as well. 

However, electric vehicles alone cannot solve the problem of air pollution. They are not carbon neutral and still produce air pollution. While EVs can be a smart investment, we should explore other green solutions as well, from public transportation to biking infrastructure. It is especially important to invest in more renewable energy, which can drastically reduce the emissions from electric vehicles and create a more sustainable future for all. 

Solar power is a valuable clean energy source. This image is provided by Soren H via Unsplash.

Looking forward

The best way to understand and protect against air pollution is to monitor it. Finding clean air solutions would not be possible without the right data. Partner with Clarity to establish a monitoring network that helps safeguard public health and the environment.