Electric vs. gas cars: Which is better for the environment?

Electric vehicles (EVs) promise a cleaner transportation future – but just how true is that vision? Let's take a look at a few European studies comparing EVs to conventional internal combustion engine (ICE) cars and let the data speak for itself.

The evidence is clear: from "cradle to grave," electric cars have lower overall emissions in just about every scenario than their gas-powered counterparts. At the end of 2020, engineering and environmental consultancy firm Ricardo, alongside specialists in the European energy and environmental sector, delivered a conclusive report analyzing the lifecycle emissions of road vehicles. The result? "Our assessment has shown that over their entire life-cycle in the EU, new electric vehicles are expected to have significantly lower impacts on the climate compared to conventional combustion engine vehicles," said Nikolas Hill, a project manager at Ricardo.

This figure summarizes the key takeaway from the whole report:

The chart above shows the Global Warming Potential (GWP) of battery electric vehicles (BEV) as compared to the GWP of traditional cars in 28 different countries. The furthest column to the left is the GWP for internal combustion engines, the second bar from the left is the GWP for diesel cars, and the third bar from the left is the total pan-European GWP for all battery electric cars. Most notably, in every country except for Estonia, BEVs have a lower (and oftentimes significantly lower) GWP.

Why do emissions differ by region?

Electric cars get their fuel from the electrical grid. Fun fact about the grid – depending on where you are in the world, the electricity flowing through the wires around you was generated from a wide range of sources, both fossil fuel-based and renewable. For example, in Poland, much of the country's electricity generation still comes from coal, while in Germany, wind and solar make up a larger share. This means that using electricity from the grid (like when you charge an electric car) can mean a different carbon impact depending on where you are. This is known as carbon intensity, and it is a useful way to compare the electricity mix of different regions and countries. The chart below shows different carbon intensities by country for 2020, as well as projected carbon intensities for 2050:

Carbon intensity values for European countries

Estonia has a carbon intensity of 1.02 tonnes of carbon dioxide per megawatt-hour (MWh), making it the highest value in the figure. High carbon intensity means more carbon dioxide per electric vehicle charge, which is why Estonia has such a high GWP.

Where does the U.S. fit into all of this? According to emissionsindex.org, our carbon intensity was somewhere around 898 pounds of carbon dioxide per MWh as of Q3 2020, which translates to roughly 0.41 tonnes/MWh – in the ballpark of countries like Romania, Greece, and Ireland. And in Romania, for example, BEVs have a 50 percent lower GWP than conventional vehicles, indicating that electric cars are well-suited to producing lower overall emissions in the U.S. as well.

A lifecycle analysis, or an LCA, is the backbone of this study. Simply put, a lifecycle analysis takes into consideration all stages of a product, from production to use to disposal and end-of-life. For this study, Ricardo referenced several factors in their LCA, including vehicle production (extraction of raw materials, processing, assembly, painting, etc.), vehicle use (driving, charging, maintenance, etc.), and end-of-life (re-use, recycling, disposal to landfills, etc.):

Lifecycle analyses are important for these types of studies, as it can be easy to underestimate the full scope of impacts a car can have throughout its existence. If you only considered a car's lifecycle to include the period of time when it is actively driven and used, you'd come up with a much different environmental impact estimate. Production and end-of-life processes for the products we use every day are surprisingly robust, and the environmental impacts from those stages can't be ignored.

While the Ricardo study is certainly one of the more robust and comprehensive LCA studies on EVs, they're not alone in their conclusions that EVs are better for the environment. Here are a few more studies that support their claims:

BNEF Electric Vehicle Outlook, 2020

BloombergNEF is Bloomberg's primary research arm covering transportation, clean energy, and more. In the 2020 version of their annual Electric Vehicle Outlook, they estimate that the total carbon dioxide emissions from battery electric vehicles are far below the emissions from traditional combustion engine vehicles in five major countries:

According to the report, lifecycle carbon dioxide emissions of electric cars produced in 2020 and then driven for 250,000 kilometers are between 18 percent and 87 percent lower than internal combustion vehicles.

Transport & Environment LCA report

Transport & Environment is a leading clean transport advocacy and campaign group in Europe. They release annual reports on electric vehicles and clean transportation, as well as conduct research and advocate for new energy and transportation policies. Their findings mirror the previous two studies: in all countries studied, electric vehicles emitted less carbon dioxide than their gas-powered counterparts:

Want even more interesting emissions comparisons between electric cars and gas-powered options? A recent project out of the Trancik Lab at MIT called Carbon Counter lets you compare your exact car model to the rest of the auto landscape with an interactive graph – you can even customize the data for your specific state! It also charts cars on a cost of ownership axis for another dimension of comparison. Unsurprisingly, their tool shows that EVs contribute far lower volumes of greenhouse gasses to the atmosphere, in line with all of the studies we mentioned above.

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