All technologies have environmental impacts, and even “zero-emission” vehicles do create carbon emissions, both in their manufacture and in generating the electricity used to power them.
Above: An electric vehicle charging curbside. Photo: Andrew Roberts / Unsplash
It’s reasonable to ask how much these emissions amount to, and how they could be reduced. Unfortunately, however, intelligent debate on the issue has been drowned out by the screams of the anti-EV crowd, which produces a never-ending stream of articles and posts with titles like “EVs’ Dirty Little Secret,” or “Are electric vehicles really clean?”
As we’ve discussed at length in this space, these writings invariably indulge in all kinds of exaggeration, logical fallacies and outright falsehoods in order to support the demonstrably incorrect idea that EVs pollute just as much as gas vehicles (and the even more preposterous idea that science and “the media” have been ignoring the issue of EV emissions for the last two decades).
Amid the flood of misinformation, the Union of Concerned Scientists has been an authoritative and reliable source of accurate information. The organization has published a series of detailed studies of the Long Tailpipe issue, regularly updated with the latest data. The first UCS study we cited, from 2012, confirmed that “even when charging an EV with electricity made only from coal, the dirtiest electricity source, the EV has better emissions than the average new compact gasoline vehicle.” Follow-up UCS studies in 2015 and 2017 reached similar conclusions (as have numerous studies from other organizations).
In a new article, “What Are the Benefits of Switching from Gasoline-Powered Cars and Trucks to Electric?” the UCS brings the emissions issue up to date.
“Since the goal is to reduce emissions, a natural question is: what are the net benefits of switching from gasoline-powered cars and trucks to fully-electric vehicles?” Writes David Reichmuth, a Senior Engineer in UCS’s Clean Transportation Program. “To answer that question, I and my colleagues in the Clean Transportation Program have analyzed the global warming emissions from all of the steps required to make and recharge EVs and compared that to the emissions from making and driving a comparable gasoline vehicle.”
In the first section, Reichmuth lists the emissions factors involved in generating the electricity to power an EV: raw-material extraction (e.g. coal and natural gas); delivering fuels to power plants; burning fuels to generate electricity; electricity distribution losses; and the efficiency of the vehicle.
He goes on to list the emissions factors involved in fueling an ICE vehicle (as so many of the anti-EV screeds do not): oil extraction; transport of crude oil; refining; delivery of fuel to gas stations; and combustion of fuel.
“Because of differences in electricity generation across the United States, the emissions produced from driving the average EV vary depending on where the vehicle is driven but everywhere in the United States, driving the average EV results in lower emissions than the average new gasoline vehicle,” Reichmuth writes. (This was already true in 2012, when 45% of US electricity came from coal, and it’s even more so now that the proportion of coal has dropped to 22%.)
Another way of looking at the equation: How efficient would a gasoline vehicle need to be to have the same global warming emissions as an EV? “More than 90 percent of US drivers live in regions where driving an EV is like getting 59 miles per gallon in a typical car. Based on where EVs have been sold in the United States, driving on electricity produces emissions equal to those of a gasoline car getting 91 miles per gallon.” (Needless to say, no gas car gets anything like that—the average hybrid gets around 51 mpg.)
The UCS report brings up an important point that many car buyers overlook: as is the case with gas vehicles, efficiency matters. “The more efficient the EV, the greater the benefits of switching from gasoline to electricity.” For example, the emissions from driving a 2021 Tesla Model 3 Standard Range Plus in California equal those of a gasoline car getting 152 miles per gallon. “The Tesla’s global warming emissions are a fifth of those of the average new gasoline car and over 60 percent less than even the most efficient gasoline car on the market,” says UCS.
The efficiency question is becoming even more relevant as large SUVs and pickup trucks start to go electric. “Larger vehicles, whether gasoline or electric-powered, are less efficient,” UCS points out. “However, everywhere in the United States, the emissions from driving an EV pickup truck are lower than those for the average new gasoline or diesel pickup truck.”
To explore the relative emissions of various EV models in different regions of the country, try UCS’s EV emission tool, or check out Carbon Counter. Also see fueleconomy.gov, which shows the efficiency and MPGe (miles per gallon equivalent) figures for most models on the US market.
Emissions from energy usage are only half the story, and UCS doesn’t gloss over the facts: “Manufacturing an EV results in more global warming emissions than manufacturing a comparable gasoline vehicle. This is chiefly due to the energy and materials required to produce an EV’s battery.”
Most of the “Let’s stick with gas” posters will stop right there, and leave their Facebook readers to draw their own ovine conclusions. However, most of the emissions over the lifespan of today’s vehicles occur during use, so the reductions from driving an EV more than offset the higher manufacturing emissions.
A useful way to look at this is to consider the “breakeven point.” How far does a particular EV need to drive for its lower usage emissions to cancel out its higher manufacturing emissions (or to get rid of its “climate backpack,” as some put it)?
“This breakeven point varies depending on regional electricity emissions,” writes Mr. Reichmuth. “Based on where the US population lives, the mean breakeven point for an electric car with a 300-mile range compared with the average new gasoline sedan is 21,300 miles of driving, or 22 months based on average annual driving. Breakeven occurs more quickly, after about 17,500 miles (17 months), when comparing an electric truck with 300-mile range with the average new gasoline pickup truck.”
The latest UCS report bears out an important point that EV fans have long made: EVs get cleaner over time as the electric grid gets cleaner, whereas ICE vehicles do not (if anything, they get dirtier as they get older). If you compare this most recent UCS report to those from 2012, 2015 and 2017, you’ll see the green tint grow brighter and brighter.
Electric cars and trucks are much cleaner than their gasoline counterparts, but there’s still room for improvement. UCS points out that drivers need to choose the most efficient EV that meets their needs, and the industry needs to continue working to reduce the environmental footprint of raw material extraction, and to develop a circular supply chain based on recycling materials from used batteries. And to truly clean up our act, we need to make a speedy transition to renewable electricity alongside the transition to e-mobility.
Source: Union of Concerned Scientists