One of the major reasons why EVs are becoming more popular is the desire to reduce one's own carbon footprint. At the same time, eye-popping lease deals on EVs have sprouted up, in part because of the lease loophole for the $7500 tax credit, where dealerships are able to pass on that savings for some vehicles via leases only, rather than through outright purchases. Leasing an EV also can have the upside of allowing the lessee to upgrade their vehicle to newer technology within 2-3 years, which can be important given the rate with which EV battery life, reliability, and range has been improving.
However, a part of the picture that has not been talked about enough is the potential carbon footprint impact of having many leased EVs out there, as opposed to many EVs which are bought and then held by a single owner for a long time. In this 2021 article from Reuters, and in this 2023 article on factcheck.org, the "break-even" point in terms of how many miles an EV must be driven before breaking even in terms of carbon emissions, is discussed at length. From both sources, that break-even point varies wildly depending on the source of the electricity used, as well as the type of vehicle, but averages out to be somewhere between 15,000-20,000 miles. Discussion of the break-even point is necessary because EVs often require a greater carbon footprint than ICE vehicles up front to manufacture, which then is offset within the first few years of driving.
A typical starter EV lease deal is for 10,000 miles maximum of driving, for 2 or 3 years. Thus, at the end of the initial lease, that vehicle, depending on the type of electicity that the lessee uses, is probably either right near the break-even point, or slightly past it. The true gains for the EV outpacing a comparable internal-combustion engine vehicle come after that initial lease period has expired.
By purchasing an EV outright, the initial owner can guarantee that, with an efficient source of electricity used to charge it, that that purchase sees it through to 100,000+ miles, to lock in years and years of reduced carbon footprint. However, by leasing the EV, and by giving it up after only 20,000 miles, the original owner cedes control over whether that vehicle will ultimately end up realizing its true reduction in carbon footprint. The total carbon footprint of these leased EVs, which are subsequently returned at the end of the lease period, depends entirely on the rate with which dealerships are able to re-sell, or re-lease, the vehicle when the initial lease term is up.
Of course, lessees who end up purchasing the vehicle outright at the end of the lease period also continue to have control of seeing that vehicle through to 100,000+ miles of usage, just like those who buy the vehicle upfront.
End-of-lease EVs are expected to increase in supply in the coming years, and the thing to watch will be, are a high percentage of these vehicles eventually re-sold and driven for a long time, or do a sizable percentage of them not ever even reach 75,000+ miles. Vehicles which are not used to their full potential lifespan would not be a good thing, in aggregate, for the environment. The extent to which potential used EV buyers trust that these vehicles can continue to be reliable, and will not have premature expensive battery/electrical repairs, will undoubtedly be crucial in ensuring that this scenario does not come to pass.