How much CO2 does a car emit per year?

The EPA puts a typical passenger vehicle at about 4.6 metric tons of CO2 a year, driving roughly 11,500 miles at 22 mpg. Offsetting that with trees would take about 219 of them absorbing carbon for a full year.

How much CO2 does an eBike produce?

About 6 grams per mile, almost all of it from the electricity used to charge the battery, against roughly 356 grams for a petrol car and 92 for a battery electric car. An eBike is not zero, but it is close to two orders of magnitude below driving.

Does replacing car trips with an eBike actually make a difference?

Per mile shifted, yes — the gap between 356 and 6 grams is large enough that even a partial switch shows up. Short trips matter most: a cold engine is at its least efficient in the first few miles, which is exactly the distance an eBike replaces easily.

The Environmental Impact of Driving vs an eBike — CO2, Trees & Emissions

219 trees

absorbing carbon all year long, just to cancel out what one car emits in that same year. The EPA puts a typical passenger vehicle at 4.6 metric tons of CO2 annually — around 11,500 miles at 22 mpg — and a mature tree at roughly 21 kg a year. One car, a small wood.

CO2 per mile, by what you're riding in

Grams of CO2 per mile travelled, including the electricity to charge

Source: EPA. Electric figures include grid emissions at the US average mix.

59× is a big enough gap to survive the caveats

A petrol car puts out about 356 grams of CO2 for every mile it travels. An eBike, counting the electricity to charge it, is around 6. Even a battery electric car — genuinely a large improvement — sits at 92, still 15 times the eBike.

Arguments about grid mix, battery chemistry and manufacturing move these numbers around at the edges. None of them move a 59-fold gap. That is the useful thing about this comparison: you do not have to win the fine print for the conclusion to hold.

6 g

per eBike mile, charging included

356 g

per petrol car mile

1,800 MPGe

eBike energy equivalent

Short trips are where the damage is concentrated

A cold engine is at its worst in the first few miles. The catalytic converter has not reached operating temperature, the fuel mixture is rich, and per-mile emissions on a two-mile errand run well above the sticker figure the car is rated at. Those are exactly the trips an eBike takes over most easily — the school run, the shop, the station.

Which is why replacing a fraction of your driving does more than the fraction suggests. You are not removing average miles; you are removing the dirtiest ones.

What these numbers leave out

Everything here is tailpipe-and-charging: the carbon of using the vehicle, not of building it. Manufacturing an eBike has a real footprint, mostly in the battery — but so does manufacturing a car, at a scale a couple of orders of magnitude larger. Counting production on both sides widens the gap rather than narrowing it.

The electricity figure also assumes the US average grid. Charge on a cleaner grid and the eBike number falls further; charge on a dirtier one and it rises a little. It is a small term either way — an eBike uses about as much electricity over a year as a fridge does in a month.

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