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Comment by fancyfredbot | Hacker News Reader

The less you drive an EV the harder it is to offset the embodied carbon involved in manufacturing it. There will be a point where, if you don't drive much, an EV emits more carbon than a internal combustion engine car. If you drive a bit more, the EV is more efficient than an ICE but less efficient than a hybrid with a smaller battery. If you drive a bit more the EV will be more efficient than either. The article picks one usage level and uses this single data point to claim the hybrid is more efficient than the EV which is both interesting and misleading.

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Good points.

In the grand scheme of things, I don’t think the CO2 emissions associated with EVs matter at all. Is our goal for to cut emissions by 10%? No. It’s to cut emissions by 100%. To reach that goal, we need all vehicles to be pure BEVs (approximately.. some ICE on biofuels/e-fuel could work, but it’s not sustainable on a large scale), materials must be near 100% recycled, and whatever mining is done most be done with electric equipment. To get there, the hard requirement is that we need to mine a certain amount of battery materials and build a certain amount of EV infrastructure. Hybrids contribution to this is mainly that they have some batteries, so they drive battery development and material production. Plug-in hybrids help drive EV infrastructure to a small degree. But nothing is better than just going pure BEV. The small short term CO2 emission gains that might be had with hybrids could easily be outweighed by the long term increased emissions associated with delaying the progression to a 100% renewable 100% carbon neutral ecosystem. But I won’t fault anyone from buying hybrids. Pushing for a more aggressive transition needs to be a policy decision. If hybrid makes more sense than EV from economic or practical point for you then that’s what you should go for.

> Is our goal for to cut emissions by 10%? No. It’s to cut emissions by 100%.

I don't think most people would want to live in the world where you've cut emissions by 100%.

Even making a bicycle emits some amount of emissions. Making a PV panel emits GHG emissions. Having a pet emits GHG emissions.

As the parent says, the goal is to have NET 0 emissions. Certainly some emissions will still occur but they need to be small enough to be offset by CO2 removal. Because it is almost always much easier to prevent emissions rather than remove CO2, preventing 100% emission from cars and their production is likely to be best path to NET 0.

Cutting emissions by 100% and being net zero are two different things. Emitting a bunch of GHG and then buying carbon offsets is radically different from never actually emitting GHG. And the parent never says "net", it says cut emissions 100%. You're reading words that aren't there.

If you wanted to cut emissions 100%, you would stop making cars. You would stop making busses. You would stop building roads. You would stop building trains. You would ground every plane. You would stop every boat. You would no longer have AC, you would no longer have refrigerators.

why? if you have power from other than fossil fuels, that power can be used to do anything that you would use fossil fuels for.

Fossil fuels aren't 100% of GHG emissions. It's a large percentage, yes, but not 100%. So sure, you've cut 90% or whatever, but not 100%. You're still probably using virgin plastics somewhere, still making concrete, still making asphalt, still making steel, still need refrigerants, etc.

Isn't the real goal negative emissions? We're well past safe levels of CO2 in the atmosphere.

I have unresolved questions surrounding this concept. I agree with you that for the X number of years that you own the vehicle, the less you drive the harder it is to offset the manufacturing-related carbon emitted.

Once you are done with ownership, that vehicle is going to be owned by someone else, and probably at least one or two people after that. How do we account for that? Do we assume that all vehicles will be driven the same distance over their lifetime? Should we even bother to consider this factor? Does it matter if the distance driven is front-loaded or back-loaded (the original owner drives a lot or a little)? Are we overcomplicating things?

For a vehicle which has multiple owners it's easy - it's the average usage over all owners which will matter.

My first comment was about emissions over a fixed amount of time. You could instead assume all vehicles lasted for a fixed number of miles instead of a fixed amount of time. If you do that (and you assume the vehicle lasts say 100k miles) then I suspect the EV would always be the greenest over its life. However, since we know that both the age of a car as well as it's mileage influence how usable it is I think my main point still stands. There's a range of levels of greenness which will depend on how you use and maintain your car.

Buy a used EV with 50k miles on it, problem solved

Keep in mind the embodied carbon also goes down as the rest of the supply chain switches to low carbon or carbon free alternatives.

we need a different word.

EV is more efficient than ICE and hybrids, that seems clear. but the context is day to day driving, not "Total Carbon Footprint" (TCF?).

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