14 Comments

Love the last point. America needs more bus lanes, bike lanes, and rail lines. Not just in the city, but inter-city high-speed rail would be a massive reduction in emissions and also reduce travel times for a lot of trips.

Electric vehicles are only an incremental benefit over ICE vehicles. The real improvement is in building walkable cities.

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Hello Hannah, thank you very much for your great substack, and this article in particular!

I have a comment regarding the comparison of emissions (tailpipe) between electric and combustion cars.

For the electric cars, you did not only look at local tailpipe emissions of the cars, but also at the non-local emissions of energy generation. That's something I see often when the environmental impact of electric cars is discussed. You conclude that the energy mix of electricity generation matters (obviously). Then, you add that even with electricity generation entirely based on fossil sources, the health impact of electric care for the population may be lower due to shifting the emissions from densely populated areas to less populated areas.

However, in this comparison an important element is missing: the much higher energy efficiency of electric cars. A combustion engine car converts about 75% of the energy from the fuel into heat, which is wasted. Only 25% of the energy is turned into motion. An electric vehicle turns most of the energy it uses into motion, transmission losses for electricity are fairly low, and a modern power plant running on fossil fuels turns much more than just 25% of its fuel into electricity.

So overall, even with a grid run entirely on fossil fuels, the total exhaust emissions generated by an electric car would be much lower than those by a comparable combustion engine car.

Next, I wonder about the non-local emissions of combustion engine cars: do the studies you mentioned also look at the emissions generated in oil production, transport to the refinery, emissions generated at the refinery, and the emissions for transporting fuel to the gas stations? It seems to me that this additional "backpack" of non-local emissions generated by the fuel of combustion engine cars is often neglected - while at the same time, electricity generation emissions for electric cars are usually included in the discussion. Seems like an unfair comparison ...

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Could you please explain why in the graphic of non-exhaust emissions of PM 2.5 EV have 0,014 g/km and on the next graphic only 0,011 g/km ?? Should be the same in both graphics, right?

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I think we also need to take into account the emissions during the intensive mining process to acquire the very large amount of precious metals needed in the car battery. There are also geopolitical consequences to this “green” transition, as we rely more and more on the mining and raw material industry in china. It also raises ethical issues as there is ample evidence of china using the Uyghur population as slave labor. This is true especially with solar panels, because china has a near total monopoly on the manufacturing process of poly silicon

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Complaints are inherent to heavy vehicles, not electric vehicles. ebikes are also evs. Over half the evs in the world have just two wheels. Europeans are getting into little electric cars. Big heavy SUVs are an American/Canadian/Australian thing, and nothing could be more voluntary - the expense, the traffic accidents, the pollution, they're all prices for a lifestyle choice.

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Electric vehicles reduce not only petrol combustion, but also petrol transport, petrol production and petrol mining. This is overlooked when you concentrate on roadside emissions and electricity production.

And regenerative breaking makes EVs much more efficient. The Renault Zoe of our car sharing fleet runs on the equivalent of 1,5 litres gasoline per 100 km.

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Fascinating read, thanks for the research

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Interesting and somewhat surprising post - although I knew that there were non-exhaust emissions, I hadn't realised how big they were.

Another potential area of investigation: the impact of vehicle weight on road damage. I would agree that public transportation is the way forward, but according to the fourth power law (https://en.wikipedia.org/wiki/Fourth_power_law) a bus with a 5 tonne axle load would do 10,000 times the damage of a car with a 0.5 tonne axle load. If the axle load of the bus could be reduced to 4 tonnes, that would reduce the axle load 40% of the 5-tonne axle load bus.

So there's an argument for even marginal reductions in the weight of buses. In the case of electric buses, this could be an argument for investing in the overhead wiring required for trolleybuses to avoid the need to carry round the batteries required in battery electric buses.

Caveats:

(1) It sounds like there are some limitations in the evidence for the 4th power law.

(2) I have a bit of a thing about trolleybuses, going back some years to the debate around the introduction of trams in Edinburgh: http://www.scottishelectrictransit.org.uk/

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What will be thé hydrogen issues, today's lot of Hydrogen generation is màde out of coal and absolutely not "green direction" products, have a look to the following up to date chart, simply, look who. Where and how thit is produced..

https://www.spglobal.com/commodityinsights/PlattsContent/_assets/_files/en/specialreports/energy-transition/platts-hydrogen-price-wall/index.html?utm_source=insight&utm_medium=plattsblog&utm_campaign=lef

This is so much details and price details. Think about the 1$ for 1kg so unreal for the time being especially if green hydrogen via renewable electrolysis...we are far away of the realities...

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There are some specific issues with tire dust. It's been found that 6PPD is toxic to Coho salmon. https://en.wikipedia.org/wiki/6PPD. However, there is a solution, which is increased street sweeping. Much easier than trying to remove PM2.5s from the atmosphere!

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The tailpipe studies... Were they measuring emissions from new cars, or using manufacturer figures, or did they measure actual cars in use? The stop/start nature of town driving visibly produces more pollution than steady state testing done for MOTs and published figures.

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Great research, thank you for tackling this question. I knew EVs eliminated exhaust emissions but I was not sure about the numbers for non-exhaust emissions.

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