Adding fossil carbon to the atmosphere seems like a pretty important one though.

The pandemic proved that pollution is primarily caused by trucks and not cars. Most of the highest polluted cities in the world that were clear during the global lockdown regained their pollution once trucks went back on the road.

Genuine question: How do you know this? (Maybe a source or something)?

I know the supply chain got messed up, but given that trucks are so crucial to transporting goods (at least here in the US) I would think that trucks remained on the road during the pandemic while individuals driving cars all stayed home during quarantine.

I'm really curious how this conclusion ('trucks are the primary cause of pollution') was reached

Probably something like this:

> In the most recent year for which data are available, combination trucks made up only 1% of the vehicle population but were responsible for 6% of all vehicle miles traveled (VMT) and 17% of vehicle fuel use.

Given that diesel is often considered "more polluting" you can probably make it work out given a bunch of assumptions that may or may not apply. Trucks are the primary cause of road wear, for example.

Trucks also produce the lions' share of the noise pollution. Don't laugh, noise pollution is very serious; it causes cognitive damage to people who live near busy roads which in turn has innumerable deleterious social effects.

There’s a number of climate fights that I think would be better argued with noise pollution reduction instead of carbon reduction, and vehicles especially trucks is one of them.

> Given that diesel is often considered "more polluting"

Modern diesel engines are less polluting than unleaded cars, thanks to diesel particle filters:

"gasoline cars emitted on average 10 times more carbonaceous PM at 22°C and 62 times more at -7°C compared to diesel cars"

[1] https://phys.org/news/2017-07-diesel-gas.html