I’m sure i’ve seen something on the TV about deep sea mining and it didn’t look like it was any good for the environment down there.
I think the summary is it’s pretty catastrophic for the ecology of the volcanic vents being mined. But that’s offset by the fact that you only need to mine comparatively small areas of a very big ocean. BUT, that in itself isn’t without it’s problems, these ecosystems are so specialized it’s possible they contain species that don’t exist even on other vents.
The solution isn’t more cars, it’s EV’s to replace some cars and less traveling in the first place so less cars overall.
Even if you charge your EV from a solar panel it still has a huge carbon footprint, the car, the solar panel, the road, etc all have a footprint, not just the 60% reduction in the carbon footprint of the fuel.