Oh asteroid mining with slow electric engines would offload SOOOOOO much emissions and pollution. Granted we would have to build some sort of space elevator or platform which would be a global effort and cost hundreds of trillions in every stage. But once the main aspects were done, it would be very efficient.
Also it turns out asteroids are conveniently formed in layers like an onion. All the work of pulling veins of ore out of ground and rock is unnecessary, because the heavier elements are further towards the center of these much MUCH Smaller bodies than planets, and the lighter elements on on top. It would make it far far easier to find and harvest these minerals and resources than it is now. As most people are aware, rare earth minerals aren’t actually rare, they’re just so scarcely spread out over our crust.
All the minerals and resources we want that are actually from Earth’s formation are hundreds of miles below the surface, most likely in molten form in the mantle, because of how cosmic body formation works with density and gravity. The resources we are extracting were probably almost all deposited by asteroid, meoterite, and comet strikes, that also probably brought our oceans.
All this to say, these asteroid did the same thing Earth did, pulled their heavy materials to their cores, but these are much easier to crack and process than an entire planet. We don’t need to go all Ishimura from Dead Space with planet cracking, when we can just crack open tiny to small sized asteroids and harvest those valuable materials much more readily, in FAR FAR higher quantity than on Earth’s surface, and with very little environmental impact.