If the unit cost is higher than the maximum a manufacturer or retailer can charge, it won't be produced at all. This results in a market failure, similar to the one China's experiencing with their energy market, where the price of coal is 4x what it was earlier this year.

I'm not an economist, but I'm curious about this topic.

If, say, an iPhone cost $20k (because of emissions and slave/inhumane labor), obviously us normal folks (or poor folks) wouldn't own one, but would they still be produced for the grotesquely wealthy among us or would they just be scrapped or would the supply chain optimize for the new cost-structure and stop using slave labor to bring it down to a more reasonable price?