At least for CO2, emissions haven’t been outsourced much. At least, emissions in developed countries are still falling when adjusting for trade. Most of the rising emissions in developing countries like China and India are due to them getting richer rather than becoming the worlds factories. I don’t know how other pollutants compare. Likely worse as they are not an issue for western companies to care about so much.

On CO2: https://ourworldindata.org/consumption-based-co2