I have tried for a while to find a web-host which can report an estimation of my environmental impact based on usage. I have not been successful and the project for which I needed this we had to go with self-hosting(which likely is less sustainable) and having to calculate this based on information from our ISP/electricity companies.

Lot's of hosting companies including all the large clouds have marketing pages about their sustainability efforts but only an obscure, expense, and inaccessible Azure service can provide CO2 pollution estimations from ones usage...