I do believe there are many better proof systems available at the moment, and I thought its emissions would be higher than 0.2%. Though if fossil fuels account for the majority of global carbon emissions, and banks providing the majority of fossil fuel investments, banks should surely account for a much larger portion of global emissions.

There is an argument to be made that Bitcoin could end up producing more carbon emissions if it already produces this much with a much lower transaction capacity than most banking systems. However, systems like the Lightning Network <https://wiki2.org/en/Lightning_Network> build on top of Bitcoin by settling transactions before they ever reach the blockchain, slashing fees and bundling possibly hundreds or thousands of transactions into one, so the number of payments that actually occur could be much greater than it seems.