Towards an unbiased evaluation of environmental footprint

[zeuner]

Especially PoS-secured blockchain schemes often claim having a lower environmental footprint than Bitcoin because no mining is necessary. However, the question remains whether they could actually replace the schemes they compete against. So, I wonder whether there is any research on the environmental footprint of different blockchains in proportion to the value they can actually store or transfer (maybe measured by the market capitalization or similar metrics).

Any ideas?