Interesting article outlining the detriments (massive energy consumption and carbon dioxide emission) inherent with proof-of-work algorithms such as Bitcoin and Ethereum.
This is one of the primary reasons we have selected proof-of-stake for the Aptum project. Additional to this, proof-of-stake as approached via our Pure-Proof-of-Stake (PPoS) algorithm fosters network security and decentralization by rewarding only active participants with little financial barrier to entry.