NFTs use so much energy due to the trillions upon trillions of small puzzles that must be solved in order to do anything with them. Many of the main NFT networks, including Ethereum, use a method called proof of work to create, sell and purchase NFTs.
Proof of work requires the use of electricity to complete many complex mathematical equations inside computers. This is done to ensure that no single person can dominate the system and make it more likely that they solve the problem. If someone’s computer completes the equation correctly, they gain ownership of the art through their name being added next to it on the blockchain.
The equations for a single transaction can occur in less than 30 seconds, according to a trading platform called Blockchain.com, meaning millions can be done simultaneously in a single day.
Ethereum, the main network used to mint, mine and exchange NFTs, uses an estimated 52.7 megatons of CO2 a year — comparable to the annual carbon footprint of the entire country of Sweden. A single transaction in Ethereum emits carbon levels similar to that of watching more than 20,000 hours of YouTube.
While it is possible for NFT creation to be sustainable and energy efficient, it isn’t likely according to Alex de Vries, a blogger and leading expert in the environmental impacts of NFTs.
“You have to ensure that whatever platform you're using is actually running an independent proof of stake, or some similar type of infrastructure,” de Vries said.
Proof of stake is a method of NFT mining and trading like proof of work, only instead of millions of computer equations, it utilizes a user’s wealth in cryptocurrency as collateral. The system randomly assigns ownership and the next space on the blockchain. Whoever doesn’t win loses their money.
An Ethereum blog post on Jan. 25 noted it was moving to proof of stake. No timeline was given as to when that might happen. de Vries said the company has been saying this shift will happen for years. But as of yet, he said, there's been no real sign of movement.
