THE DIRTY WORLD OF NFTS 

An NFT is a unique cryptocurrency token that can take the form of pretty much anything digital — art, a GIF, or even Twitter CEO Jack Dorsey’s first tweet. (For a more detailed look at what an NFT actually is, check out this breakdown.) There have been some initial estimates of how much power an NFT uses up and, consequently, how much planet-heating pollution that generates.

That website used to let people click through the estimated greenhouse gas emissions associated with individual NFTs until creator Memo Akten took it down on March 12th. Akten, a digital artist, had analyzed 18,000 NFTs and found that the average NFT has a carbon footprint somewhat lower than Space Cat’s but still equivalent to more than a month’s worth of electricity for a person living in the EU. 

But here’s why there’s probably a hell of a lot of greenhouse gas emissions tied to NFTs: they’re largely bought and sold in marketplaces like Nifty Gateway and SuperRare that use the cryptocurrency Ethereum. Ethereum, like most major cryptocurrencies, is built on a system called “proof of work” that is incredibly energy hungry. There’s a fee associated with making a transaction on Ethereum — and, ironically, that fee is called “gas.”