Last week, a group of hackers stole hundreds of NFTs from a site called OpenSea, with an estimated final total falling at 254 tokens stolen. It was later revealed the hack was a phishing attack after OpenSea began to investigate. NFTs, or non-fungible tokens, have recently become highly popular products. Ownership of an NFT is certified on a blockchain, which serves as a digital record and denotes who owns specific tokens. NFTs are supposed to be one of a kind, ensuring the tokens remain rare. The tokens themselves vary widely in form. Although the most popular form of NFTs is images, services such as NBA Top Shot allow fans to purchase NFTs of videos showing their favorite plays. Even if an NFT is recreated, the blockchain shows who the owner of any particular piece of digital art is, which is supposed to ensure the original token retains its value. But as the OpenSea phishing scam indicates, there are numerous problems inherent in digital “ownership.”

The decentralized nature of the NFT market allows for the proliferation of scams and illegitimate tokens. It also seems reasonable to label NFTs, and cryptocurrencies at large, as a “bubble.” According to the EconoTimes, “investments in NFTs are highly speculative” and huge swings in demand have led to a highly unstable market. The continued growth in value of NFTs is heavily contingent on whether or not investors remain convinced of digital art’s value, further increasing their unstable nature. But even outside of the negative economic impacts NFTs can have, perhaps the worst aspect of the NFT boom has been the harm it has done to the environment.

Granted, it seems odd that cryptocurrency art could have such a serious impact on the environment and climate change. Most NFTs exist on the popular Ethereum blockchain. According to Susanne Köhler, a sustainable blockchain technology researcher at Aalborg University Copenhagen in Denmark, “Most NFTs operate on Ethereum, which is a proof-of-work blockchain.” Proof-of-work requires that NFT or cryptocurrency miners “compete against each other to mine a block” to secure a transaction, which requires massive amounts of electricity. What is worse is that the process is designed to use large quantities of energy. There is no third party that serves as the role of a bank in regulating transactions on the blockchain, so someone can only mine a block once they have solved complicated puzzles using extremely electrically inefficient methods. The rationale behind the inefficiency built into the blockchain is that the high-energy costs make it less profitable for someone to steal from the blockchain. All of this has led to unprecedented energy consumption in the rush to acquire more NFTs.

According to CBS News, Ethereum, the most-used NFT blockchain, is “currently estimated to consume roughly 44.94 terawatt-hours of electrical energy, which is comparable to the yearly power consumption of countries like Qatar and Hungary. [Ethereum] is responsible for about 21.35 metric tons of carbon dioxide released each year, comparable to the carbon footprint of Sudan.” Even individual NFTs require massive amounts of energy and have some impact on the environment. Memo Akten, a digital artist, “analyzed about 18,000 NFTs, finding that the average NFT has a carbon footprint equivalent to more than a month of electricity usage for the average person living in the European Union,” according to CBS News, and emissions released by NFT transactions are thought to be “10 times higher than that of an average Ethereum transaction.” The entire system of NFT transactions, from the medium they are bought and sold on to the tokens themselves, is producing an unsustainable rate of emissions. The global environmental situation is already dire by most accounts, and NFTs are only making it worse.

So, what can we do? NFTs are popular, but many digital artists have expressed their concern that NFTs are not environmentally sustainable. Köhler has proposed using a different blockchain that does not require proof-of-work transactions. One such blockchain that already exists is the Flow blockchain, which uses a proof-of-stake model rather than proof-of-work to secure transactions. Flow, by using proof-of-stake, removes the necessity of massive energy use. Instead, users have to move some of their cryptocurrency holdings onto the blockchain to ensure the digital receipts remain accurate. Ethereum has said for years that they plan to move away from the proof-of-work method to proof-of-stake, which could improve NFT-based energy efficiency by 99 percent. Of course, the best way to reduce the environmental harms caused by NFTs would be to stop buying them. But it seems that NFTs are here to stay, for better or for worse. Clearly, there are ways to ensure that the creation and purchase of digital art becomes more sustainable, but it remains up to blockchains like Ethereum to ensure sustainable methods are implemented.

Theodore Brita is a sophomore majoring in political science.