Non-fungible token: Unterschied zwischen den Versionen

== Criticism ==

=== Storage off-chain ===

NFTs involving digital art generally do not store the file on the blockchain due to its size. The token functions in a way more similar to a certificate of ownership, with a [[web address]] pointing to the piece of art in question, making the art still subject to [[link rot]].<ref name="dash"/>

=== Environmental concerns ===

NFT purchases and sales are enmeshed in a controversy regarding the high energy use, and consequent [[greenhouse gas emissions]], associated with blockchain transactions.<ref name="Calma">{{Cite web|last=Calma|first=Justine|date=2021-03-15|title=The climate controversy swirling around NFTs|url=https://www.theverge.com/2021/3/15/22328203/nft-cryptoart-ethereum-blockchain-climate-change|access-date=2021-04-15|website=The Verge|language=en}}</ref> A major aspect of this is the [[Proof of work|proof-of-work]] protocol required to regulate and verify blockchain transactions on public networks, which consumes a large amount of electricity.<ref>{{cite journal |last1=Krause|first1=Max|last2=Tolaymat|first2=Thabet|title= Quantification of energy and carbon costs for mining cryptocurrencies |journal=Nature Sustainability |date=2018 |volume=1 |pages=814 |url= https://www.nature.com/articles/s41893-018-0152-7.epdf?sharing_token=ogrkYYbTeyhxNtpO8VyD8tRgN0jAjWel9jnR3ZoTv0NdJEcpPQZqiP9V_5sRM6OFxFiXIrEiqGJgeMqL0bBy3oWWhgCPavrJMPApmX-akgSr_A5uSnPnPPEknP0vEMNn0cVObPWp1NK2O3ttOyulWBx5GKIPbWG95X0V8tpJk9M2Z4q-wzNau-UzDXnrmvGgenXNCUHI7lbX4j0i_fnP9qqMPxjbMls9G9YEFs7oL_A%3D&tracking_referrer=www.theguardian.com |doi=10.1038/s41893-018-0188-8|doi-access=free }}</ref><ref>{{cite journal|last1=Gallersdorfer|first1=Ulrich|last2=Klassen|first2=Lena|last3=Stoll|first3=Christian|title= Energy Consumption of Cryptocurrencies Beyond Bitcoin |journal=Joule |date=2020 |volume=4(9)  |url= https://www.cell.com/action/showPdf?pii=S2542-4351%2820%2930331-7 |doi=10.1016/j.joule.2020.07.013|pmc=7402366}}</ref> Estimating the [[carbon footprint]] of a given NFT transaction involves a variety of assumptions about the manner in which that transaction is set up on the blockchain, the economic behavior of blockchain miners (and the energy demands of their mining equipment),<ref>{{Cite web|last= deVries|first= Alex|date=2018-05-16|title= Bitcoin's Growing Energy Problem|url= https://www.cell.com/joule/fulltext/S2542-4351(18)30177-6|website=Joule|language=en}}</ref> as well as the amount of renewable energy being used on these networks.<ref>{{Cite web|last=Cuen|first= Leigh|date=2021-03-21|title=The debate about cryptocurrency and energy consumption|url= https://techcrunch.com/2021/03/21/the-debate-about-cryptocurrency-and-energy-consumption/|website=TechCrunch|language=en}}</ref> There are also conceptual questions, such as whether the [[carbon footprint]] estimate for an NFT purchase should incorporate some portion of the ongoing energy demand of the underlying network, or just the marginal impact of that particular purchase.<ref name=“De-Mattei”>{{Cite web|last=De-Mattei|first=Shanti Escalante|date=2021-04-14|title= Should You Worry About the Environmental Impact of Your NFTs?|url=https://www.artnews.com/art-news/news/nft-carbon-environmental-impact-1234589742/|access-date=2021-06-02 |website=Art News|language=en}}</ref> An analogy that's been described for this is the footprint associated with an additional passenger on a given airline flight.<ref name="Calma"/>

Some more recent NFT technologies use alternative validation protocols, such as proof of stake, that have much less energy usage for a given validation cycle. Other approaches to reducing electricity include the use of off-chain transactions as part of minting an NFT.<ref name="Calma"/> A number of NFT art sites are also looking to address these concerns, and some are moving to using technologies and protocols with lower associated footprints.<ref>{{Cite web|last=Matney|first=Lucas |date=2021-03-30|title= ConsenSys launches a more energy-efficient NFT ecosystem with a project from artist Damien Hirst as its first drop |url= https://techcrunch.com/2021/03/30/consenysys-launches-a-more-energy-efficient-nft-ecosystem-with-a-project-from-artist-damien-hirst-as-its-first-drop/ |access-date=2021-04-21|website=Techcrunch|language=en}}</ref> Others now allow the option of buying carbon offsets when making NFT purchases, although the environmental benefits of this have been questioned.<ref>{{Cite web|last= Di Liscia |first= Valentina |date=2021-04-05|title= Does Carbon Offsetting Really Address the NFT Ecological Dilemma? |url= https://hyperallergic.com/634236/does-carbon-offsetting-really-address-the-nft-ecological-dilemma/ |access-date=2021-04-21|website=Hypoallergic|language=en}}</ref> In some instances, NFT artists have decided against selling some of their own work to limit carbon emission contributions.<ref name=":10">{{Cite web|last=Howson|first=Peter|title=NFTs: why digital art has such a massive carbon footprint|url=http://theconversation.com/nfts-why-digital-art-has-such-a-massive-carbon-footprint-158077|access-date=2021-04-06|website=The Conversation|language=en}}</ref>