"I'm not completely in favor of it, because of the energy consumption it requires," he explains.

Selling artwork in the form of NFTs (non-fungible tokens, in French) uses the same technology as cryptocurrencies like bitcoin.

The buyer receives a verified digital token, proving that the work is an original.

The boon for artists is that if their work appreciates in value and is resold, they receive a percentage of each future sale.

"If someone else buys my NFT, I automatically get a share of that money," says vonMash, in his studio in north Johannesburg.

Whereas in the traditional art market, if a buyer pays a hundred dollars and then "resells the work for 100,000, I wouldn't receive a penny" of this added value.

What worries vonMash like other artists is how these digital tokens are verified.

Visual artist vonMash poses for a portrait at his studio in Springs, South Africa, February 7, 2022 LUCA SOLA AFP/Archives

Ownership of the artwork is authenticated by mathematical puzzles so complex that the calculations require entire warehouses of computers.

Companies that solve these puzzles are rewarded with new tokens, and their solutions add a "block" to the authentication chain.

These calculations consume large amounts of energy, often produced by coal-fired power plants.

Most NFTs are currently traded on a platform called Ethereum.

Technology watchdog Digiconomist estimates that Ethereum uses as much electricity as the whole of the Netherlands, with a carbon footprint comparable to that of Singapore.

Annoyed K-pop fans

"The energy it takes for proof of authentication of the artwork is insane," vonMash points out.

These climate concerns are drawing harsh criticism against NFTs.

In South Korea, K-pop fans launched a vigorous campaign last year against the projects of well-known groups like BTS and ACE.

A work by South African visual artist von Mash, in Springs, South Africa, February 7, 2022 LUCA SOLA AFP/Archives

"Essentially, NFTs are a giant pyramid scheme that destroys the environment," assures a widely retweeted comment from @ChoicewithACE, typical of posts that prompted the group to rescind its offer.

BTS's music label, Hybe, has postponed their launch, seeking greener alternatives.

In South Africa, concern for the environment goes without saying for many artists.

The Tree collective has created a platform for artists to sell NFTs and then collaborate with an organization in Cape Town called Greenpop that plants trees to offset the carbon emitted.

Fhatuwani Mukheli claims that this system encouraged him to sell two of his NFTs.

“The world is constantly changing,” says the artist in his loft in the bustling center of Johannesburg.

"If I stick to what I know, the bus will leave without me."

For vonMash, the solution is to bypass Ethereum to place his works on a platform called Cardano, using a different authentication system.

Rather than solving ever more difficult puzzles - consuming electricity - companies can simply donate the tokens they already have.

In fact, they use their money in the form of cryptocurrency to guarantee the authenticity of a piece of digital art.

If someone tries to manipulate the system or simply makes a mistake, he can lose his financial participation in the network.

The technology behind it can be confusing, but social impact consultant Candida Haynes says "to cut it short, there are NFTs with options that are less harmful to the environment."

“At the end of the day, blockchain developers also have to commit to sustainability. And be concerned about keeping less geeky people, including artists, informed about it,” she says.

© 2022 AFP