An artist lists their artwork online and a customer purchases it.

**0.028** kg of CO2

Footprint based on Etsy’s carbon footprint for non-shipping activities: 2.7 million kg of CO2 for fewer than 100 million packages in 2018.

The artist prints the work and packages it up.

**0.13** kg of CO2

The artist drives it to their closest shipping store, 2 mi away.

**0.82** kg of CO2

The average gas-powered car in the US emits 0.4 kg of CO2 per mile driven.

The store sends the package to the local hub 5 mi away, where it is sorted.

**0.08** kg of CO2

A diesel truck gets 10.2 miles per gallon. We assume the package is one of 200 being transported and the hub’s emissions are the same as a sorting facility.

From the hub, the package is sent to the airport, 10 mi away.

**0.08** kg of CO2

A diesel truck gets 10.2 mpg. We assume the package is one of 200 being transported and the hub’s emissions are the same as a sorting facility.

The package is flown—along with many others—to the main sorting facility in Louisville, Kentucky, 660 mi away.

**0.096** kg of CO2

Based on a 0.5 lb package flown on a fully loaded Boeing 767 freighter with a 132,000 lb capacity.

The package is sorted and loaded onto another plane.

**0.05** kg of CO2

At peak, UPS Worldport has a 50 megawatt power demand and sorts 416,000 packages per hour.

That plane flies to the closest sorting facility to the customer, 1,800 mi away.

**0.22** kg of CO2

Based on a 0.5 lb package flown on a fully loaded Boeing 767 freighter with a 132,000 lb capacity.

From that facility, the package is sent to a local hub, 10 mi away, where it is sorted onto a delivery truck.

**0.11** kg of CO2

Total emissions: 2.304 kg of CO2. That’s similar to driving 5.6 mi in the US’s average gasoline-powered car.

**0.69** kg of CO2

Based on a truck making 170 deliveries on a residential route of 100 mi.

All together, shipping a digital print to an online customer causes 2.3 kg of CO2 emissions. Driving a typical gasoline-powered car in the US 100 mi causes 41 kg of CO2 emissions.

41 kg CO2

2.3

The artist finds a website that will facilitate her creating the NFT. She simply uploads her artwork, titles it, and clicks a button to create, or “mint,” it.

**Unclear**

Many of the steps in minting an NFT have an unknown carbon footprint.

This minting transaction is then added to a list of un-confirmed crypto transactions. The list contains all the incoming crypto activity, from simple buying and selling to more complex actions, like embedding the record of a digital artwork.

**Unclear**

Many of the steps in minting an NFT have an unknown carbon footprint.

A miner selects a subset of transactions to block together. Transactions are not added into the master ledger one by one. Instead, they’re bundled together in groups known as blocks. The master ledger is known as a blockchain because it is made up of these blocks.

**Unclear**

Many of the steps in minting an NFT have an unknown carbon footprint.

In order to add this block to the blockchain, this miner must race against time—and other miners—to solve a cryptographic puzzle. They use trial and error to rapidly generate random numbers checking each one to test if it is the solution. Top-of-the-line hardware can make hundreds of millions of guesses per second.

**This** is what makes crypto-art so environmentally unfriendly. There isn’t just one miner trying to add this block to the blockchain. There are thousands of them, many are huge operations running massive networks of computers in China, the Arctic, or elsewhere churning away trying to find the solution to each puzzle.

To calculate the carbon impact of adding this block to the blockchain, all the energy expended by all miners is counted.

**83** kg of CO2

Carbon footprint per Memo Akten.

The miner who first produces a correct solution to the puzzle first wins!

Miners check if the solution is correct. The process confirming a solution is much less energy intensive than finding it in the first place. If it’s confirmed, the miner’s block of transactions is added to the blockchain.

**Unclear**

Many of the steps in minting an NFT have an unknown carbon footprint.

The winning miner is paid in cryptocurrency for their services.

**Unclear**

Many of the steps in minting an NFT have an unknown carbon footprint.

The artwork now exists as an NFT, ready to be sold to a customer.

Every subsequent transaction for this NFT follows the exact same series of events. On average:

- Every bid creates 23 kg of CO2
- Every sale, 51 kg of CO2
- Every transfer, 30 kg of CO2

Each must be added to a block, and the puzzle must be solved and verified. Over its lifecycle, the average NFT will accrue a stunning footprint of 211 kg of CO2, equivalent to driving 513 mi in a typical US gasoline-powered car.

**128** kg of CO2

The carbon footprint of a crypto transaction is relative to its complexity: more complicated transactions have a bigger footprint. Artist and programmer Memo Akten calculated the carbon footprints used here.

For both scenarios the carbon-emitting life cycle may never end. The NFT may go on being bought and sold via blockchain transactions forever. The print could continue to be shipped to new buyers. Both could expand their carbon footprints indefinitely.

Although we can’t estimate the carbon footprint of each step of the NFT minting process, we do know the print would have to be bought and sold at least 91 times to be as carbon emitting as one average sale of an NFT and that driving a car 100 mi releases just 20% of the emissions of the average NFT sale.

211 kg CO2

41

2.3