A Brazilian company called Nemus is using proceeds acquired by selling NFTs to preserve the Amazon rainforest.
The company, that owns 410 square kilometers (158 square miles) of forest, is granting buyers unique sponsorship of different sized tracts.
Its founder Flavio de Meira Penna said token holders will not own the land itself, but will have access to key information about its preservation, from satellite imagery to licensing and other documentation.
NFT sales platforms use the blockchain technology behind cryptocurrencies, and transform anything from illustrations to memes into virtual collectors' items that cannot be duplicated.
By selling NFTs, Nemus is allowing buyers to sponsor the preservation of specific areas of jungle and regenerate clear-cut areas and foster sustainable development.
Flavio de Meira Penna said Nemus had sold 10 per cent of an initial offer of tokens for 8,000 hectares on the first day.
"My guess is this will accelerate rapidly in coming weeks," Penna said, adding that blockchain technology would ensure transparency in the use of the funds.
Hammered by climate change and relentless deforestation, the Amazon rainforest is losing its capacity to recover and could irretrievably transition into savannah, with dire consequences for the region and the world.
Researchers warned that the results mean the Amazon could be approaching a so-called "tipping point" faster than previously understood.
Climate models have suggested that global heating, which has on average warmed Earth's surface 1.1 degrees Celsius above preindustrial levels -- could by itself push the Amazon past a point of no return into a far drier savannah-like state.
If carbon pollution continues unabated, that scenario could be locked in by mid-century, according to some models.
The plots being sold by Penna's company vary in size from a quarter of a hectare to 81 hectares (0.6 to 200 acres), which buyers will be able to locate with online maps.
NFTs for the smallest plots sell for $150 and the largest fetch $51,000, said Penna, who is hoping to raise $4 million to $5 million to buy an additional 2 million hectares of land already under negotiations in the municipality of Pauini in Amazonas state.
Along with preserving the forest, Penna said the funds would support sustainable development efforts such as harvesting acai berries and Brazil nuts by local communities in Pauini, which is the size of Belgium.
Each token comes with artwork of an Amazon plant or animal and is processed by San Francisco-based Concept Art House, a content developer and publisher for NFTs.
Critics have questioned the value of NFTs for environmental causes because tokens using the blockchain technology require intense computing power, driving up demand for electricity generation that releases climate-warming greenhouse gases.
Penna dismissed that view, saying preservation of threatened areas of the Amazon far outweighs the environmental cost of NFT transactions.