A cryptocurrency built to look cleaner than bitcoin is facing a harder environmental accounting
Chia has long presented itself as a greener alternative to bitcoin by replacing proof-of-work mining with a proof-of-space-and-time model. Instead of relying on vast quantities of nonstop computation, the system uses storage capacity, rewarding users that devote empty disk space and keep it available over time. That pitch helped distinguish Chia from the heavy electricity demands that have made bitcoin a regular target in debates over energy use and emissions.
New research summarized by New Scientist now argues that the environmental advantage has been overstated by a wide margin. The reporting says Chia's annual carbon footprint likely falls between 0.584 and 1.402 million tonnes per year, with the average estimate putting emissions at roughly 18 times the company's claimed 50,000 tonnes.
The key issue is not just electricity at runtime
The study, led by Soraya Djerrab at the Higher School of Computer Science and Digital Technologies in Algeria, examined the full process involved in using Chia. That matters because the blockchain depends on two separate activities: plotting and farming. Plotting creates the data that is later stored, while farming involves keeping that data available and proving to the network that it still exists.
Those steps do not stress hardware in the same way. Plotting is memory- and processor-intensive, and it often relies on fast solid-state drives. Farming is comparatively lighter and can be done on slower hard disks. According to the researchers, the environmental story changes significantly once the hardware burden of plotting is properly counted.
The study found that plotting wears out substantial numbers of SSDs. That means the system's footprint is not only about the electricity used while drives are active. It is also about the embodied carbon tied to manufacturing replacement hardware. In other words, the environmental cost is partly baked into the devices Chia consumes along the way.
Why embodied emissions matter here
That distinction is central to the paper's conclusion. Djerrab told New Scientist that Chia did not include the energy used to create the hardware in its calculations. If a network structure pushes participants to buy and replace drives, then the carbon released before those devices are even plugged in becomes part of the real-world footprint of the system.
This is an important correction to simplistic claims about digital sustainability. A platform can reduce one kind of energy use while quietly shifting environmental impact elsewhere. Chia may require less continuous brute-force computation than bitcoin, but the study suggests that its dependence on storage hardware creates a different set of costs that cannot be ignored.
The researchers also used hardware fitted with accurate wattmeters to measure power consumption during different Chia tasks. That makes the result harder to dismiss as purely theoretical. The conclusion presented in the article is not simply that storage devices exist somewhere in the background, but that both device wear and measured power draw affect the ledger's environmental footprint.
A problem for the broader blockchain narrative
The challenge for Chia is partly technical and partly reputational. It was marketed as a direct answer to the disaster scenario associated with bitcoin's power demand. New Scientist notes that bitcoin is estimated to consume around 157 terawatt-hours per year, roughly comparable to the electricity use of Poland. Chia's appeal came from seeming to escape that model.
But the new figures suggest that moving away from proof-of-work does not automatically resolve climate concerns. It may simply shift them into supply chains, component turnover, and less visible forms of energy consumption. The article also says the average emissions estimate would put Chia two orders of magnitude above mainstream blockchains such as Ethereum.
That comparison matters because it widens the frame from a single company dispute to a broader question about how blockchains should be evaluated. Public claims about cleaner design often rely on narrow accounting choices. When those assumptions are broadened, the environmental gap between one architecture and another can shrink or even reverse.
What comes next
Chia Network management told New Scientist that the study's figures are "not wildly off," while also promising improvements. That response does not read like a full endorsement, but it is notable that the company does not appear to be dismissing the estimate outright. The conversation has therefore moved beyond whether Chia should be compared with bitcoin and toward how complete its own accounting has been.
The larger lesson is straightforward. In digital infrastructure, claims of efficiency rise or fall on system boundaries. If a technology depends on frequent hardware replacement or intensive setup work, those costs belong in the total. Chia may still differ sharply from bitcoin in mechanism, but the latest research suggests its green branding is harder to sustain when the full lifecycle of the network is taken into account.
This article is based on reporting by New Scientist. Read the original article.
Originally published on newscientist.com
