Series: Repricing Carbon — A Buyer’s Guide to the New Voluntary Market
- The Year Carbon Credits Stopped Being Free (you are here)
- Inside a Carbon Credit: What “High Quality” Actually Means
- Ratings Aren’t New. Carbon Ratings Are.
- How a Carbon Buyer Thinks in 2026
- The Reform Loop
For most of the last fifteen years, buying a carbon credit was one of the simpler sustainability decisions a company could make. It helps to start with what a credit actually is. One carbon credit represents one metric ton of carbon dioxide that a project claims to have either kept out of the atmosphere or pulled back out of it. A company that wanted to offset its emissions could buy a stack of these credits to match its footprint.
For a long time they were inexpensive. A credit from a forest-protection project often sold for somewhere between one and fifteen dollars a ton, depending on the project and the year. At those prices, the process was straightforward. A company could choose a project, pay for the credits, note the purchase in its annual report, and move on. There was not much reason to look closely at what sat behind the number.
That began to change in January 2023.
The Guardian, Die Zeit, and SourceMaterial published a joint investigation into rainforest credits issued under Verra, the largest registry in the voluntary carbon market. A registry is the body that approves a project’s accounting method and issues the credits. The investigation reported that more than 90% of the rainforest credits it reviewed were “phantom credits” that likely did not represent real emissions reductions. Verra disputed how the analysis was done, and the debate over the methodology is genuine and still ongoing. But for the people who actually sign purchase orders, the technical argument was beside the point.
In the weeks that followed, buyers who held rainforest credits started asking a question they had not needed to ask before. Do we actually own anything real?
That question did not go away. It did not disappear when Verra updated its rainforest methodology, and it did not disappear when the price of nature-based credits fell. It became a standard part of how companies buy.
What actually broke
The investigation did not destroy the voluntary carbon market. It removed an assumption.
The assumption was that the registry’s stamp was the buyer’s protection. If Verra, or Gold Standard, or another major registry had issued the credit, the credit was treated as good. The registry had reviewed the project. The registry had checked the accounting method. The credit was real because the institution behind it said so.
That was never quite what the registries were built to do. They are not buyer-protection bodies. They are the infrastructure that makes a market possible. They approve accounting methods, accredit the auditors who verify projects, and run the ledger that tracks credits. What they do not do is judge how well an individual project performs against the method it claims to follow. They do not catch inflated baselines, where a project overstates how much carbon it is really saving. They do not catch weak monitoring. They were never designed to.
For years that gap did not seem to matter, because few people were looking. The market was small, the buyers were quiet, and the press was focused elsewhere. The Guardian investigation made the gap impossible to ignore.
The reputational repricing
Carbon credits were not only cheap. They were also low-risk to be associated with. For most of the market’s history, those two things held together. The price was modest, and the reputational exposure was close to zero.
Over the course of 2023, the second half of that started to come apart. Being publicly tied to a credit that turned out to be low-integrity became something a company could lose real value over. Brand teams began asking questions that used to belong to the climate team. Legal teams began asking questions that used to belong to no one. This did not happen on a single day. It built over the months after the investigation, as more reporting followed and more buyers grew cautious.
The shift shows up in the price data. At their 2022 peak, many nature-based credits, meaning credits from projects like forest protection and reforestation, traded in the low-to-mid teens of dollars per ton. By 2024, a lot of those same credits were changing hands for a dollar or two. Across the secondary market, nature-based prices fell roughly 80% from that peak. That drop was not the market giving up on climate action. It was the market starting to separate credits it could defend from credits it could not.
Engineered removal credits moved the other way. These are credits from projects that physically capture and store carbon, through methods like direct air capture, biochar, or turning carbon into rock through mineralization. Demand and prices for these climbed. Not because the technology had suddenly matured, but because the story behind them was easier to tell. A buyer could explain, in plain terms, what the credit had done. These credits often cost a few hundred dollars per ton rather than a few dollars, but a buyer could stand behind one in a board meeting.
That is what repricing looks like. The market did not collapse. It started paying for things it had previously taken for granted.
The infrastructure that did not exist
When a market reprices around trust, the first thing it needs is a way to measure trust.
Other markets solved this problem long ago. The corporate bond market does not assume that companies are honest about their risk of default. It relies on Moody’s and S&P to flag when they are not. The stock market does not assume that companies report their earnings accurately. It relies on auditors and analysts to catch the ones that do not. The ESG investing market did not really function until firms like MSCI and Sustainalytics made it possible to rate companies on something other than what those companies said about themselves.
The voluntary carbon market had no equivalent layer. The registries issued credits. The buyers bought them. The auditors confirmed that the registry’s checklist had been followed. No one had the job of telling a buyer that a particular project, issued under a valid method and run by a credible developer, was still a weak credit.
That role exists now. Independent ratings firms such as Calyx Global, BeZero, and Sylvera grew up in the late 2010s and early 2020s, right as the market was starting to need them. The Guardian investigation did not invent this category. It made the category unavoidable.
A carbon rating is not the same as a registry approval. A rating is a buyer-side judgment about how likely a specific credit is to represent what it claims to. It scores the project, not the method. It looks at execution risk, whether the baseline is credible, whether the carbon will actually stay stored, and how well the project is monitored. It assumes the registry did its part, then asks whether that part was enough.
It is the same two-step question the bond market asks every day. Has the borrower followed the rules? Yes. Should I lend them money at this rate? That is a separate question.
What this means for buyers in 2026
Three things are true now that were not true in 2022.
First, the question “is this credit real?” finally has an answer a buyer can defend, and that answer no longer comes from the registry. It comes from independent ratings, from third-party project assessment, and from a buyer’s own due diligence.
Second, the price of a credit has started to track its quality, not just its category. A high-integrity nature-based credit can now sell at a real premium over a low-integrity one. That separation in price did not exist before, and it is the clearest sign that the market is starting to work.
Third, the work itself has moved. Buying carbon credits is no longer a sustainability-team task with a finance signature at the bottom. It is a cross-functional risk decision that runs through legal, brand, and procurement. The team that buys credits in 2026 looks less like a CSR working group and more like a credit committee.
A type of purchase that was cheap and low-risk for fifteen years now carries the same level of scrutiny as any other decision on the balance sheet. That is the repricing, and it is not going to reverse.
The next question is the one every buyer eventually reaches. What actually makes a carbon credit high quality? The answer is more specific than most of the market assumes, and most credits fail at least one part of it.
That is Part 2.
A note from the author. I am a writer who cares about sustainability, and when it comes to carbon credits I am still very much a learner. There are a lot of people who know this market far better than I do, and I have real respect for the work they have put into building it. If I got something wrong in here, I apologize, and I would genuinely like to hear about it so I can learn and correct it. I am writing this to start a conversation, not to have the last word. That is the whole point. This is a learning experience for me too, and the conversation is what moves all of us forward. If this piece helped you, share it. If you see it differently, even better. Let’s talk.