How Does the Carbon Credit System Work: An In-Depth Exploration

The Basic Idea Behind Carbon Credits

A carbon credit represents one metric tonne of CO2 equivalent (CO2e) that a project reduces or removes from the atmosphere. To create this credit, a project can, for example, protect an existing forest from deforestation, plant new trees, pull carbon dioxide from the air, use renewable energy instead of fossil fuels, etc. There are many ways to reduce your company's carbon footprint and fight climate change.

The logic behind carbon credits is simple: Greenhouse gas emissions are a global problem, so a tonne reduced anywhere counts everywhere. Carbon credits let companies finance emissions reduction projects to compensate for the carbon emissions they can't eliminate from their own operations (known as Scope 1, 2 or 3 emissions).

The credit is the accounting unit that makes the reduction or removal process transferable. But for a credit to mean anything, the system behind it, which covers verification, issuance, tracking, and retirement, has to work properly. That's what we'll cover in the rest of this article.

The Lifecycle of a Carbon Credit: How the System Works Step by Step

So how do carbon credits work in practice?

Every credit moves through five stages, from the moment a project developer breaks ground to when a buyer completes the retirement process. Here's an overview of the carbon credits system.

Step 1: Project Development

It starts with a carbon project that's designed to reduce or remove emissions.

Examples include forest conservation (REDD+) and reforestation (ARR) projects, cookstove distribution programs, biochar facilities, direct air capture (DAC) plants, superpollutant reductions, and renewable energy projects that displace fossil fuels and help reduce greenhouse gas emissions at the source.

The developer designs the project against a methodology, which is a standardized set of rules published by a registry, that explains how the project must measure and prove its climate impact. Nature-based solutions, like forestry projects that protect existing forests or plant new ones, measure the amount of carbon the land can sequester over time. Technology-based removal projects rely on engineering data.

Step 2: Validation and Verification

Before a registry can issue credits, it must validate and verify the project.

Validation confirms the project's design matches the methodology. Verification audits the project's actual results. Both validation and verification are carried out by an accredited third-party auditor.

Registries like Verra, Gold Standard, the American Carbon Registry, or Climate Action Reserve oversee this process and keep official records. In fact, Verra's Verified Carbon Standard (VCS) supplies the largest share of credits on the voluntary carbon market, also known as the VCM.

This is also where "permittance" comes in. When a registry verifies a project, it permits the developer to issue a set number of credits based on the project's assessed climate impact.

Step 3: Issuance

Once permitted, the developer makes a request for credits to be issued.

Every issued credit is a serialized, tradable unit. For example, Verra's VCS program issues Verified Carbon Units (VCUs), and each one represents one tonne of CO2e.

It's also important to understand that credits carry vintages, which represent the year the GHG emissions reduction or removal happened. The market sometimes views different vintages from the same project to have different quality levels, even when the underlying project is the same.

Issued credits then enter the market where they're bought and sold.

Step 4: Trading

Participants exchange credits on two markets. On the primary market, developers sell new credits to their first buyers. On the secondary market, buyers sell previously purchased credits to other entities.

Buyers can purchase carbon credits through developers, brokers, exchanges, and registries. Carbon credit prices vary based on project type, quality, vintage, and broader market conditions.

Throughout the entire process, registries track credit ownership. That way, it's always clear who holds which credit, and retired credits aren't double-counted, which has a negative environmental impact.

Step 5: Retirement

This is the final step. When a buyer wants to claim the climate benefit that a carbon credit represents, they "retire" it. The credit is then canceled in the registry, so it's never bought, sold, or used again.

Retirement turns a transaction into a real climate claim. A credit that sits unretired in someone's account hasn't been "used". Retirement locks in the claim to a specific tonne of impact. Retirement also prevents double-counting. After all, once a credit is retired, only the retiring entity can claim the tonne.

Who's Who in the Carbon Credit System

A handful of players participate in the carbon credit markets. Let's look at the full ecosystem:

• Project developers: The group that designs and runs carbon projects that generate credits, from forestry NGOs that protect existing forests to engineered-removal startups.
• Registries: Organizations like Verra, Gold Standard, the American Carbon Registry, and Climate Action Reserve that publish methodologies, oversee verification, issue credits, and maintain the official record. Think of them as the bookkeepers for the entire carbon credit system.
• Verification bodies: Accredited third-party auditors that validate project designs and verify results.
• Buyers: Companies, governments, and individuals who purchase carbon credits to meet climate targets, achieve public net-zero goals, or comply with government regulations.
• Brokers, exchanges, and marketplaces: Intermediaries who connect buyers and sellers and provide the infrastructure to trade credits on the open market, similar to stocks and bonds.
• Ratings agencies and data providers: Independent assessors, including Sylvera, that evaluate credit quality. Registry issuance confirms a credit exists, but not how good the credit is.
• Investors: Entities who finance carbon asset development at the beginning of a project. They often accept early risk in exchange for a share of the credits or returns the project generates in the future.
• Traders: The people and institutions who buy and sell credits to profit from price movements. This group adds liquidity to the market without necessarily using the credits themselves.
• Standard-setters and governance bodies: Organizations like the Integrity Council for the Voluntary Carbon Market (ICVCM), which assesses registries and methodologies against its Core Carbon Principles, and the Science Based Targets initiative (SBTi) that sets rules for what counts as credible, and how companies can use credits toward their climate and energy policy commitments.

The Two Markets: Voluntary and Compliance

Carbon credits trade across two distinct markets: The voluntary market and the compliance market. Understanding the difference between them is essential to understanding how the system works.

The Voluntary Carbon Market (VCM)

In the voluntary carbon market, companies and individuals buy carbon offsets to meet self-set climate targets, support the transition to net zero, or manage their carbon footprints. Participation is not required.

That said, standard-setters increasingly shape how companies can use these credits. SBTi's current rules restrict companies from counting purchased credits toward near-term emission reduction targets, which limits their role to neutralizing residual emissions that a company can't eliminate on its own.

The VCM is where most nature-based solutions, like REDD+ and ARR, and newer carbon removal projects, like direct air capture and biochar, trade. It's flexible and fast-moving, but historically speaking, less regulated than compliance markets. As such, independent quality assessment is valuable.

Compliance Carbon Markets

Compliance markets exist because of regulation. Governments set emissions limits and require certain industries to hold allowances or credits to cover what they emit. The EU Emissions Trading System (EU ETS), California's cap-and-trade program, Japan's GX-ETS, and various carbon taxes across Latin America that accept credits for compliance are examples of these emissions trading systems.

The most common structure is known as "cap and trade". In a cap and trade system, companies receive a set number of allowances. If they emit less than their cap, they can sell the surplus. If they emit more, they have to buy additional allowances or credits to cover the difference.

Some compliance systems let companies use carbon credits from carbon projects to meet a portion of their obligation. For example, Colombia's carbon tax lets companies offset some of their own emissions liabilities with domestic credits. This is a form of carbon pricing that puts a direct cost on emitting greenhouse gases. As such, it gives regulated companies a financial reason to invest in energy efficiency, cleaner processes, and renewable energy projects instead of only paying for allowances.

Internationally, the Paris Agreement crediting mechanism creates its own compliance layer. Article 6.2 lets countries trade emissions reductions bilaterally. Article 6.4 establishes a UN-supervised crediting system, replacing the old Clean Development Mechanism, that countries and companies can use toward their national climate targets or compliance obligations.

How the Two Markets Are Converging

The line between the voluntary and compliance markets is blurring.

There are two main forces that drive the convergence. First, the voluntary market is becoming more regulated. It faces scrutiny from bodies like IOSCO and the CFTC, alongside integrity initiatives like the ICVCM and demand-side standards from SBTi. Second, compliance markets are expanding into new sectors and starting to accept high-quality voluntary credits, especially carbon removal credits.

CORSIA, the scheme that covers international aviation, is a prime example. It's a global compliance program that uses voluntary-market-style credits. It's also converging with Article 6 as countries work out how credits can be authorized for use across both voluntary and compliance systems.

The big implication is that quality standards that started in the voluntary market are becoming the price of entry everywhere. The system is maturing toward a single, integrity-driven market.

The System's Weak Point: Not All Credits Are Equal

A carbon credit can be issued, tracked, and retired the right way – and still represent little climate impact. This is because registry issuance confirms that a credit followed a methodology. However, it does not confirm that the credit is high quality.

Three factors determine whether a credit represents a real tonne of avoided or removed carbon dioxide:

• Additionality: Would the reduction have happened if the carbon project didn't exist?
• Quantification (or carbon accounting): Is the claimed tonnage accurate, or is the project over-credited?
• Permanence: Will the sequestered carbon stay stored, or is there severe reversal risk?

This is why independent ratings exist. The party that issues and sells credits is incentivized to increase volume. Independent assessments tell buyers whether a credit is worth what it claims. It's a big part of what separates high-quality projects from ones that look credible on paper but fail to deliver.

As the system matures and voluntary and compliance markets converge, quality will continue to become the defining feature that separates credible carbon crediting programs from the rest.

Where Sylvera Stands

Sylvera is a carbon data platform that we designed to bring transparency to the carbon credit industry.

First, we have our independent Ratings. Using our vetted methodology and real-world data, our team rates carbon credits across carbon accounting, additionality, permanence, and co-benefits. As such, we provide the quality layer that the issuance-and-retirement system doesn't offer on its own. Equally as important, we don't sell carbon credits ourselves, so there's no conflict of interest in how we rate them.

Also worth mentioning, the Sylvera platform assesses projects across registries and project types on both the voluntary and compliance markets, which gives buyers a consistent view of quality.

Moving beyond ratings, we provide pricing, supply, and policy data that helps participants navigate carbon credit markets as a whole. In other words, we answer more than the quality question. You can use our platform to understand where the market is going and how you should react.

Finally, our Biomass Atlas solution, calibrated against $10M+ in ground-truth lidar across 250,000+ hectares, delivers forest biomass data at scale. It not only powers our Ratings, but also works as a standalone product that developers, registries, governments, and investors use for independent verification.

Understanding how carbon credit systems work is the first step. Knowing which credits to trust is the next one. Request a demo to see how Sylvera can help you navigate the carbon credit system with confidence. Or, sign up for free to explore our ratings right now.