Everyone has heard that companies “buy carbon credits,” but how do carbon credits work behind the scenes? Every credible credit follows the same five-step lifecycle — and understanding it is the fastest way to tell a real climate asset from a marketing prop.
Step 1: A project is designed
Everything starts with a project that reduces, avoids, or removes greenhouse gases: a wind farm displacing coal power, a program protecting rainforest from logging, a plant capturing methane from a landfill, or a facility pulling CO2 straight from the air. The developer writes a project design document specifying the methodology it will follow — the recipe, published by a carbon standard, that defines exactly how climate benefit will be measured.
Step 2: The baseline is set
The project’s impact is measured against a baseline: what would have happened without it. If a forest was on track to be cleared, the avoided emissions are the difference between that expected deforestation and reality. Baselines are the most contested part of carbon markets — set them too generously and the project gets credit for tonnes that were never at risk. Modern methodologies use satellite data, regional deforestation rates, and conservative discounts to keep baselines honest.
Step 3: Independent verification
Before any credit exists, an accredited third-party auditor — a validation and verification body — checks the project on the ground and in the data. Did the trees get planted? Is the methane meter calibrated? Is the claimed reduction real, measurable, and additional? Only after verification does a standard such as Verra or Gold Standard approve issuance.
Step 4: Credits are issued into a registry
Each verified tonne becomes one credit with a unique serial number in a public registry. The registry is the market’s accounting backbone: it records who owns every credit, prevents the same tonne being sold twice, and timestamps the credit’s vintage (the year the reduction occurred). Anyone can look up a serial number and trace it back to the project.
Step 5: Sale and retirement
Credits are sold — directly by developers, through brokers and marketplaces, or on exchanges — and may change hands several times. The lifecycle ends at retirement: the buyer permanently cancels the credit in the registry and claims its tonne against their own emissions. A retired credit can never be resold. If a seller can’t show you a retirement record in your name, you haven’t offset anything.
Where it goes wrong — and how to check
The system fails when baselines are inflated, verification is shallow, or reversals (like a forest fire) erase stored carbon. The fix as a buyer is simple diligence: confirm the standard, read the project’s rating from an independent assessor, prefer recent vintages, and insist on registry retirement. Ask those questions and the five-step machine works the way it was designed to — moving real money to real tonnes.
