We run a site about buying carbon credits. And we're going to tell you that a large portion of the carbon offset market is broken. Here's why we think you should know that before you spend a dollar.

The 2023 Investigation That Changed Everything

In January 2023, a joint investigation by The Guardian, Die Zeit, and SourceMaterial analyzed Verra-certified REDD+ forest conservation projects — the most popular category of voluntary carbon credits. The findings were devastating:

  • Approximately 90% of the rainforest offset credits analyzed were "phantom credits" — they did not represent genuine carbon reductions
  • Projects routinely inflated their deforestation baselines, claiming more trees would be cut than was realistic, generating credits for "avoided" deforestation that was never going to happen
  • The peer-reviewed study behind this investigation (West et al., published in Science, August 2023) found that only 6% of REDD+ credits in their sample represented real emission reductions

The impact was immediate: Verra's CEO resigned. The voluntary carbon market contracted significantly. Major corporate buyers pulled back. And individual consumers — rightfully — lost trust.

Specific Projects That Failed

South Pole's Kariba project (Zimbabwe) was the world's most popular offset project, purchased by Gucci, Volkswagen, and McKinsey among others. The 2023 analysis suggested it dramatically over-credited its climate impact. South Pole also faced internal controversy when employees reportedly raised concerns that were suppressed.

Katingan Mentaya (Indonesia) was sold to major corporations as protecting peat swamp forest. Analysis showed the deforestation baseline was inflated — the threats were overstated. (Some analysts argue the project still has genuine biodiversity value, even if the carbon numbers were wrong.)

A 2024 study in Nature Communications found that forest-based offsets in the California compliance market had issued credits 30% in excess of actual carbon storage, partly due to wildfire losses and drought-related tree mortality that weren't properly accounted for.

The Additionality Problem

The fundamental challenge in carbon offsets is proving that an emission reduction would not have happened without offset funding. This is inherently counterfactual — you can't observe what would have happened in a parallel universe without the project.

Projects most vulnerable to additionality failures:

  • Renewable energy projects in countries that were already building renewables (e.g., Chinese wind farms that would have been built anyway due to government mandates)
  • Forest conservation in areas with low actual deforestation pressure
  • Projects that started operations before they obtained carbon credit certification

What Actually Works

The market's problems are concentrated in nature-based avoidance credits — particularly cheap REDD+ forest projects. But specific program types have strong evidence of genuine impact:

  • Refrigerant destruction (Tradewater): There is zero economic reason to destroy these gases without offset funding. Additionality is unambiguous.
  • Clean cookstoves and water filters (BURN, LifeStraw): Rural communities demonstrably can't afford these products without subsidy. The health and environmental co-benefits are measurable.
  • Engineered removal (CarbonCure, biochar, DAC): These technologies physically remove carbon from the atmosphere. No baseline estimation needed — the removal is directly measured.

How to Buy Responsibly

The offset market is getting better post-2023 — Verra is overhauling its REDD+ methodology, satellite verification (Pachama) is adding independent monitoring, and buyers are more demanding. But the responsibility is still on you to buy well:

  1. Avoid cheap forest credits ($3-8/ton) unless they have CCB Triple Gold certification AND independent satellite verification
  2. Prioritize programs where additionality is obvious — refrigerant destruction, cookstoves, water filters, engineered removal
  3. Look for recognized verification standards — Gold Standard, Verra VCS (post-2024 methodology), American Carbon Registry
  4. Check independent evaluators — Giving Green, Carbon Direct, and the Berkeley Carbon Trading Project all publish program ratings
  5. Remember that offsets complement reduction — they don't replace it. The most impactful climate action is still reducing your own emissions first.