Every carbon offset bundles three promises: the tonne would not have been saved anyway, it will stay saved, and saving it here did not move the emission elsewhere. These are additionality, permanence, and leakage. Using cases from the CDM, California forests, and rainforest credits, the episode shows why a market paying for an imagined alternative future rewards the best storyteller. It also gives defenders their case.
Who's who
- Barbara Haya+4 more episodesBerkeley researcher whose 2009 paper framed measuring against an alternative future
- Kevin AndersonClimate scientist who wrote the 2012 Nature column on offsets
- Michael Wara+1 more episodeStanford law professor who critiqued early offset markets
- Lambert Schneider+2 more episodesÖko-Institut researcher on additionality in the CDM
- Thales West+1 more episodeResearcher using synthetic controls to test rainforest credits
- Edward Mitchard+1 more episodeLead author of a December 2023 rebuttal preprint
- Frances SeymourWorld Resources Institute fellow arguing integrity crises risk starving forests of finance
Where it happens
- Kyoto, Japan+2 more episodes1997 protocol that fixed a 100-year accounting convention for tonnes
- California+30 more episodesForest program with 100-year permanence and flat 20 percent leakage deduction
- Milan, Italy2003 conference that created expiring forestry credits
Timeline
- October 22, 2004The CDM Executive Board adopts its additionality test.
- December 2009Haya publishes Measuring emissions against an alternative future.
- March 2016A study finds 85 percent of CDM projects unlikely to be additional.
- August 6, 2024The Integrity Council rejects eight legacy renewable methodologies covering about 236 million credits.
- June 30, 2026The Climate Action Reserve adopts a 40-year commitment period.
Still debated
Estimates of how much REDD+ was real range from about 6 percent to 25 percent, and California's over-crediting is disputed by its regulator. Whether forty or a hundred years is the honest permanence promise, and whether insurance restores tonnes or only money, are also unresolved.
