I looked relatively deeply in to this area when starting an asset exchange ~2011. My conclusion at that time was that existing carbon trading / offsets tokens were basically non-fungible due to disparate definitions from different regulators. Nominal assets ranged from honor-system self-declarations to heavily audited. The resulting asset types were found to be effectively illiquid, despite a rush to open exchange platforms and media talk of trading schemes, owing to lack of buy-side demand. Individually the systems were mostly only useful for gaming local regulators. I doubt their primary purpose today has changed from multinationals greenwashing their dirty operations with suitably distracting levels of misdirection.
California and Quebec carbon allowances markets are now linked (trading as CCA), and Washington State is expected to join. I researched that market thoroughly and it’s not perfect but very well structured. It’s mostly carbon allowances, not offsets (offsets don’t really reduce total emissions). CCAs trade on the ICE exchange and there are regular scheduled auctions. Arguably more liquid than most stocks.
At about that time I came into contact with a carbon offsets brokerage which European royalty had backed. I wondered if what they were actually selling was the opportunity to rub shoulders and network with some big hitters. That company was sold for a lot of money before the carbon market crashed last time for a range of reasons which I don’t think have been resolved.
