I've seen many projects about this but it seems most of them are lacking on something. Carbon credit market is a Billion dollar industry and applying blockchain will be good for both industry.
The problem is that blockchain can be used correctly and amazingly in carbon credit market but it is such a huge entry barrier that any low effort would not create any dent into the market. If you want to somehow merge carbon credits market and crypto (well blockchain to be exact) than you would have to do it really big and get into it really highly otherwise it would mean there are no way you can even contact the people needed to get into this.
For example I can just want to start this but I wouldn't know even where to start. This means unless some huge company in the business already decides to do it, it won't happen.