Well. @solairitas on our very own Hive blockchain! Plans to use hive to buy land and make a solar farm and the revenue from that will be going back in to hive for its supports down the line :D

There is also a project called seeds (https://www.joinseeds.com/) which have something to do with helping the planet, I am not that much into, so I don't know. Let me know if you want to join, I might be able to get you an invite.

Not crypto related, but a project called Ecotree aims to plant trees from investment, meaning you will get money back when the trees are harvest. If thats interested.