A proof-of-work cryptocurrency with climate impact wired into its incentive layer: 20% of every transaction fee routed to verified tree-planting programs, with the ledger itself serving as the public audit trail for where the money went.
The point was to make the environmental commitment structural rather than promotional: not a pledge some foundation could quietly walk back, but a rule enforced by the protocol and legible to anyone reading the chain. An early experiment (2013) in pointing a network’s incentives at something outside itself.