A project combining carbon credits and crytocurrencies would tokenize carbon credits, which could then be traded on a blockchain as a cryptocurrency.  The idea behind it is to make carbon credits more tradeable and accessible to a wider range of investors, and therefore increase the demand for carbon credits.  

Many are totally unaware of the recent agreements with the past year or so which are transitioning these markets from voluntary to mandatory.  These mandatory markets will mandate entire commercial segments to purchase carbon credits in the open market to offset their carbon emissions.  This represents a ground floor investment opportunity with practically limitless potential, versus a fixed supply.