Found this old article from 2010 about Green Exchange LLC and how CO2 is a carbon market:

https://www.reuters.com/article/us-carbon-green-exchange/green-exchange-hires-key-staff-in-european-co2-push-idUSTRE64339420100504

Key sentences:

>LONDON (Reuters) - NYMEX’s carbon emissions marketplace Green Exchange LLC has opened a new office in London and hired key staff from competitors in a push to gain market share in the $100 billion European carbon market.

>Green Exchange is a joint venture among major carbon market players which include Goldman Sachs and Morgan Stanley.

Could extend the notable >>7810634 about BlackRock investing in climate change.