This is what I was thinking. Something such as Algae Farms would be very productive in order to ensure Co2 was handled properly and we had a renewable resource

This is what I was thinking. Something such as Algae Farms would be very productive in order to ensure Co2 was handled properly and we had a renewable resource of fuel. Additionally, they can be handled nearly anywhere with the only requirement is water and compost. As for the fish/animals lost in such ecosystems, they likely can never be replaced but collecting DNA samples would at least allow us to remember our history.