To me this reads as trees are found to create a fuel naturally when in flooded areas and we need to find a way to use it for power like the NASA methane rocket that burns clean. It means we should find a way to plant trees in and around cities and use that to provide clean power for cities "IF" and only if we can collect it cheaply without hurting the trees or the oxygen they release which would be a huge plus for cities also. Trees are ,"yeah I sound like a greeny", a future that is preferable to hearing the whining of leftist on oil and nuclear like they have a real clue on how most of it works when done properly.