Are all these scientists smoking something or what?
Man or anything on this planet, short of a moon sized meteor hitting it or Al Gore never shutting up, will never ever overtake plants. It's THE reason the atmosphere is made up of 21% O2 while only 0.04% is CO2 (which you can literally call zero point zero BTW)
Plants RULE earth or maybe liberals think all this green stuff is green colored people and cars? And that is not even counting the ocean plant life like algae.