This is just more environmental theatre. I completely believe that global warming is an existential threat to the planet. However if every airliner was grounded tomorrow the net reduction in world wide emissions would be about 3%. This is not going to move the needle. The biggest irony IMO is an equivalent to 10 % capacity reduction in emissions could be achieved by streamlining the incredibly byzantine and inefficient EU air traffic control system to reduce wasted flight time. Of course that would mean everyone in the EU would have to cooperate and each countries pet ANS might have to give up some control. So much easier to just put that in the "too hard" box and just artificially capacity constrain an airport for a feel good but ultimately pointless exercise in politics
