Global warming??

While moving around a petrol pump (station) in the city, this air pressure monitor caught my attention... the petrol pumps provide free air facility for the cars and generally drivers tend to tip the attendant, thus to avoid this they have put up this no tipping sign there but I tend to read between the lines on this with global context on global warming. Like Air saying to us "NO TIPs PLEASE" let me be as pure as I can....so true?