busy skies

aircraft airline airliner airlines airplane airplanes airport airports around aviation blue bottleneck business busy capacity carbon city climate clogging co2 congestion connecting connection connections delay delays destination earth emission emissions energy environment environmental exhaust flier fliers flight flights fly flying fossil fuel fuels gasoline global globalization gridlock holiday holidays jam jams jet modern plane planes pollute polluting pollution problem route routes skies sky tourism touristic traffic transit transport transportation travel travelling trip urban vacation world worldwide