Ключевые слова: aeronautics, air, air pollution, aircraft, airplane, atmosphere, aviation, climate, cloud formation, clouds, co2, co2 tax, condensation trails, crisis, energy waste, exhaust fumes, exhaust scandal, flight, fly, flying, freedom, fuel crisis, global warming, happiness, high altitude air, ice crystals, ionosphere, jet, oil crisis, oxygen, plans, science, sky, smoke, speed, stratosphere, tax, technology, transportation, travel, vacation, vacation destination, vacation plan,