The environmental impact of aviation occurs because aircraft engines emit heat, noise, particulates and gases which contribute to climate change and global dimmining. Airplanes emit particles and gases such as carbon dioxide (CO₂), water vapor, hydrocarbons, carbon monoxide, nitrogen oxides, sulphur oxides , lead and black carbon which interact among themselves and with the atmosphere.

Despite emission reductions from automobiles and more fuel-efficient and less polluting turbofan and turboprop engines, the rapid growth of air travel in recent years contributes to an increase in total pollution attributable to aviation. From 1992 to 2005, passenger kilometers increased 5.2% per year. And in the European Union, greenhouse gas emissions from aviation increased by 87% between 1990 and 2006.

Comprehensive research shows that despite anticipated efficiency innovations to airframes, engines, aerodynamics and flight operations, there is no end in sight – even many decades out – to rapid growth in CO₂ emissions from air travel and air freight, due to projected continual growth in air travel. This is because international aviation emissions have escaped international regulation up to the ICAO triennial conference in October 2016 agreed on the CORSIA offset scheme, and because of the lack of taxes on aviation fuel worldwide, lower fares become more frequent than otherwise which gives a competitive advantage over other transportation modes. Unless market constraints are put in place this growth in aviation's emissions will result in the sector's emissions amounting to all or nearly all of the annual global carbon dioxide emissions budget by mid-century, if climate change is to be held to a temperature increase of 2 ?C or less.