Air Quality

Overview of Aviation Sector

  • The number of flights increased by 8% between 2014 and 2017, and grows by 42% from 2017 to 2040 in the most-likely forecast.
  • Technological improvements, fleet renewal and increased operational efficiency have been able to partially counterbalance the impact of recent growth, but there has still been an increase in overall emissions since 2014.
  • The environmental efficiency of aviation continues to improve and, by 2040, further improvements are expected in average fuel burn per passenger kilometre flown (-12%).
  • By 2040, CO2 and NOX emissions are predicted to increase by at least 21% and 16% respectively.

Technology and Design

  • Recent certification data demonstrates that advanced technologies continue to be integrated into new designs.
  • New engine PM standard will become applicable on 1 January 2020.
  • New technologies (e.g. supersonic and urban mobility aircraft) need to be carefully integrated into the aviation system to avoid undermining progress in mitigating environmental impacts.

Air Traffic Management and Operations

  • Airport arrival flow and taxi-out operational efficiencies have remained fairly stable over the past years.
  • The full potential from operational initiatives is not always achieved due to conflicting air navigation requirements (e.g. safety, environment, economic, capacity).


  • Emissions charges are used extensively, but the low level of charges (less than 1% of airline operating costs) is unlikely to affect the fleet operating at airports.
  • Involvement of stakeholders is crucial to identifying balanced mitigation measures, and can be done through a process such as Collaborative Environmental Management, which has already been implemented at 25 airports.

Aviation Environmental Impacts

  • There are good estimates for most pollutants emitted by aviation related activities that influence air quality and subsequent health effects, although knowledge gaps remain (e.g. on the impact of ultrafine particles).