Ecological responsibility

For the environment of tomorrow

Acting responsibly with regard to the environment is part of our corporate culture. We are committed to sustainable action toward the environment and future generations.

Harmful emissions from burning kerosine

All the aircraft used in civil aviation today operate entirely on kerosine. As this energy source combusts, it creates carbon dioxide (CO2 ). One ton of kerosine produces 3.15 tons of CO2 as well as water vapour and nitrogen oxide. These gases change the climate, and nitrogen oxide also affects air quality near the ground.

Greenhouse gases and pollutants produced by the combustion of jet fuel
Greenhouse gases and pollutants produced by the combustion of jet fuel

Fuel dumping

Fuel is dumped in large quantities only if an aircraft has to make an emergency landing shortly after take-off and must therefore drastically reduce its weight. This occurs between once and three times a year, and within the SWISS fleet is possible only with the Airbus A340.

Noise emissions

From a technical aspect, aircraft noise is caused by the engines. Hot and cold air meet here at very high speeds. Mechanical processes inside the engine create additional noise. Aerodynamics are responsible for the typical "rushing" sound that occurs as air flows over uneven points on the aircraft.

Investigations have shown that people perceive noise differently today than they did in earlier times. Our tolerance level has fallen continuously, and noise now irritates us more quickly than it once did. The same noise level can cause very different reactions in different people, based on the visibility and size of the aeroplane, the time of day, individual sensibilities, and general attitudes towards aviation and air travel.


SWISS takes its responsibility towards the environment extremely seriously, and follows the objectives of the International Civil Aviation Authority IATA. Specifically, they are:

  • By 2020: to improve fuel efficiency by 1.5% annually
  • From 2020: any growth in air travel should be CO2 neutral
  • By 2050: to halve CO2 emissions over 2005


In order to achieve our targets, SWISS bases its environmental strategy on these four pillars:

Technological progress

New aircraft types produce less CO2. This is why the old Airbus A330-200 fleet had to give way to new A330-300 models. This reduces kerosene consumption by 13% per passenger. From 2016, we will be replacing our European fleet (Avro RJ) with Bombardier type C series aircraft. New technology makes these aircraft 25% more efficient than their predecessors.

SWISS supports research into alternative fuels, and is an active member of the Roundtable on Sustainable Biofuels (RSB) of the École Polytechnique Fédérale de Lausanne. The aim of the RSB is to develop a sustainability standard for alternative fuels.

Operational measures

The more efficient a flying process is, the less of a burden it is on the environment. For instance, high-performance flight management systems can help to better utilise high-altitude winds. Systematic loading provides the optimum aerodynamics. And when the situation allows, SWISS pilots on the Airbus A340 switch off two of the four engines after landing and taxi to their stand position on the two remaining engines. Find out more in the Lufthansa Balance.

Efficient infrastructures

Better utilisation of airspace, airports and flight safety can help to significantly reduce CO2 emissions from aviation. Unfortunately, airways are only rarely efficient because each country controls its own airspace individually. The European Commission wants to intervene here. The project "Single European Sky" would help to save up to 10 million tons of CO2 every year – enough fuel to keep the entire SWISS fleet flying for three years. SWISS is involved in the technology of the project, and together with Skyguide and Zurich airport has implemented the pilot project "Greener Wave".

Economic instruments

SWISS is committed to a global and fair system for treating aviation emissions. This system rewards active environmental care and facilitates fair global competition. Furthermore, every SWISS passenger can commit to individual voluntary compensation for the CO2 emissions they cause through "myclimate".

CO2 emissions and kerosene consumption

SWISS has greatly reduced its specific CO2 emissions since 2003. Today the figure is over 20% less per 100 passenger kilometres. In order to achieve this goal, SWISS has invested billions in new aircraft types, used lighter materials, and improved flight processes and its flight loads.

Noise emissions

In aviation, noise pollution on the ground is represented as a noise carpet. The area where the defined limit is exceeded is shaded out.In the past 25 years, the much-affected area around Zurich airport has shrunk by two-thirds even though aircraft movements have almost doubled. Newer, much quieter aircraft have dramatically reduced the number of persons affected by noise.

Daytime noise carpet
Development of the daily noise carpet since 1967