Environmental impact of aviation

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Aviation has an environmental impact . Harmful consequences are based on pollutant emissions , aircraft noise and surface sealing at airports . The burning of fossil fuels in aircraft with combustion engines produces harmful and climate-affecting gases as well as changes in cloud cover, whichcontributeto global warming .

Pollutant emission

Composition of emissions

Contrails over Georgia

Kerosene is the fuel that is used in all common jet engines. Gasoline (mostly AVGAS ) is used in aircraft engines that work on the 4-stroke principle . As with all petroleum-based fuels, the combustion of aviation fuels also produces emissions .

The following example shows the approximate emission of gases and particles in kilograms for a 150-seater touring aircraft (state of technology from 1995) with two engines during one hour of flight at cruising altitude. The numerical values ​​relate to the entire aircraft, i.e. include both engines. For new aircraft that will be delivered from 2015, it can be assumed today that the fuel requirement is around 30% lower.

Throughput through the engine: 850,000 kg of air sucked in and 2,700 kg of kerosene.
During this time, 130,000 kg of hot air (core engine) and 722,700 kg of cold air (bypass flow) leave the engine.
Of this, 8500 kg are carbon dioxide , 3300 kg water vapor , 30 kg nitrogen oxides , 2.5 kg sulfur dioxide , 2 kg carbon monoxide , 0.4 kg hydrocarbons and 0.1 kg fine particles .

The largest shares of emissions are thus accounted for by carbon dioxide and water vapor. These are not toxic, but are climate-relevant. Water vapor and carbon dioxide make up about 10% of the total emissions; the remainder is mostly expelled heated air. The combustion of kerosene also emits toxic substances, mainly carbon monoxide, nitrogen oxides and sulfur dioxide, as well as carbon in the form of soot .

Loading and refueling an aircraft at Helsinki Airport

Growth in air traffic emissions

The lower prices of flights and their easy availability have led to an enormous increase in air travel as a whole, thus multiplying the greenhouse gas emissions caused by traffic . Throughout Germany, emissions from air traffic rose by 85% between 1990 and 2014, from almost 15 million tons in 1990 to around 26-27 million tons in 2014. The specific greenhouse gas emissions from air traffic in 2010 were 1,540 g CO 2 equivalent / tonne-kilometer and result not only from pure CO 2 emissions, but also result from other climate-damaging effects from nitrogen oxides, soot, contrails and cirrus clouds caused by air traffic. The current annual growth rates of 7.1% in air traffic cancels out the savings from more economical engines. This means that the engines are optimized in terms of pollutant emissions, but with more and more flights and aircraft, the emissions increase more (see rebound effect ).

Effects of Air Traffic Emissions

Toxic Effects

In a study from 2010 based on model calculations, the premature deaths of people caused by aircraft emissions in cruise are estimated at around 8,000 per year worldwide, not taking into account the climate impacts. According to this, the proportion of the total of premature deaths due to air pollution is around 1%. On average, the victims lose 7.5 years of life to fine dust and nitrogen oxides. Some politicians complain that "the toxicological long-term effects of kerosene, its combustion residues and reaction products as well as their additive and synergistic effects have not been adequately investigated". According to information provided by the federal government in 2012, air quality in Germany is monitored within a radius of 20 km from all airports. The limit values ​​of the 39th Federal Immission Control Ordinance ( 39th BImSchV ) are decisive . The federal states are responsible for monitoring.

Contribution to global warming

The carbon dioxide leads to the absorption of thermal energy in the atmosphere , which is reflected from the earth's surface, thus increasing the anthropogenic greenhouse effect . The water vapor, the emission of which is visible as contrails at great heights , can lead to condensation of the water vapor already present in the atmosphere, so that this stimulation leads to increased cloud formation; this effect depends on the weather situation. A study from the USA in connection with the flight ban after September 11, 2001 showed that contrails have measurable effects on the weather . Immediately after the attacks, air traffic was almost completely suspended for a few days.

Radiative forcing through cloud formation induced by air traffic (simulation for 2006 with ground projection of the flight paths)

Overall, the effects of air traffic contribute around 4–5% to current global warming . The contrails and cirrus clouds caused by air traffic are probably the most important. The contribution of CO 2 emissions makes up about a third, that of nitrogen oxide emissions is a little over 5% net. The emitted water vapor itself only has a slightly warming effect, which is offset by an approximately equally high cooling effect of the fine dust emissions. The exact climate effect of the cloud formation induced by air traffic depends strongly on flight altitude, travel time (day or night), the atmospheric conditions along the route (including air temperature, concentration of ice crystals, existing clouds and condensation nuclei ) and the composition of the fuel. It has the most pronounced warming effects over North America, Europe and East and Southeast Asia, where air traffic is densest.

Admission situation

The ICAO introduced NO x limit values for engines for the first time in 1981 in order to improve the air quality at airports. In 1993 the limit value was tightened by the ICAO in order to reduce the NO x emissions of new engines by 20 percent from 1999 onwards. In 1999, the standard for NO x was reduced by an average of another 16 percent for newer engines with certification from 2003 (CAEP / 4) (ICAO 2007a). This standard is being updated by the ICAO. In the current guideline CAEP / 6, valid for engines from 2008, a limit value of 12 percent below CAEP / 4 is specified. With CAEP / 8 a further tightening came into force in 2010.

With the EU Emissions Trading Scheme (ETS), which came into force across Europe on January 1, 2005, the European Union is attempting to control the emission of greenhouse gases. In December 2006, the EU Commission proposed that air traffic be included in the EU emissions trading system. As of 2012, airlines will have to provide evidence of emissions rights on routes that touch EU airports.

In addition, passengers can offset their CO 2 emissions through donations to organizations such as Atmosfair , myclimate and Klima-Kollekte .

According to easyJet , since November 19, 2019, all CO 2 emissions caused by fuel combustion during the flight have been fully offset .

Limitation of pollutant emissions

Alternative fuel test flights

In order to counteract the growth in air traffic emissions, the German Aerospace Center (DLR) and NASA are investigating whether alternative fuels have the potential to make air traffic more environmentally and climate-friendly. To this end, DLR carried out test flights with alternative fuels as part of the ECLIF (Emission and Climate Impact of Alternative Fuels) project and was able to demonstrate some improvements due to the different composition of the fuel. Over 90% less fine dust, over 90% less sulfur oxide emissions and 30% less nitrogen oxide emissions were measured.

Alternative fuels, even if they were presented by the aviation industry as a sustainability solution, have so far not been able to establish themselves. Interest in biofuels , for example based on jatropha , camelina or animal fats, often waned again after a phase of greater attention.

Electric drive

Electric aircraft operate emission-free in flight operations. Another advantage is that compared to combustion engines, electric motors have a simpler design and are therefore lighter and require much less maintenance. The disadvantage of electric aircraft is that the batteries available to date have a lower energy density than conventional aircraft fuels. Therefore, the electric aircraft available today are limited in take-off mass and range. At the Paris Air Show 2019, the Eviation Alice, a 9-passenger airliner, was presented and is scheduled to go into commercial operation in 2022. Also, Airbus and Boeing are working on passenger aircraft with electric drive

CORSIA to regulate greenhouse gas emissions

In October 2016, the ICAO decided to introduce a global mechanism for regulating greenhouse gas emissions from international civil aviation. Under this, the aviation operators have to offset their emissions with so-called offset certificates. The CORSIA system will be implemented in three phases:

  • States can participate voluntarily in a pilot phase 2021–2023 and a first phase 2024–2026.
  • In the second phase 2027–2035, participation is mandatory for all countries. Exceptions are states with a very small proportion of global flight movements.

The greenhouse gas target in the sector is a CO 2 -neutral growth from 2020, but not an absolute reduction of CO 2 emissions. CORSIA is not intended to compensate for other climate impacts. These probably make up more than half of the radiative forcing caused by air traffic, which is decisive for global warming.

Environmental organizations criticize that the system comes too late and is not ambitious enough. In addition, it is completely open which standards should apply to the compensation certificates.

Efforts to introduce a kerosene tax

The French government wanted to propose a Europe-wide flight tax at the meeting of EU transport ministers on June 6, 2019 in Luxembourg. This tax could be added to airline tickets and kerosene or imposed by changes in EU emissions trading. According to the ORF report on June 6, 2019. There is also a European citizens' initiative with the aim of ending the existing tax exemption on kerosene. The deadline for this initiative is May 10, 2020.

Criticism of the tax exemption for kerosene

Environmental organizations criticize the tax exemption that continues to exist in view of the negative environmental impact of aviation. The German Federal Environment Agency emphasizes that a lack of kerosene taxation reduces incentives for airlines to use more fuel-efficient aircraft. For this reason, the authority classifies the lack of kerosene tax as an environmentally harmful subsidy , which in 2012 in Germany alone amounted to 7.083 billion euros. This sum corresponds to the tax loss due to the exemption of civil aviation from energy tax.

Critics of the lack of kerosene taxation point not only to global warming due to CO2 emissions, but also to other aviation emissions such as nitrogen oxide, fine dust, water vapor and contrail formation. Since the exhaust gases are emitted at great heights, the effects are serious. These other pollutants increase the damage caused by air traffic in the atmosphere by a factor of two to four, as the organization atmosfair has calculated.

The introduction of a state tax on turbine fuel is demanded by environmental protection and transport associations and European rail transport companies either at national or European level, with reference to improved fairness of competition between the modes of transport and the consistent inclusion of environmental externalities in the tariffs of air transport. Environmental organizations such as Verkehrsclub Deutschland see a ticket tax as a step in the right direction to eliminate the considerable distortions of competition, but the goal must continue to be the taxation of kerosene.

Ecological comparison of the means of transport

In an ecological comparison of the means of transport in Germany under realistic utilization, the contribution of airplanes to climate change per passenger- kilometer was significantly higher than that of other means of transport: converted into CO 2 emissions compared to coaches and trains by more than five times. The consumption of primary energy in liters per person was more than double. Aviation is responsible for almost five percent of the man-made climate effect worldwide, and in Switzerland in 2015 for over 18 percent. If the development continues as before, this proportion will increase to almost 22 percent by 2020.

Rethink air travel perks

In addition to the currently extensive tax exemption for kerosene, there are other benefits for commercial air traffic. For example, buying an aircraft in Europe is exempt from sales tax if the aircraft is used for international flight routes (Directive 2006/112 / EC).

Aviation shame: Refraining from air travel

'Flugscham' (from Swedish 'flygskam', in English 'flight shame') describes the concept that people, after they have become aware of the harmfulness of air travel, completely or at least partially forego it. The term has spread since the end of 2017, the concept has been demonstrably implemented by individuals since 1990. In Sweden, the number of passengers fell in 2018 at the same time as the increasing popularity of 'flygskam'. In Germany, there was no decline in the first half of 2019 either. Airlines responded in 2019 by announcing that they want to offset the CO 2 emissions, even though they are aware that this does not really solve the emissions problem.

Aircraft noise

A Qantas Airways Boeing 747-400 approaching London Heathrow Airport

Aircraft noise, i.e. the noise caused by airplanes and other aircraft , is one of the major environmental impairments caused by air traffic and has a different effect than rail or road noise due to its intermittent structure. More recent studies by the research association “Quiet Traffic” could not prove the different treatment of different types of traffic noise (e.g. rail bonus of 5 dB) as justified.

There are currently no valid limit values ​​for aircraft noise in Germany. However, aircraft noise has so far been the only source of noise that has been documented almost completely, since every commercial airport has to operate a continuous measuring system in accordance with Section 19a of the Aviation Act to monitor aircraft noise . The network of the German Aircraft Noise Service also creates documentation of aircraft noise exposure. V. (DFLD). The DFLD publishes these measured values, and its measured values ​​were independently checked by the Öko-Institut.

The Aircraft Noise Act of 1971 was discussed controversially for a long time and was not fundamentally changed until June 2, 2007. It sets noise limits for existing as well as for new and expanded airfields. With the new version of the law, residents of existing airports also have a legal right to passive noise protection - in contrast to those affected by rail or road noise, who have no legal rights for existing systems, but only for new construction and expansion measures. The Aircraft Noise Act now in force distinguishes between day and night protection zones as well as civil and military airfields.

A distinction is made according to the triggering flight phases or depending on place and time

The main sources of noise are the engines , but also the landing gear and the air flowing around the aircraft. Depending on the flight phase and the loading mass of the aircraft, these factors have different effects.

During take-off in aircraft with piston engines and in turboprops , noise is primarily generated at the propeller blades, and in jet and turbojet engines mainly as a result of the mixing of hot and fast exhaust gases with the surrounding air. Also in the area of ​​the fan, as well as the other engine blades, noise is generated by interference and irregularities in the air flow. Depending on the distance and type of aircraft, jet-powered passenger aircraft can be up to 90 dB (A) loud when taking off ( Boeing 747/400 at 300 m lateral distance). In conjunction with a heavily used international airport, this creates a high level of noise pollution for its immediate vicinity.

Exposure of the population to aircraft noise

Overall, the population's exposure to aircraft noise has changed significantly over the past 40 years. Although the individual aircraft have become computationally quieter, this effect is masked by the increasing number of flight movements. The noise reduction from aircraft has also mainly had an impact during the take-off process; the use of lighter construction materials means that less thrust is required and a steep climb can be achieved; there was little progress on land noise. Lately, at some airports (e.g. Frankfurt) an increase in noise has even been noticed - probably due to changed approach procedures.

Measures to reduce aircraft noise

Measures to reduce aircraft noise on the part of aircraft manufacturers are of a structural nature (e.g. further development of lightweight construction materials to reduce mass, development of turbofan engines with a high bypass ratio), airlines can take operational measures to reduce noise pollution (specification of noise abatement procedures ), which Air traffic control can help reduce noise pollution by planning the approach and departure routes over sparsely populated areas. In the ACARE research agenda and a consortium of European aircraft manufacturers and environmental institutes in the X-noise SOURDINE project, science and the European Union have set themselves the goal of halving the noise emissions of modern aircraft by 2020 through intensive development. Airport operators have also staggered the landing fees they levy according to noise criteria, so that it is more expensive for airlines to fly to these places with unnecessarily noisy aircraft (cf. ICAO's noise classification of aircraft ).

When operating permits for airports are issued or changed, the expected noise pollution is not measured, but calculated and the expected noise protection zones are calculated. The actual noise exposure may vary.

Effects of aircraft noise on people

Aircraft noise also has an impact on people's health. From 65 dB (A) health damage can occur, as numerous scientific studies show. The physical side effects are described as follows: The adrenal glands release the hormone adrenaline, which activates the so-called sympathetic nervous system. This nerve cord is located along the thoracic spine. The result: blood vessels constrict. The blood pressure rises. The heart rate increases. The body gets into a state of excitement. When the noise is over, the opponent of the sympathetic, the parasympathetic, takes over the regime. This nerve network controls the excitation back again. But with continuous noise or very frequent events, the body does not come to rest, the sympathetic nervous system remains active - and so the organs are in constant tension.

The possible consequences are: High blood pressure, cardiovascular diseases and other health impairments can occur, especially in the case of night aircraft noise , which is particularly important because of the particularly vulnerable night's sleep.

Noise also reduces physical and mental performance. Several studies show that children need more time for demanding tasks such as arithmetic and writing in a noisy environment. The error rate also increases. Noise disrupts communication: speaking in a noisy environment is exhausting. The brain needs more energy to differentiate and understand the words in the noise. Due to its frequency spectrum - compared to other sound sources - aircraft noise is a particular disruptive factor, as it covers wide areas of the human speech and hearing range.

Long-term aircraft noise study in Munich

The old Munich-Riem Airport moved to Erdinger Moos in 1992 . The entire flight operations were changed in a single night. This created the best conditions for an international long-term study on the subject of aircraft noise. 326 children who grew up either at the now closed Munich-Riem Airport or in the approach path of the new Munich Airport in Erdinger Moos were tested. The aim of the study was to determine the impact of aircraft noise on children who are still developing.

The noise study looked at various studies on the behavior of children in certain situations. For example, they were presented with very difficult tasks. The children affected by aircraft noise gave up more quickly than the children from quieter areas. Daily behavior was also negatively affected. The children were nervous, unbalanced, and fidgety. They found it much harder to concentrate on their tasks and quickly lost patience. Much more stress hormones were found in her urine than in the comparison group. The blood pressure also changed. The longer the children lived in the flight area, the higher their blood pressure values ​​rose, sometimes to dangerously high levels. In addition, sleep disorders occurred, especially during night flights.

The Munich study was followed by other comparative projects. They demonstrated increased aggression in the children. In the case of children who lived at the now closed airfield, on the other hand, their short and long-term memory and school performance improved after a while. The conclusion of the researchers: aircraft noise is harmful. Children who are exposed to aircraft noise for a long time have an increased risk of psychosomatic as well as cardiovascular diseases.

Land consumption & soil sealing

Frankfurt (Main) Airport

From a local perspective, airfields require large areas for runways, taxiways, parking areas, hangars and handling buildings. If these areas often consist of grass meadows in small squares, they are usually asphalted or concreted in airfields above a certain size ; this is always the case at international airports. The large asphalt areas then lead to soil sealing . Due to structural conditions, the groundwater is often lowered , which in turn disrupts the growth of plants in the area and affects the fauna. Something similar occurs with all construction projects of this type.

Compared to other modes of transport such as rail and road, the land consumption of air traffic in relation to the transport performance (measured in person- kilometers) per hectare of sealed area is very low. In the pacified, undeveloped areas of airfields, enclaves are often created in which biotopes with diverse flora and fauna can develop relatively undisturbed by humans. Protected biotopes are therefore available at many airfields.

See also

literature

  • Heinrich Mensen: Handbook of aviation . Springer Verlag, Berlin, Heidelberg, New York 2003
  • Wilhelm Pompl: Air traffic. An economic and political introduction. 4th ed., Berlin a. a. 2002
  • Christoph Alber: For legal protection against aircraft noise. In particular against the definition of so-called flight routes. Frankfurt 2004, ISBN 3-631-53172-9 .
  • Sonja Franke: Noise limit values ​​for planning commercial airports . Duncker & Humblot, Berlin 2003, ISBN 3-428-11052-8 .
  • Jan Ziekow (Ed.): Assessment of aircraft noise - regional planning - plan approval procedure . Lectures at the Fourth Speyer Planning Law Days and the Speyer Air Traffic Law Day ... for administrative sciences Speyer, Duncker & Humblot, Berlin 2003, ISBN 3-428-11164-8 .
  • Michael Kloepfer et al .: Living with Noise? Risk assessment and regulation of ambient noise in the traffic area . Springer Verlag, Berlin, Heidelberg 2006, ISBN 3-540-34509-4 .
  • Martin Hermann: Protection against aircraft noise when planning commercial airports in the light of constitutional law Duncker & Humblot, Berlin 1994, ISBN 3-428-08073-4 .

Web links

Individual evidence

  1. ^ Theo Rindlisbacher: Airplanes: Emissions, Air Quality and Climate . Ed .: Federal Office for Civil Aviation. No. 09/08 , 2008 ( doczz.nl [PDF; 1.6 MB ; accessed on February 19, 2018]).
  2. ↑ M. Pfitzner: Exhaust and noise emissions from aircraft. University of the Federal Armed Forces Munich, archived from the original on October 30, 2016 ; accessed on July 5, 2017 (presentation for a lecture).
  3. ↑ a b c Tillmann C. Gmelin: Summary presentation of the efficiency potentials in aircraft with special consideration of the current engine technology as well as the foreseeable medium-term developments ( Memento from March 9, 2017 in the Internet Archive ), March 25, 2008, on behalf of the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety
  4. ↑ Council of Economic Experts for Environmental Issues 2017. Change of direction required: Climate protection in the transport sector. Special report, p. 73 . Retrieved February 13, 2018.
  5. ↑ Increase in passenger numbers - record year for civil aviation In: srf.ch , January 18, 2018, accessed on January 18, 2018.
  6. ↑ Steven Barret, Britter, Rex and Waitz, Ian: Global Mortality Attributable to Aircraft Cruise Emissions . In: Environmental Science and Technology . 44, 2010, pp. 7736-7742. doi : 10.1021 / es101325r .
  7. ↑ Answer of the Federal Government to the minor question from the DIE LINKE parliamentary group of May 26, 2012
  8. ↑ spiegel.de: “Contrails affect the weather” , accessed on August 16, 2009
  9. ^ A b Lisa Bock and Ulrike Burkhardt: Contrail cirrus radiative forcing for future air traffic . In: Atmospheric Chemistry and Physics . July 2019, doi : 10.5194 / acp-19-8163-2019 .
  10. ↑ Jörgen Larsson, Anna Elofsson, Thomas Sterner, Jonas Åkerman: International and national climate policies for aviation: a review . In: Climate Policy . January 2019, doi : 10.1080 / 14693062.2018.1562871 .
  11. ↑ Michael Le Page: It turns out planes are even worse for the climate than we thought. In: New Scientist. June 27, 2019, accessed July 5, 2019 .
  12. ↑ a b Bernd Kärcher: Formation and radiative forcing of contrail cirrus . In: Nature Communications . May 2018, doi : 10.1038 / s41467-018-04068-0 .
  13. ↑ ICAO: Local Air Quality and ICAO Engine Emissions Standards
  14. ↑ icao.int: Committee on Aviation Environmental Protection (CAEP) , accessed April 20, 2017
  15. ↑ Stefan Eiselin: Easyjet passengers now fly climate-neutral. aerotelegraph.com, November 19, 2019, accessed November 19, 2019 .
  16. ↑ dlr.de: DLR flight tests on alternative fuels , accessed on April 23, 2017
  17. ↑ ccs-greenenergy.com: Clean Carbon Solutions GmbH. Alternative Fuels for Aviation - Green Fuel Project , accessed April 23, 2017
  18. ↑ P. Peeters, J. Higham, D. Kutzner, S. Cohen, S. Gössling: Are technology myths stalling aviation climate policy? In: Transportation Research Part D: Transport and Environment . tape 44 , 2016, p. 30–42 , doi : 10.1016 / j.trd.2016.02.004 .
  19. ↑ www.manager-magazin.de: This man wants to redefine flying, from June 19, 2019 , accessed on July 21, 2019
  20. ↑ Electric aircraft: Airbus and Siemens cooperation will end, June 9, 2019, accessed on August 11, 2019
  21. ↑ 2. What is CORSIA and how does it work? Retrieved February 21, 2017 (American English).
  22. ↑ Climate impact of air traffic , Federal Environment Agency 2012, PDF
  23. ↑ Climate protection in air traffic: Too late, too weak, too little serious | Germanwatch eV Retrieved on February 21, 2017 .
  24. ↑ Aviation industry postpones climate protection . In: klimaretter.info . ( klimaretter.info [accessed on February 21, 2017]).
  25. ↑ France wants to propose Europe-wide flight tax orf.at, June 6, 2019, accessed June 6, 2019.
  26. ^ Ending the aviation fuel tax exemption in Europe. In: EUROPEAN CITIZENS 'INITIATIVE. May 10, 2019, accessed June 6, 2019 .
  27. ↑ Philip Pramer: Why is it so expensive to travel by train and why is it so cheap to fly? In: derStandard.at. October 17, 2019, accessed on October 25, 2019 (Austrian German).
  28. ↑ Environmentally harmful subsidies in Germany. Umweltbundesamt, December 2016, p. 44. Accessed July 2, 2017.
  29. ↑ Anne Kretzschmar, Matthias Schmelzer: No flight: Everyone who flies is one too many . In: The time . May 31, 2019, ISSN  0044-2070 ( zeit.de [accessed June 6, 2019]).
  30. ↑ VCD: for maintaining the aviation tax
  31. ↑ Emissions data. Federal Environment Agency, July 25, 2016, accessed on January 23, 2018 .
  32. ↑ WWF air traffic: Climate pays the price for flying , WWF Switzerland, accessed on June 15, 2019
  33. ↑ Jasper Faber, Thomas Huigen: A study on aviation ticket taxes. In: transportenvironment.org. November 2018, accessed June 12, 2019 . Section "1.1 Policy xontext".
  34. ↑ All evidence can be found with the respective statements in the main article flight shame .
  35. ↑ German Aircraft Noise Service e. V.
  36. ↑ independent examination (PDF; 80 kB)