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Like other emissions resulting from fossil fuel combustion, aircraft engines produce gases, noise, and particulates, raising environmental concerns over their global impact and their local air quality effect. CO
2), the best understood greenhouse gas, and, with less scientific understanding, nitrogen oxides, contrails and particulates. Their radiative forcing is estimated at 1.3–1.4 that of CO
2 alone, excluding induced cirrus cloud with a very low level of scientific understanding. In 2018, global commercial operations generated 2.4% of all CO
Jet airliners have become 70% more fuel efficient between 1967 and 2007, and CO
2 emissions per Revenue Ton-kilometer (RTK) in 2018 were 47% of those in 1990. In 2018, CO
2 emissions averaged 88 grams of CO
2 per revenue passenger per km. While the aviation industry is more fuel efficient, overall emissions have risen as the volume of air travel has increased. By 2020, aviation emissions were 70% higher than in 2005 and they could grow by 300% by 2050.
Aircraft noise pollution disrupts sleep, children's education and could increase cardiovascular risk.Airports can generate water pollution due to their extensive handling of jet fuel and deicing chemicals if not contained, contaminating nearby water bodies. Aviation emit ozone and ultrafine particles, both health hazards, and general aviation burn Avgas, releasing toxic lead.
Aviation's environmental impact can be reduced by better fuel economy in aircraft or Air Traffic Control and flight routes can be optimised to lower non-CO
2 impact on climate from NO
x, particulates or contrails. Aviation biofuel, emissions trading and carbon offsetting, part of the ICAO's CORSIA, can lower CO
2 emissions. Aviation usage can be lowered by short-haul flight bans, train connections, personal choices and aviation taxation and subsidies. Fuel-powered aircraft may be replaced by hybrid electric aircraft and electric aircraft or by hydrogen-powered aircraft.
Airplanes emit gases (carbon dioxide, water vapour, nitrogen oxides or carbon monoxide − bonding with oxygen to become CO
2 upon release) and atmospheric particulates (incompletely burned hydrocarbons, sulfur oxides, black carbon), interacting among themselves and with the atmosphere. While the main greenhouse gas emission from powered aircraft is CO
2, jet airliners contribute to climate change in four ways as they fly in the tropopause:
In 1999, the IPCC estimated aviation's radiative forcing in 1992 to be 2.7 (2 to 4) times that of CO
2 alone − excluding the potential effect of cirrus cloud enhancement. This was updated for 2000, with aviation's radiative forcing estimated at 47.8 mW/m2, 1.9 times the effect of CO
2 emissions alone, 25.3 mW/m2.
In 2005, research by David S. Lee, et al, published in the scientific journal Atmospheric Environment estimated the cumulative radiative forcing impact of aviation at 55 mW/m2, which is twice the 28 mW/m2 radiative forcing impact of its CO
2 emissions alone, excluding induced cirrus cloud, with a very low level of scientific understanding. In 2012, research from Chalmers university estimated this weighting factor at 1.3–1.4 if aviation induced cirrus is not included, 1.7-1.8 if they are included (within a range of 1.3–2.9).
Uncertainties remain on the NOx–O3–CH4 interactions, aviation-produced contrails formation, the effects of soot aerosols on cirrus clouds and measuring non-CO2 radiative forcing.
In 2018, CO
2 represented 34.3 mW/m2 of aviation's effective radiative forcing (ERF, on the surface), with a high confidence level (± 6 mW/m2), NO
x 17.5 mW/m2 with a low confidence level (± 14) and contrail cirrus 57.4 mW/m2, also with a low confidence level (± 40). All factors combined represented 43.5 mW/m2 (1.27 that of CO
2 alone) excluding contrail cirrus and 101 mW/m2 (±45) including them, 3.5% of the anthropogenic ERF of 2290 mW/m2 (± 1100).
By 2018, airline traffic reached 4.3 billion passengers with 37.8 million departures, an average of 114 passengers per flight and 8.26 trillion RPKs, an average journey of 1,920 km (1,040 nmi), according to ICAO. The traffic was experiencing continuous growth, doubling every 15 years, despite external shocks − a 4.3% average yearly growth and Airbus forecasts expect the growth to continue. While the aviation industry is more fuel efficient, halving the amount of fuel burned per flight compared to 1990 through technological advancement and operations improvements, overall emissions have risen as the volume of air travel has increased. Between 1960 and 2018, RPKs increased from 109 to 8,269 billion.
In 1992, aircraft emissions represented 2% of all man-made CO
2 emissions, having accumulated a little more than 1% of the total man-made CO
2 increase over 50 years. By 2015, aviation accounted for 2.5% of global CO
2 emissions. In 2018, global commercial operations emitted 918 million tonnes (Mt) of CO
2, 2.4% of all CO
2 emissions: 747 Mt for passenger transport and 171 Mt for freight operations. Between 1960 and 2018, CO
2 emissions increased 6.8 times from 152 to 1,034 million tonnes per year.
Between 1990 and 2006, greenhouse gas emissions from aviation increased by 87% in the European Union.In 2010, about 60% of aviation emissions came from international flights, which are outside the emission reduction targets of the Kyoto Protocol. International flights are not covered by the Paris Agreement, either, to avoid a patchwork of individual country regulations. That agreement was adopted by the International Civil Aviation Organization, however, capping airlines carbon emissions to the year 2020 level, while allowing airlines to buy carbon credits from other industries and projects.
In 1992, aircraft radiative forcing was estimated by the IPCC at 3.5% of the total man-made radiative forcing.
As it accounts for a large share of their costs - 28% by 2007, Airlines have a strong incentive to lower their fuel consumption, reducing their environmental impact.Jet airliners have become 70% more fuel efficient between 1967 and 2007. Jetliner fuel efficiency improves continuously, 40% of the improvement come from engines and 30% from airframes. Efficiency gains were larger early in the jet age than later, with a 55-67% gain from 1960 to 1980 and a 20-26% gain from 1980 to 2000.
The average fuel burn of new aircraft fell 45% from 1968 to 2014, a compounded annual reduction of 1.3% with variable reduction rate. CO
2 emissions per Revenue Ton-kilometer (RTK) were more than halved compared to 1990, at 47%. The aviation energy intensity went from 21.2 to 12.3 MJ/RTK between 2000 and 2019, a 42% reduction.
In 2018, CO
2 emissions totalled 747 million tonnes for passenger transport, for 8.5 trillion revenue passenger kilometres (RPK), giving an average of 88 gram CO
2 per RPK. The ICAO targets a 2% efficiency improvement per year between 2013 and 2050, while the IATA targets 1.5% for 2009-2020 and to cut net CO
2 emissions in half by 2050 relative to 2005.
In 1999, the IPCC estimated aviation's radiative forcing may represent 190 mW/m2 or 5% of the total man-made radiative forcing in 2050, with the uncertainty ranging from 100 to 500 mW/m2. If other industries achieve significant reductions in greenhouse gas emissions over time, aviation's share, as a proportion of the remaining emissions, could rise.
Alice Bows-Larkin estimated that the annual global CO
2 emissions budget would be entirely consumed by aviation emissions to keep the climate change temperature increase below 2 °C by mid-century. Given that growth projections indicate that aviation will generate 15% of global CO
2 emissions, even with the most advanced technology forecast, she estimated that to hold the risks of dangerous climate change to under 50% by 2050 would exceed the entire carbon budget in conventional scenarios.
In 2013, the National Center for Atmospheric Science at the University of Reading forecast that increasing CO
2 levels will result in a significant increase in in-flight turbulence experienced by transatlantic airline flights by the middle of the 21st century.
2 emissions grow despite efficiency innovations to aircraft, powerplants and flight operations. Air travel continue to grow.
In 2015, the Center for Biological Diversity estimated that aircraft could generate 43 Gt of carbon dioxide emissions through 2050, consuming almost 5% of the remaining global carbon budget. Without regulation, global aviation emissions may triple by mid-century and could emit more than 3 Gt of carbon annually under a high-growth, business-as-usual scenario. Many countries have pledged emissions reductions for the Paris Agreement, but the sum of these efforts and pledges remains insufficient and not addressing airplane pollution would be a failure despite technological and operational advancements.
The International Energy Agency projects aviation share of global CO
2 emissions may grow from 2.5% in 2019 to 3.5% by 2030.
By 2020, global international aviation emissions were around 70% higher than in 2005 and the ICAO forecasts they could grow by over further 300% by 2050 in the absence of additional measures.
By 2050, aviation climate impacts could be decreased by a 2% increase in fuel efficiency and a decrease in NO
x emissions, due to advanced aircraft technologies, operational procedures and renewable alternative fuels decreasing radiative forcing due to sulfate aerosol and black carbon.
Air traffic causes aircraft noise, which disrupts sleep, adversely affects children's school performance and could increase cardiovascular risk for airport neighbours.Sleep disruption can be reduced by banning or restricting flying at night, but disturbance progressively decreases and legislation differs across countries.
The ICAO Chapter 14 noise standard applies for aeroplanes submitted for certification after 31 December 2017, and after 31 December 2020 for aircraft below 55 t (121,000 lb), 7 EPNdB (cumulative) quieter than Chapter4. The FAA Stage 5 noise standards are equivalent. Higher bypass ratio engines produce less noise. The PW1000G is presented as 75% quieter than previous engines. Serrated edges or 'chevrons' on the back of the nacelle reduce noise impact.
A Continuous Descent Approach (CDA) is quieter as less noise is produced while the engines are near idle power. dB per flight.CDA can reduce noise on the ground by ~1-5
Airports can generate significant water pollution due to their extensive use and handling of jet fuel, lubricants and other chemicals. Chemical spills can be mitigated or prevented by spill containment structures and clean-up equipment such as vacuum trucks, portable berms and absorbents.
Deicing fluids used in cold weather can pollute water, as most of them fall to the ground and surface runoff can carry them to nearby streams, rivers or coastal waters. 101 Deicing fluids are based on ethylene glycol or propylene glycol. :4 Airports use pavement deicers on paved surfaces including runways and taxiways, which may contain potassium acetate, glycol compounds, sodium acetate, urea or other chemicals. :42:
During degradation in surface waters, ethylene and propylene glycol exert high levels of biochemical oxygen demand, consuming oxygen needed by aquatic life. Microbial populations decomposing propylene glycol consume large quantities of dissolved oxygen (DO) in the water column. 2–23 Fish, macroinvertebrates and other aquatic organisms need sufficient dissolved oxygen levels in surface waters. Low oxygen concentrations reduce usable aquatic habitat because organisms die if they cannot move to areas with sufficient oxygen levels. Bottom feeder populations can be reduced or eliminated by low DO levels, changing a community's species profile or altering critical food-web interactions. :2–30:
Aviation is the main human source of ozone, a respiratory health hazard, causing an estimated 6,800 premature deaths per year.
Aircraft engines emit ultrafine particles (UFPs) in and near airports, as does ground support equipment. During takeoff, 3 to 50 × 1015 particles were measured per kg of fuel burned,while significant differences are observed depending on the engine. Other estimates include 4 to 200 × 1015 particles for 0.1–0.7 gram, or 14 to 710 × 1015 particles, or 0.1-10 × 1015 black carbon particles for 0.046–0.941 g.
In the United States, 167,000 piston aircraft engines, representing three-quarters of private airplanes, burn Avgas, releasing lead into the air.The Environmental Protection Agency estimated this released 34,000 tons of lead into the atmosphere between 1970 and 2007. The Federal Aviation Administration recognizes inhaled or ingested lead leads to adverse effects on the nervous system, red blood cells, and cardiovascular and immune systems. Lead exposure in infants and young children may contribute to behavioral and learning problems, lower IQ, and autism.
In February 2021, Europe's aviation sector unveiled its Destination 2050 sustainability initiative towards zero CO
2 emissions by 2050:
while air traffic should grow by 1.4% per year between 2018 and 2050.The initiative is led by ACI Europe, ASD Europe, A4E, CANSO and ERA.
Aviation's environmental impact would be mitigated by reducing air travel, route optimization, emission caps, short-distance restrictions, increased taxation, and decreased subsidies.
An improved Air Traffic Management system, with more direct routes than suboptimal air corridors and optimized cruising altitudes, would allow airlines to reduce their emissions by up to 18%. CO
2 emissions per year were caused by the lack of a Single European Sky. As of September 2020, the Single European Sky has still not been completely achieved, costing 6 billion euros in delays and causing 11.6 million tonnes of excess CO
ICAO has endorsed emissions trading to reduce aviation CO
2 emission, guidelines were to be presented to the 2007 ICAO Assembly. Within the European Union, the European Commission has included aviation in the European Union Emissions Trading Scheme operated since 2012, capping airline emissions, providing incentives to lower emissions through more efficient technology or to buy carbon credits from other companies. The Centre for Aviation, Transport and Environment at Manchester Metropolitan University estimates the only way to lower emissions is to put a price on carbon and to use market-based measures like the EU ETS.
A short-haul flight ban is a prohibition imposed by governments on airlines to establish and maintain a flight connection over a certain distance , or by organisations or companies on their employees for business travel using existing flight connections over a certain distance, in order to mitigate the environmental impact of aviation . In the 21st century, several governments, organisations and companies have imposed restrictions and even prohibitions on short-haul flights, stimulating or pressuring travellers to opt for more environmentally friendly means of transportation , especially trains .
Train connections reduce feeder flights.By March 2019, Lufthansa offered connections through Frankfurt with the Deutsche Bahn (AIRail Service) and Air France offered TGV connections through Paris. In October 2018, Austrian Airlines and the Austrian Federal Railways introduced train connections through Vienna Airport. In March 2019, the Dutch cabinet was working on an Amsterdam connection via NS International or Thalys. By July 2020, Lufthansa and Deutsche Bahn expanded their offer through Frankfurt Airport to 17 major cities.
Most international professional or academic conference attendants travel by plane, conference travel is often regarded as an employee benefit as costs are supported by employers.By 2003, Access Grid technology had hosted several international conferences. The Tyndall Centre has reported means to change common institutional and professional practices.
In Sweden the concept of "flight shame" or "flygskam" has been cited as a cause of falling air travel.Swedish rail company SJ AB reports that twice as many Swedish people chose to travel by train instead of by air in summer 2019 compared with the previous year. Swedish airports operator Swedavia reported 4% fewer passengers across its 10 airports in 2019 compared to the previous year: a 9% drop for domestic passengers and 2% for international passengers.
In 2016, the International Civil Aviation Organization committed to improve aviation fuel efficiency by 2% per year and to stabilise carbon emissions from 2020.To achieve these goals, multiple measures have been planned: more fuel-efficient aircraft technology; development and deployment of sustainable aviation fuels; Improved air traffic management; market-based measures like emission trading, levies, and carbon offsetting, the Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA).
Developed by the International Civil Aviation Organization (ICAO) and adopted in October 2016. Its goal is to have a carbon neutral growth from 2020. CORSIA uses Market-based environmental policy instruments to offset CO2 emissions: aircraft operators have to purchase carbon credits from the carbon market. Starting in 2021, the scheme is voluntary for all countries until 2027.
Financial measures can discourage airline passengers and promote other transportation modes and motivates airlines to improve fuel efficiency. Aviation taxation include:
Consumer behaviour can be influenced by cutting subsidies for unsustainable aviation and subsidising the development of sustainable alternatives. By September–October 2019, a carbon tax on flights would be supported by 72% of the EU citizens, in a poll conducted for the European Investment Bank.
Aviation taxation could reflect all its external costs and could be included in an emissions trading scheme.International aviation emissions escaped international regulation until the ICAO triennial conference in 2016 agreed on the CORSIA offset scheme. Due to low or nonexistent taxes on aviation fuel, air travel has a competitive advantage over other transportation modes.
An aviation biofuel or bio-jet-fuelor bio-aviation fuel (BAF) is a biofuel used to power aircraft and is said to be a sustainable aviation fuel (SAF). The International Air Transport Association (IATA) considers it to be one of the key elements to reduce the carbon footprint within the environmental impact of aviation. Aviation biofuel could help decarbonize medium- and long-haul air travel generating most emissions, and could extend the life of older aircraft types by lowering their carbon footprint.
Biofuels are biomass-derived fuels, from plants or waste; depending on which type of biomass is used, they could lower CO₂ emissions by 20–98% compared to conventional jet fuel.The first test flight using blended biofuel was in 2008, and in 2011 blended fuels with 50% biofuels were allowed in commercial flights. In 2019, the IATA was aiming for a 2% penetration by 2025.
Aviation biofuel can be produced from plant sources like Jatropha, algae, tallows, waste oils, palm oil, Babassu and Camelina (bio-SPK); from solid biomass using pyrolysis processed with a Fischer–Tropsch process (FT-SPK); with an alcohol-to-jet (ATJ) process from waste fermentation; or from synthetic biology through a solar reactor. Small piston engines can be modified to burn ethanol.
Sustainable biofuels do not compete with food crops, prime agricultural land, natural forest or fresh water. They are an alternative to electrofuels.Sustainable aviation fuel is certified as being sustainable by a third-party organisation.
In 2020, Airbus unveiled liquid-hydrogen-powered aircraft concepts as zero-emissions airliners, poised for 2035.Aviation, like industrial processes that cannot be electrified, should use primarily Hydrogen-based fuel.
The Potsdam Institute for Climate Impact Research reported a €800–1,200 mitigation cost per ton of CO
2 for hydrogen-based e-fuels. Those could be reduced to €20–270 per ton of CO
2 in 2050, but maybe not early enough to replace fossil fuels. Climate policies could bear the risk of e-fuel uncertain availability, and Hydrogen and e-fuels may be prioritised when direct electrification is inaccessible.
Besides carbon dioxide, aviation produces nitrogen oxides (NO
x), particulates, unburned hydrocarbons (UHC) and contrails. Flight routes can be optimised: modelling CO
2O and NO
x effects of transatlantic flights in winter shows westbound flights climate forcing can be lowered by up to 60% and ~25% for jet stream-following eastbound flights, costing 10–15% more due to longer distances and lower altitudes consuming more fuel, but 0.5% costs increase can reduce climate forcing by up to 25%. A 2000 feet (~600 m) lower cruise altitude than the optimal altitude has a 21% lower radiative forcing, while a 2000 feet higher cruise altitude 9% higher radiative forcing.
In UK, transportation replaced power generation as the largest emissions source. This includes aviation's 4% contribution. This is expected to expand until 2050 and passenger demand may need to be reduced.For the UK Committee on Climate Change (CCC), the UK target of an 80% reduction from 1990 to 2050 was still achievable from 2019, but the committee suggests that the Paris Agreement should tighten its emission targets. Their position is that emissions in problematic sectors, like aviation, should be offset by greenhouse gas removal, carbon capture and storage and reforestation.
In December 2020 the UK Climate Change Committee said that: "Mitigation options considered include demand management, improvements in aircraft efficiency (including use of hybrid electric aircraft), and use of sustainable aviation fuels (biofuels, biowaste to jet and synthetic jet fuels) to displace fossil jet fuel."The UK will include international aviation and shipping in their carbon budgets and hopes other countries will too.
A carbon offset is a means of compensating aviation emissions by saving enough carbon or absorbing carbon back into plants through photosynthesis (for example, by planting trees through reforestation or afforestation) to balance the carbon emitted by a particular action.
Some airlines have been carbon-neutral like Costa Rican Nature Air,or claim to be, like Canadian Harbour Air Seaplanes. Long-haul low-cost venture Fly POP aims to be carbon neutral.
In 2019, Air France announced it would offset CO
2 emissions on its 450 daily domestic flights, that carry 57,000 passengers, from January 2020, through certified projects. The company will also offer its customers the option to voluntarily compensate for all their flights and aims to reduce its emissions by 50% per pax/km by 2030, compared to 2005.
Starting in November 2019, UK budget carrier EasyJet decided to offset carbon emissions for all its flights, through investments in atmospheric carbon reduction projects. It claims to be the first major operator to be carbon neutral, at a cost of £25 million for its 2019-20 financial year. Its CO
2 emissions were 77g per passenger in its 2018-19 financial year, down from 78.4g the previous year.
From January 2020, British Airways began offsetting its 75 daily domestic flights emissions through carbon-reduction project investments. The airline seeks to become carbon neutral by 2050 with fuel-efficient aircraft, sustainable fuels and operational changes. Passengers flying overseas can offset their flights for £1 to Madrid in economy or £15 to New York in business-class.
US low-cost carrier JetBlue planned to use offsets for its emissions from domestic flights starting in July 2020, the first major US airline to do so. It also plans to use sustainable aviation fuel made from waste by Finnish refiner Neste starting in mid-2020.In August 2020, JetBlue became entirely carbon-neutral for its U.S. domestic flights, using efficiency improvements and carbon offsets. Delta Air Lines pledged to do the same within ten years.
To become carbon neutral by 2050, United Airlines invests to build in the US the largest carbon capture and storage facility through the company 1PointFive, jointly owned by Occidental Petroleum and Rusheen Capital Management, with Carbon Engineering technology, aiming for nearly 10% offsets.
Electric aircraft operations do not produce any emissions and electricity can be generated by renewable energy. Lithium-ion batteries including packaging and accessories gives a 160 Wh/kg energy density while aviation fuel gives 12,500 Wh/kg. 45:1 ratio. For Collins Aerospace, this 1:50 ratio forbids electric propulsion for long-range aircraft. By November 2019, the German Aerospace Center estimated large electric planes could be available by 2040. Large, long-haul aircraft are unlikely to become electric before 2070 or within the 21st century, whilst smaller aircraft can be electrified. As of May 2020, the largest electric airplane was a modified Cessna 208B Caravan.As electric machines and converters are more efficient, their shaft power available is closer to 145 Wh/kg of battery while a gas turbine gives 6,545 Wh/kg of fuel: a
For the UK's Committee on Climate Change (CCC), huge technology shifts are uncertain, but consultancy Roland Berger points to 80 new electric aircraft programmes in 2016–2018, all-electric for the smaller two-thirds and hybrid for larger aircraft, with forecast commercial service dates in the early 2030s on short-haul routes like London to Paris, with all-electric aircraft not expected before 2045. CO
2 share for aviation by 2050 if fuel efficiency improves by 1% per year and if there are no electric or hybrid aircraft, dropping to 3–6% if 10-year-old aircraft are replaced by electric or hybrid aircraft due to regulatory constraints, starting in 2030, to reach 70% of the 2050 fleet. This would greatly reduce the value of the existing fleet of aircraft, however. Limits to the supply of battery cells could hamper their aviation adoption, as they compete with other industries like electric vehicles.Lithium-ion batteries have proven fragile and fire-prone and their capacity deteriorates with age. However, alternatives are being pursued, such as sodium-ion batteries.
The International Civil Aviation Organization (ICAO) is a specialized and funding agency of the United Nations. It changes the principles and techniques of international air navigation and fosters the planning and development of international air transport to ensure safe and orderly growth. Its headquarters is located in the Quartier International of Montreal, Quebec, Canada.
Contrails or vapor trails are line-shaped clouds produced by aircraft engine exhaust or changes in air pressure, typically at aircraft cruising altitudes several miles above the Earth's surface. Contrails are composed primarily of water, in the form of ice crystals. The combination of water vapor in aircraft engine exhaust and the low ambient temperatures that exist at high altitudes allows the formation of the trails. Impurities in the engine exhaust from the fuel, including sulfur compounds provide some of the particles that can serve as sites for water droplet growth in the exhaust and, if water droplets form, they might freeze to form ice particles that compose a contrail. Their formation can also be triggered by changes in air pressure in wingtip vortices or in the air over the entire wing surface. Contrails, and other clouds directly resulting from human activity, are collectively named homogenitus.
The International Air Transport Association is a trade association of the world's airlines founded in 1945. IATA has been described as a cartel since, in addition to setting technical standards for airlines, IATA also organized tariff conferences that served as a forum for price fixing.
Carbon neutrality refers to achieving net-zero carbon dioxide emissions. This can be done by balancing emissions of carbon dioxide with its removal or by eliminating emissions from society. It is used in the context of carbon dioxide-releasing processes associated with transportation, energy production, agriculture, and industry.
Air travel is a form of travel in vehicles such as airplanes, jet aircraft, helicopters, hot air balloons, blimps, gliders, hang gliders, parachutes, or anything else that can sustain flight. Use of air travel has greatly increased in recent decades – worldwide it doubled between the mid-1980s and the year 2000. Modern air travel is much safer than road travel.
The use of energy is considered sustainable if it meets the needs of the present without compromising the needs of future generations. Definitions of sustainable energy typically include environmental aspects such as greenhouse gas emissions, and social and economic aspects such as energy poverty.
Jet fuel or aviation turbine fuel is a type of aviation fuel designed for use in aircraft powered by gas-turbine engines. It is colorless to straw-colored in appearance. The most commonly used fuels for commercial aviation are Jet A and Jet A-1, which are produced to a standardized international specification. The only other jet fuel commonly used in civilian turbine-engine powered aviation is Jet B, which is used for its enhanced cold-weather performance.
Climate change mitigation consists of actions to limit global warming and its related effects. This involves reductions in human emissions of greenhouse gases (GHGs) as well as activities that reduce their concentration in the atmosphere.
Chemically, black carbon (BC) is a component of fine particulate matter. Black carbon consists of pure carbon in several linked forms. It is formed through the incomplete combustion of fossil fuels, biofuel, and biomass, and is one of the main types of particle in both anthropogenic and naturally occurring soot. Black carbon causes human morbidity and premature mortality. Because of these human health impacts, many countries have worked to reduce their emissions, making it an easy pollutant to abate in anthropogenic sources.
Air transport in the United Kingdom is the commercial carriage of passengers, freight and mail by aircraft, both within the United Kingdom (UK) and between the UK and the rest of the world. In the past 25 years the industry has seen continuous growth, and the demand for passenger air travel in particular is forecast to increase from the current level of 236 million passengers to 465 million in 2030. One airport, Heathrow Airport, is amongst the top ten busiest airports in the world. More than half of all passengers travelling by air in the UK currently travel via the six London area airports. Outside London, Manchester Airport is by far the largest and busiest of the remaining airports, acting as a hub for the 20 million or so people who live within a two-hour drive. Regional airports have experienced the most growth in recent years, due to the success of low-cost carrier airlines over the last decade.
Sustainable biofuel is biofuel produced in a sustainable manner.
An aviation biofuel or bio-jet-fuel or bio-aviation fuel (BAF) is a biofuel used to power aircraft and is said to be a sustainable aviation fuel (SAF). The International Air Transport Association (IATA) considers it to be one of the key elements to reduce the carbon footprint within the environmental impact of aviation. Aviation biofuel could help decarbonize medium- and long-haul air travel generating most emissions, and could extend the life of older aircraft types by lowering their carbon footprint.
Climate change mitigation scenarios are possible futures in which global warming is reduced by deliberate actions, such as a comprehensive switch to energy sources other than fossil fuels. These are actions that minimize emissions so atmospheric greenhouse gas concentrations are stabilized at levels that restrict the adverse consequences of climate change. Using these scenarios, the examination of the impacts of different carbon prices on an economy is enabled within the framework of different levels of global aspirations.
The environmental impact of transport is significant because transport is a major user of energy, and burns most of the world's petroleum. This creates air pollution, including nitrous oxides and particulates, and is a significant contributor to global warming through emission of carbon dioxide. Within the transport sector, road transport is the largest contributor to global warming.
Carbon-neutral fuel is fuel which produces no net-greenhouse gas emissions or carbon footprint. In practice, this usually means fuels that are made using carbon dioxide (CO2) as a feedstock. Proposed carbon-neutral fuels can broadly be grouped into synthetic fuels, which are made by chemically hydrogenating carbon dioxide, and biofuels, which are produced using natural CO2-consuming processes like photosynthesis.
The fuel economy in aircraft is the measure of the transport energy efficiency of aircraft. Efficiency is increased with better aerodynamics and by reducing weight, and with improved engine BSFC and propulsive efficiency or TSFC. Endurance and range can be maximized with the optimum airspeed, and economy is better at higher altitudes. An airline efficiency depends on its fleet fuel burn, seating density, air cargo and passenger load factor, while operational procedures like maintenance and routing can save fuel.
The Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) is a carbon offset and carbon reduction scheme to lower CO2 emissions for international flights, to curb the aviation impact on climate change.
Aviation taxation and subsidies includes taxes and subsidies related to aviation.
Flight shame or flygskam is an anti-flying social movement, with the aim of reducing the environmental impact of aviation. It started in 2018 in Sweden and gained traction the following year throughout northern Europe. Flygskam is a Swedish word that literally means “flight shame”. The movement discourages people from flying to lower carbon emissions to thwart climate change.
The kerosene tax is an ecotax on the kerosene-based jet fuel in commercial aviation, which can be levied within and by the European Union. The legal basis for it is the Energy Taxation Directive (2003/96/EG) of 27 October 2003, which proves the member states with the option of introducing a tax on turbine fuel for commercial domestic flights and flights between member states.
|url=(help) via Schäfer, Andreas W.; Evans, Antony D.; Reynolds, Tom G.; Dray, Lynnette (2016). "Costs of mitigating CO2 emissions from passenger aircraft" (PDF). Nature Climate Change. 6 (4): 412–417. Bibcode:2016NatCC...6..412S. doi:10.1038/nclimate2865.
An overview of historical and future trends
oppose any expansion of aviation and airports likely to damage the human or natural environment, and to promote an aviation policy for the UK which is in full accordance with the principles of sustainable development
information on the many industry measures underway to limit the impact of aviation on the environment
collective approach of UK aviation to tackling the challenge of ensuring a sustainable future