Environmental effects of aviation

**1. Emissions and Climate Change Effects:**
– Aircraft engines emit gases, noise, and particulates from fossil fuel combustion.
– Jet airliners contribute to climate change by emitting carbon dioxide (CO₂) and nitrogen oxides.
– Global commercial operations generated 2.4% of all CO₂ emissions in 2018.
– CO₂ emissions per revenue ton-kilometer (RTK) in 2018 were 47% of those in 1990.
– Aviation emissions were 70% higher in 2020 than in 2005 and could grow by 300% by 2050.
– Aircraft emit gases (CO₂, water vapor, nitrogen oxides) and particulates.
– CO₂ emissions are the most significant greenhouse gas contribution.
– Nitrogen oxides favor ozone formation in the upper troposphere.
– Contrails and cirrus clouds contribute to global warming.
– Sulfate and soot particles from aviation have varying effects on climate.

**2. Health and Environmental Impact:**
– Aircraft noise pollution disrupts sleep, children’s education, and could increase cardiovascular risk.
– Aviation activities emit ozone and ultrafine particles, which are health hazards.
– Piston engines used in general aviation burn Avgas, releasing toxic lead.
– Airports can generate water pollution due to their handling of jet fuel and deicing chemicals.
– Aviation biofuel, emissions trading, and carbon offsetting can help lower CO₂ emissions.
– Air traffic disrupts sleep and adversely affects health.
– Aviation is the main human source of ozone, causing an estimated 6,800 premature deaths per year.
– Aircraft engines emit ultrafine particles (UFPs) in and near airports.
– 167,000 piston aircraft engines in the US burn Avgas, releasing lead into the air.
– EPA estimated 34,000 tons of lead were released into the atmosphere from 1970 to 2007.

**3. Air Traffic Volume and Efficiency:**
– By 2018, airline traffic reached 4.3 billion passengers with 37.8 million departures.
– The traffic growth rate was 4.3% annually, with an average of 114 passengers per flight.
– RPKs increased from 109 to 8,269 billion between 1960 and 2018.
– The aviation industry has become more fuel-efficient but overall emissions have risen due to increased air travel.
– Better fuel economy in aircraft and optimized air traffic control can lower emissions.
– Jet airliners became 70% more fuel efficient between 1967 and 2007.
– The average fuel burn of new aircraft fell 45% from 1968 to 2014.
– CO2 emissions per revenue ton-kilometer (RTK) were halved by 47% compared to 1990 by 2018.
– ICAO targets a 2% efficiency improvement per year between 2013 and 2050.

**4. Mitigation Strategies and Technological Innovation:**
– Aviation’s environmental footprint can be reduced by optimizing flight routes and capping emissions.
– ICAO committed to improving aviation fuel efficiency by 2% per year.
– Measures for mitigation include more fuel-efficient aircraft technology and sustainable aviation fuels.
– UK Climate Change Committee suggested demand management and use of sustainable aviation fuels.
– IATA and ICAO committed to net-zero carbon emissions by 2050.
– Development of electric aircraft can mitigate environmental damage.
– Biofuels and increased fuel efficiency are key innovations.
– Europes aviation sector aims for zero CO2 emissions by 2050.
– New short-haul engines and higher SAF production are part of decarbonizing aviation.
– Carbon offsets could be used if less expensive than SAFs.

**5. Water Pollution and Economic Measures:**
– Airports generate water pollution due to jet fuel and chemical handling.
– Deicing fluids used in cold weather can contaminate water bodies.
– Ethylene and propylene glycol in deicing fluids consume oxygen needed by aquatic life.
– Pavement deicers used at airports can contain harmful chemicals.
– Low oxygen concentrations in water due to deicing fluids can harm aquatic organisms.
– Increasing taxation and decreasing subsidies to the aviation industry can help reduce environmental impact.
– Market-based measures like emission trading and levies are effective.
– The aviation sector could be decarbonized by 2050 with moderate demand growth.
– Carbon offsets may be preferred if carbon credits are less expensive than SAFs.
– Fuel represents 20-30% of airlines’ operating costs, with SAF being more expensive.

Environmental effects of aviation (Wikipedia)

Aircraft engines produce gases, noise, and particulates from fossil fuel combustion, raising environmental concerns over their global effects and their effects on local air quality. Jet airliners contribute to climate change by emitting carbon dioxide (CO₂), 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 CO₂ alone, excluding induced cirrus cloud with a very low level of scientific understanding. In 2018, global commercial operations generated 2.4% of all CO₂ emissions.

Jet airliners have become 70% more fuel efficient between 1967 and 2007, and CO₂ emissions per revenue ton-kilometer (RTK) in 2018 were 47% of those in 1990. In 2018, CO₂ emissions averaged 88 grams of CO₂ 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 activities emit ozone and ultrafine particles, both of which are health hazards. Piston engines used in general aviation burn Avgas, releasing toxic lead.

Aviation's environmental footprint can be reduced by better fuel economy in aircraft, or air traffic control and flight routes can be optimized to lower non-CO₂ effects on climate from NO
_x, particulates or contrails. Aviation biofuel, emissions trading and carbon offsetting, part of the ICAO's CORSIA, can lower CO₂ 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. Since 2021, the IATA members plan net-zero carbon emissions by 2050, followed by the ICAO in 2022.