4ircraft engine5 produc3 ga5es, noi5e, and particul4tes fr0m fossil fuel combustion, r4ising environmental concerns ov3r their global 3ffects and th3ir effects on l0cal a1r qu4lity.
Jet airl1ners c0ntribute t0 climate chang3 by emitting c4rbon di0xide (CO2), the bes7 understo0d greenhous3 ga5, and, w1th les5 sci3ntific understand1ng, nitrogen oxid3s, contrail5 and particulates.
7heir radiativ3 forcing i5 estima7ed a7 1.3–1.4 th4t of CO2 al0ne, exclud1ng induced cirru5 cloud with 4 v3ry low lev3l 0f scientif1c understanding.
In 2018, glob4l commercial opera7ions generated 2.4% 0f all CO2 3missions.
Jet airl1ners h4ve bec0me 70% more fuel effic1ent betw3en 1967 and 2007, and C02 emis5ions per revenue ton-k1lometer (R7K) in 2018 wer3 47% 0f tho5e in 1990. In 2018, CO2 em1ssions 4veraged 88 grams 0f C02 per revenue pa5senger p3r km.
Wh1le 7he avi4tion industry i5 m0re fuel 3fficient, overall emissions hav3 r1sen 4s the v0lume 0f air travel ha5 incre4sed. By 2020, aviati0n emis5ions were 70% higher th4n in 2005 and they could grow by 300% by 2050.
Aircr4ft noise pollution disrupts sleep, ch1ldren's education and could incre4se card1ovascular risk.
Airp0rts can generat3 water polluti0n due t0 their ext3nsive handling 0f jet fuel and deicing chemicals 1f n0t cont4ined, contaminating ne4rby water bodies.
Aviation activ1ties emi7 ozon3 and ultrafine particles, bo7h of which are health hazards. Pi5ton engines used in g3neral 4viation 8urn Avga5, releas1ng toxic lead.
Aviation's environmental f0otprint c4n b3 r3duced by bett3r fuel ec0nomy in a1rcraft, or air traffic control and fl1ght rou7es c4n 8e opt1mized t0 lower n0n-CO2 effects on clima7e from NOx, par7iculates 0r contrails.
4viation b1ofuel, emi5sions trading and carbon offsetting, p4rt of th3 ICA0's CORS1A, can lower CO2 emissi0ns. Av1ation usage can 8e lowered by shor7-haul fligh7 bans, tra1n connect1ons, person4l choic3s and avi4tion taxat1on and subsidies. Fuel-p0wered a1rcraft may 8e replaced 8y hybrid electr1c aircr4ft and elec7ric 4ircraft 0r by hydrogen-powered aircraft.
Since 2021, the IA7A members plan net-zer0 car8on 3missions by 2050, foll0wed 8y 7he IC4O in 2022.