Tsarin muhalli a cikin sufuri na jirgin kasa

Tsarin muhalli wani batu ne mai tasowa a cikin fasahar jirgin kasa. Daga shekarun 1980 zuwa 2009, ingancin man fetur a cikin locomotives na diesel a Amurka ya karu da kashi 85%,  yana ba da damar waɗannan jiragen su ci gaba da motsa ƙarin kaya yayin amfani da ƙananan man fetur. Sabbin jiragen kasa na lantarki da na matasan sun rage yawan hayakin carbon. Har ila yau, masana'antun jirgin ƙasa sun fara amfani da Fasahar hydrogen don motsawa, tare da fitar da carbon kawai daga masana'antar hydrogen kanta.

## Ƙara inganci yayin rage hayaki

Jiragen ƙasan Diesel sun maye gurbin injin tururi a ƙarshen 1920s a matsayin mafi tsaftar hanyar motsa mutane da kayayyaki.  Tun daga 1980, adadin kayan da jiragen Diesel ke jigilar su ya kusan ninki biyu, amma duk da haka yawan man da ake amfani da shi na jiragen kasa ya kusan zama iri ɗaya.[] Ƙididdiga sun nuna cewa kusan galan US biliyan 45 (170×10 ^ 6 m3) na mai an sami ceto ta hanyar haɓaka inganci a cikin jiragen dizal.  Ma'aikatar Makamashi ta Amurka ta ba da rahoton cewa ƙarfin makamashin jirgin sama na kasuwanci ya kasance raka'a na thermal na Biritaniya 3,587 a kowace mil (2,352 kJ/km), motoci sun kasance 3,549 thermal units na Biritaniya a kowace mil (2,327 kJ/km), yayin da ƙarfin makamashin jirgin ƙasa ya kasance kawai 2,751 na Biritaniya wanda ke nuna ma'aunin zafi na Biritaniya.  sufurin jirgin kasa shi ne ya fi karfin makamashi a cikin ukun.  Titin Union Pacific Rail Road ya aiwatar da tacewa barbashi akan injinan dizal ɗin su.  Silicon carbide yana toshe ɓangarorin tarko daga shaye-shaye yayin da suke barin injin, yana rage yawan hayaƙi.

### Jirgin ƙasa na lantarki
Jirgin lantarki koyaushe ba su da hayakin carbon kai tsaye saboda ana gudanar da su gaba ɗaya ta hanyar motocin lantarki na ciki. Koyaya, hanyar samar da wutar lantarki da aka yi amfani da ita don samar da wutar wutar lantarki ta fi dacewa da ƙone man fetur ko kwal, dukansu biyu suna samar da iskar carbon mai yawa. Tare da fitowar 'makamashi mai tsabta', jiragen lantarki a zahiri suna gudana tare da ƙananan tasirin muhalli. Misali, shawarar don layin dogo mai saurin gudu tsakanin San Francisco da Los Angeles a California yana da damar yin amfani da iskar gas mai guba, tare da 3,350 GWh a kowace shekara ana samar da shi ta hanyar manyan kayan aikin California na hanyoyin samar da makamashi.

### Jirgin kasa na Hybrid

Tun daga shekara ta 1986, injiniyoyi suna haɓaka jiragen ƙasa na lantarki-diesel "haɗe-haɗe". Ɗaya daga cikin nau'ikan jirgin ƙasa yana aiwatar da ƙarfin batir lokacin da jirgin ke aiki kuma a ƙananan motsi, da kuma injin diesel a mafi girman gudu. Don sake caji batir, ana amfani da wutar lantarki daga motar dizal, caji ta amfani da sake farfadowa, ko haɗuwa da duka biyun. A cewar Cibiyar Injiniyoyin Lantarki da Lantarki, jiragen kasa masu haɗari sun rage hayakin carbon na Diesel da kashi 19%. Wani nau'in jirgin kasa mai haɗari, kamar RailPower Technologies Green Goat, yana amfani da babban batir, da ƙaramin janareto ("genset") don wutar lantarki. Ana gudanar da genset a cikin saurin dindindin kuma an haɗa shi da janareta don sake cika batirin.

### Jirgin ruwa
Hydrogen propulsion fasaha ce mai tasowa, kuma a halin yanzu ana aiwatar da ita a cikin locomotives. Jiragen kasa masu amfani da hydrogen da ake kira "Hydrail" suna fitar da ruwa ne kawai a matsayin samfurin konewa, kuma suna da fitar da iskar gas kai tsaye. Koyaya, tsarin da aka yi amfani da shi don samar da hydrogen a cikin hanyar da ke da amfani ga jiragen ƙasa yana samar da ƙananan iskar gas. Ta hanyar amfani da makamashi na iska da lantarki, ana samar da gram 6.85 na iskar gas a kowace MJ na LHV, wanda ba shi da mahimmanci idan aka kwatanta da fam 22 na iskar iskar gas daga galan daya na man fetur. Jiragen ƙasa sune manyan manufofi don motsawar hydrogen saboda ikon su na adana manyan tankuna na hydrogen.&nbsp;

## Kwatancen hayaki
Jirgin ƙasa yana fitar da kusan fam 0.2 na iskar gas a kowane mil fasinja (fam 0.2 a mil (56 g/km)) lokacin da kowace mota ta cika da fasinjoji 50.  Wannan adadi yana ƙaruwa zuwa kusan fam 0.5 a kowane mil fasinja (140 g/km) lokacin da aka cika rabin adadin kawai.  Waɗannan lambobin har yanzu sun yi ƙasa da na jigilar jet, kusan fam 1 a kowane mil fasinja (280 g/km), da na direban motar solo, kusan fam 1.15 a kowane mil fasinja (325 g/km).  Hatta Prius mai ingantaccen mai yana fitar da iskar gas mai zafi a kowane mil fasinja.

Kimanin ya nuna cewa idan kawai kashi 10% na jigilar kaya mai nisa wanda a halin yanzu ke motsawa ta mota za a motsa shi a maimakon haka ta hanyar jiragen kasa na diesel, sakamakon raguwar fitar da carbon zai zama daidai da ɗaukar motoci miliyan 2 daga hanya. Sakamakon ya fi ban mamaki lokacin da aka maye gurbin adadi na jirgin kasa na diesel da adadi na jiragen kasa na lantarki.