Methane na sararin samaniya

**[[methane]] na sararin samaniya** shine methane da ke cikin sararin samaniya. Adadin methane na yanayi yana ƙaruwa saboda hayakin methane, kuma yana haifar da Canjin yanayi. Methane yana daya daga cikin iskar gas mai karfi. : 82 Methane's radiative forcing (RF) na yanayi kai tsaye ne, : 2 kuma shine na biyu mafi girma mai ba da gudummawa ga tilasta yanayin da mutum ya haifar a cikin tarihin tarihi.  : 2 Methane babban tushen tururi ne na ruwa a cikin stratosphere ta hanyar oxidation;  kuma tururi na ruwa yana ƙara kusan 15% ga tasirin tilasta methane.  Halin dumama na duniya (GWP) don methane kusan 84 ne dangane da tasirinsa a cikin shekaru 20, da 28 dangane da tasirin sa a cikin shekaru 100.  

Tun farkon Juyin Juya Halin Masana'antu (kimanin 1750), yawan methane a cikin yanayi ya karu da kusan 160%, kuma ayyukan ɗan adam kusan gaba ɗaya sun haifar da wannan karuwa. Tun daga shekara ta 1750 methane ya ba da gudummawa ga kashi 3% na iskar gas (GHG) dangane da taro  amma yana da alhakin kusan kashi 23% na radiative ko tilasta yanayi.   A shekara ta 2019, yawan methane na duniya ya tashi daga sassa 722 a kowace biliyan (ppb) a lokacin da aka fara masana'antu zuwa 1866 ppb. Wannan karuwa ce ta hanyar kashi 2.6 kuma mafi girman darajar a cikin akalla shekaru 800,000. &nbsp;

## Matsayi a cikin canjin yanayi

Methane (CH 4 ) a cikin yanayin duniya shine iskar gas mai ƙarfi mai ƙarfi tare da yuwuwar dumamar yanayi (GWP) sau 84 fiye da CO 2 sama da shekaru 20.   Methane baya dagewa kamar CO 2, kuma wutsiya ya kashe kusan sau 28 fiye da CO 2 sama da tsawon shekaru 100. 

Radiative ko tilasta yanayi shine tunanin kimiyya da ake amfani dashi don auna tasirin ɗan adam akan muhalli a watts kowace murabba'in mita (W/m 2 ).  Yana nufin "bambanci tsakanin hasken rana da duniya ke sha da kuma makamashin da ke haskakawa zuwa sararin samaniya"  An kiyasta tasirin iskar gas mai raɗaɗi na kai tsaye na methane ya zama karuwa na 0.5 W / m 2 dangane da shekara ta 1750 (ƙididdigar 2007).  

A cikin rahoton su na 2021 "Global Methane Assessment", UNEP da CCAC sun ce "maganin tasirin methane akan tilasta radiative" ya inganta tare da bincike ta ƙungiyoyin da M. Etminan ke jagoranta a cikin 2016,  da William Collins a cikin 2018.  Wannan ya haifar da "binciken sama" tun daga rahoton kimantawa na biyar na IPCC na 2014 (AR5). "Ingantaccen fahimta" ya ce ƙididdigar da ta gabata game da "dukan tasirin al'umma na hayakin methane" mai yiwuwa an rage su

Etminan et al. sun buga sabon lissafin su don methane's radiative tilastawa (RF) a cikin wani labarin na 2016 Geophysical Research Letters journal wanda ya haɗa gajerun igiyoyin gajerun igiyoyin CH 4 wajen auna tilas, ba a yi amfani da su a baya, hanyoyin IPCC mafi sauƙi ba. Sabbin lissafin su na RF wanda ya sake yin bitar waɗanda aka ambata a baya, rahotannin IPCC na gaba don tilastawa gaurayewar iskar gas (WMGHG) ta hanyar haɗa abubuwan tilasta gajerun igiyoyin ruwa saboda CH 4, ya haifar da ƙididdiga waɗanda ke kusan 20-25% mafi girma.  Collins et al. ya ce rage karfin CH 4 da ke rage methane na yanayi a karshen karni, zai iya "samu gagarumin bambanci ga yuwuwar cimma manufofin yanayi na Paris", kuma zai samar mana da karin "halayen iskar carbon da aka yarda da shi zuwa 2100". 

## Manazarta