Ikon ɗaukar kaya

Capacity na ɗaukar yanayi shine matsakaicin girman yawan jinsunan halittu wanda za'a iya kiyaye shi ta wannan takamaiman yanayi, idan aka ba da abinci, mazauni, ruwa, da sauran albarkatun da ke akwai. An bayyana ƙarfin ɗaukar kaya a matsayin mafi girman nauyin muhalli, wanda a cikin yanayin muhalli ya dace da daidaitattun yawan jama'a, lokacin da yawan mutuwar a cikin yawan jama'ar yayi daidai da yawan haihuwa (kazalika da shige da fice da ƙaura). Gudanar da ƙarfin muhalli yana nuna cewa fitar da albarkatun ba sama da yawan sake farfaɗo da albarkatuna ba kuma sharar da aka samar tana cikin ikon dai-daita yanayin. Tasirin ƙarfin ɗaukar nauyi akan Yawan jama'a ana tsara shi tare da aikin dabaru. Ana amfani da ƙarfin ɗaukar kaya ga matsakaicin yawan jama'a da mahalli zai iya tallafawa a cikin muhalli, noma da kamun kifi. Anyi amfani da kalmar ɗaukar nauyi ga wasu matakai daban-daban a baya kafin a ƙarshe ayi amfani da ita ga iyakokin yawan jama'a a cikin shekarun 1950. Ma'anar iya ɗaukar mutane an rufe shi da ra'ayin yawan jama'a mai ɗorewa.

An buga cikakken bincike na farko game da iyakokin duniya a cikin littafin 1972 Limits to Growth, wanda ya haifar da sharhin da bincike, gami da zargi da yawa. Wani bita na shekara ta 2012 a cikin Nature da masu bincike na kasa da kasa 22 suka nuna damuwa cewa Duniya na iya "kusanci canjin yanayi" wanda biosphere na iya zama mara karɓar baƙi ga rayuwar ɗan adam kuma wanda ƙarfin ɗaukar ɗan adam na iya raguwa. Wannan damuwa cewa bil'adama na iya wucewa fiye da "maɓallin kai tsaye" don amfani da biosphere mai aminci yakaru a cikin shekaru masu zuwa. Kimanin kwanan nan na ƙarfin ɗaukar duniya yana gudana tsakanin mutane biliyan biyu zuwa biliyan huɗu, dangane da yadda masu bincike masu kyakkyawan fata suke game da hadin gwiwar kasa da kasa don magance matsalolin aiki tare.

## Asalin
Dangane da Yawan jama'a, kalmar 'ƙwarewar ɗaukar' ba'ayi amfani da ita a bayyane a cikin 1838 ta hanyar masanin lissafi na Belgian Pierre François Verhulst lokacin da yafara buga lissafinsa bisa ga bincike kan ƙirar ƙimar yawan jama'ar.

Asalin kalmar "ƙwarewar ɗaukar" ba ta da tabbas, tare da tushe daban-daban da ke nuna cewa anyi amfani dashi da farko "a cikin mahallin jigilar kayayyaki na duniya" a cikin shekarun 1840,   ko kuma an fara amfani dashi a lokacin gwaje-gwaje na dakin gwaje-gidan gwaje-gaje na ƙarni na 19 tare da micro-organisms.  Binciken 2008 ya gano amfani da kalmar a Turanci shine rahoton 1845 na Sakataren Harkokin Wajen Amurka ga Majalisar Dattijan Amurka. Daga nan sai ya zama kalmar da akayi amfani da ita gabaɗaya a cikin ilmin halitta a cikin shekarun 1870, kasancewar ya fi bunkasa a cikin namun daji da kula da dabbobi a farkon shekarun 1900. Ya zama kalma mai mahimmanci a cikin ilimin muhalli da akayi amfani dashi don bayyana iyakokin halittu na tsarin halitta dake da alaƙa da girman yawan jama'a a cikin shekarun 1950.

Neo-Malthusians da eugenicists sun shahara da amfani da kalmomin don bayyana yawan mutanen da Duniya zats iya tallafawa a cikin shekarun 1950,  kodayake masana kimiyyar halittu na Amurka Raymond Pearl da Lowell Reed sun riga sun yi amfani dashi a cikin waɗannan kalmomin ga yawan mutane a cikin shekarun 1920. 

Hadwen da Palmer (1923) sun bayyana ikon ɗaukar kaya a matsayin yawan kayan da za'a iya kiwo na wani lokaci batare da lalacewar kewayon ba.

An fara amfani da shi a cikin mahallin kula da namun daji ta Amurka Aldo Leopold a 1933, kuma bayan shekara guda daga Amurka Paul Lester Errington, ƙwararren masanin ruwa. Sunyi amfani da kalmar a hanyoyi daban-daban, Leopold galibi a ma'anar dabbobi masu kiwo (banbanci tsakanin 'matakin cikawa', matakin ƙididdigar jinsin da zasu rayu a ciki, da ɗaukar damar, mafi yawan dabbobi waɗanda zasu iya kasancewa a fagen) da kuma Errington yana bayyana 'ƙwarewar ɗaukar' kamar yawan dabbobi sama da abin da farauta zai zama 'mai nauyi' (wannan ma'anar an ƙi shi sosai, gami da Errington da kansa). Muhimmin kuma sanannen littafi na 1953 game da ilimin muhalli na Eugene Odum, Fundamentals of Ecology, ya shahara da kalmar a cikin ma'anar zamani a matsayin ma'auni na ma'aunin ma'aikatar tsarin haɓaka yawan jama'a.  

## Lissafi
Takamaiman dalilin da yasa yawan jama'a ya daina girma an san shi da iyakancewa ko daidaitawa.

Bambanci tsakanin yawan haihuwa da yawan mace-mace shine karuwar halitta. Idan yawan mutanen da aka ba su yana ƙasa da ƙarfin ɗaukar wani yanayi, wannan yanayin na iya tallafawa ƙaruwa mai kyau; idan ya sami kansa sama da wannan ƙofar yawan jama'a yawanci yana raguwa. Don haka, ƙarfin ɗaukar hoto shine matsakaicin adadin mutane na jinsin da mahalli zai iya tallafawa a cikin dogon lokaci.

Yawan jama'a yana raguwa sama da ƙarfin ɗaukar kaya saboda dalilai da yawa dangane da nau'in da aka shafa, amma yana iya haɗawa da isasshen sarari, samar da Abinci, ko Hasken rana. Ikon ɗaukar yanayi ya bambanta ga nau'o'i daban-daban.

A ci**K** algebra na muhalli kamar yadda aka kwatanta a cikin tsarin Verhulst mai sauƙi na Yawan jama'a, ƙarfin ɗaukar kaya yana wakiltar K mai ɗorewa:

:  \frac{dN}{dt} = rN \left(1 - \frac{N}{K}\right) 

inda

* N shine yawan jama'a,
* r shine ƙimar haɓaka ta ainihiGirman ci gaba
* K shine ƙarfin ɗaukar mahalli na gida, kuma
* 

Jamusanci *Kapazitätsgrenze* (ƙayyadadden iyawa).

Wannan daidaitattun gyare-gyare ne na asalin Verhulst model:

:  \frac{dN}{dt} = rN - \alpha N^2

A ciK wannan daidaitattun, ƙarfin ɗaukar kaya K, 

N 

Sanya 

{\displaystyle N^{*}} 

, shine

:  N^* = \frac{r}{\alpha}. 

LoK da aka tsara samfurin Verhulst a cikin jadawalin, canjin yawan jama'a a tsawon lokaci yana ɗaukar nau'in sigmoid, yana kaiwa matakin mafi girma a K. Wannan shine tsarin ci gaban dabaru kuma an lissafa shi tare da:

: f(x) = \frac{L}{1 + e^{-k(x-x_0)}},

inda

* e shine tushen logarithm na halitta (wanda aka fi sani da lambar Euler),
* x" data-mw="{"parts":[{"template":{"target":{"wt":"math","href":"./Template:Math"},"params":{"1":{"wt":"x"}},"i":0}}]}" data-ve-no-generated-contents="true" id="mwuQ" typeof="mw:Transclusion">*x*0 shine darajar x na tsakiyar sigmoid,
* L shine matsakaicin darajar layin,
* K shine ƙimar haɓaka ko tsayi na layin  da
* f(x_0) = L/2.

Tsarin cigaban dabaru yana nuna yadda yawan cigaban jama'a da ƙarfin ɗaukar kaya ke haɗuwa. Kamar yadda aka kwatanta a cikin tsarin tsarin cigaban tsari, lokacin da yawan jama'a yayi ƙanƙanta, yawan jama'ar yana ƙaruwa sosai. K, yayin da yawan jama'a ke kusa da ƙarfin ɗaukar nauyi, ci gaban yana raguwa kuma ya kai sifili a K.

Abin dake ƙayyade ƙwarewar ɗaukar takamaiman tsarin ya haɗa da iyakancewar; wannan na iya samun wadataccen abinci ko ruwa, wuraren nesting, sarari, ko adadin sharar gida za'a iya sha batare da lalata muhalli ba kuma rage ƙarfin ɗaukar kaya.

## Ilimin muhalli na yawan jama'a
Capacity na ɗaukar hoto shine ra'ayi da aka saba amfani dashi ga masu ilimin halitta yayin ƙoƙarin fahimtar yawan halittu da abubuwan dake shafar su. Lokacin da ake magana da yawan halittu, ana iya ganin ƙarfin ɗaukar nauyi a matsayin daidaitattun daidaito, tare da la'akari da ƙarancin lalacewa da ƙimar mulkin mallaka. A cikin ilmin halitta na yawan jama'a, ci gaban dabaru yana ɗauka cewa yawan jama'ar yana canzawa sama da ƙasa da ƙimar daidaitawa.

Marubutan da yawa sunyi tambaya game da amfanin kalmar lokacin da aka yi amfani da ita ga ainihin mutanen daji. Kodayake yana da amfani a cikin ka'idar da gwaje-gwaje na dakin gwaje-gaje, ɗaukar damar a matsayin hanyar auna iyakokin yawan jama'a a cikin muhalli bashi da amfani kamar yadda wani lokacin yakan sauƙaƙa hulɗar tsakanin jinsuna.

## Aikin noma
Yana da mahimmanci ga manoma su lissafa ƙarfin ɗaukar ƙasarsu don su iya kafa ƙimar ɗorewa mai ɗorewa. Misali, lissafin ƙarfin ɗaukar kaya a Ostiraliya ana yin sa a Dry Sheep Equivalents (DSEs). DSE guda ɗaya shine 50 kg Merino wether, busassun ƙwai ko mara ciki, wanda aka kiyaye shi a cikin yanayi mai ɗorewa. &nbsp;Ba wai kawai ana lissafin tumaki a cikin DSEs ba, ana lissafin ƙarfin ɗaukar wasu dabbobi ta amfani da wannan ma'auni. Ɗan maraƙi mai nauyin kilo 200 na salon Burtaniya wanda ke samun 0.25 kg / rana shine 5.5DSE, amma idan nauyin wannan nau'in maraƙi yana samun 0.75 kg / rana, za a auna shi a 8DSE. &nbsp;&nbsp;&nbsp;Karnuka ba iri ɗaya ba ne, DSEs ɗin su na iya bambanta dangane da jinsi, ƙimar girma, nauyi, idan saniya ce ('dam'), shanu ko bijimi ('bullock' a Ostiraliya), kuma idan yana yayewa, ciki ko 'ruwa' (watau shayarwa).

A wasu sassan duniya ana amfani da raka'a daban-daban don lissafin ƙarfin ɗaukar kaya. A cikin Ƙasar Ingila ana auna paddock a cikin LU, rukunin dabbobi, kodayake akwai tsare-tsare daban-daban don wannan. New Zealand tana amfani da ko dai LU,  EE (mafi dacewa) ko SU (rukunin ajiya).  A Amurka da Kanada tsarin gargajiya yana amfani da raka'a na dabbobi (AU).  Ƙungiyar Faransanci / Switzerland ita ce Unité de Gros Bétail (UGB).  

A wasu ƙasashen Turai kamar Switzerland ana auna makiyaya a al'ada a *Stoß*, tare da *Stoß* ɗaya daidai da Füße huɗu (ƙafafu). Tsarin Turai na zamani shine ''Großvieheinheit'' (GV ko GVE), wanda yadace da 500 kg a cikin nauyin shanu. &nbsp;A cikin aikin noma mai yawa 2 GV / ha shine yawan kayan aiki na yau da kullun, a cikin aikin gona, lokacin da aka kara makiyaya da ƙarin abinci, farashin na iya zama 5 zuwa 10 GV / hectare. A cikin Turai matsakaicin yawan kaya ya bambanta dangane da ƙasar, a cikin 2000 Netherlands da Belgium suna da babban adadin 3.82 GV / ha da 3.19 GV / hectare bi da bi, ƙasashen dake kewaye dasu  suna da ƙimar kusan 1 zuwa 1.5 GV / hektare, kuma ƙasashen kudancin Turai suna da ƙarancin ƙimar, tare da Spain da mafi ƙarancin 0.44 GV / hekta.

Hakanan ana iya amfani da wannan tsarin ga wuraren halitta. Kiwon Megaherbivores a kusan 1 GV / ha ana ɗaukarsa mai ɗorewa a cikin tsakiya na Turai, kodayake wannan ya bambanta sosai dangane da dalilai da yawa. A cikin ilimin muhalli yana da ka'ida (watau maye gurbin cyclic, patch dynamics, *Megaherbivorenhypothese*) an ɗauka cewa matsin kiwo na 0.3 GV / ha ta hanyar namun daji ya isa ya hana gandun daji a cikin yanki na halitta. Saboda nau'o'i daban-daban suna da wurare daban-daban na muhalli, tare da dawakai misali suna kiwon gajeren ciyawa, shanu masu tsayi, da awaki ko dabbobi da suka fi son bincika shrubs, bambancin niche yana bada damar ƙasa don samun ɗan ƙarfin ɗaukar hoto don ƙungiyar jinsuna, fiye da yadda zai kasance idan akwai nau'in jinsuna ɗaya kawai. 

Wasu tsare-tsaren kasuwar niche suna ba da umarnin ƙananan ƙididdigar kaya fiye da yadda za'a iya kiwo a kan makiyaya. Don tallata kayayyakin nama na mutum a matsayin 'biodynamic', an ba da umarnin ƙananan *Großvieheinheit* na 1 zuwa 1.5 (2.0) GV / ha, tare da wasu gonaki dake da tsarin aiki ta amfani da 0.5 zuwa 0.8 GV /ha kawai.

Kungiyar Abinci da Aikin Gona ta gabatar da raka'a uku na kasa da kasa don auna ƙarfin ɗaukar kaya: Ƙungiyoyin Dabbobi na FAO don Arewacin Amurka,  Ƙungiyoyin dabbobi na FAO na Afirka ta kudu da Sahara,  da Ƙungiyoyin Kula da Dabbobi na Tropical.

Wata hanya mai wuya kuma ba daidai ba ce ta tantance ƙarfin ɗaukar kaya na paddock shine kawai ta hanyar kallon yanayin garken. A Ostiraliya, tsarin daidaitaccen ƙasa don kimanta yanayin dabbobi ana yin sa ne ta hanyar ƙididdigar yanayin jiki (BCS). Ana samun dabba da ke cikin mummunan yanayi tare da BCS na 0, kuma dabba wacce keda matukar lafiya ana samun sa a 5: ana iya samun sa dabbobi tsakanin waɗannan lambobi biyu a cikin karuwar 0.25. Akalla dabbobi 25 na iri ɗaya dole ne a zira kwallaye don samar da lambar wakilci ta ƙididdiga, kuma dole ne a ci kwallaye kowane wata - idan matsakaicin ya faɗi, wannan na iya zama saboda yawan ajiya sama da ƙarfin ɗaukar paddock ko ƙananan abinci. Wannan hanyar bata kai tsaye ba don ƙayyade ƙimar ajiya fiye da kallon makiyaya da kansa, saboda canje-canje a cikin yanayin ajiya na iya komawa bayan canje-canje cikin yanayin makiyaya.

## Kifi

A cikin kamun kifi, ana amfani da ƙarfin ɗaukar kaya a cikin tsari don lissafin amfanin gona mai ɗorewa don Gudanar da kamun kifi. matsakaicin amfanin gona mai ɗorewa (MSY) an bayyana shi a matsayin "mafi girman matsakaicin kamawa wanda za'a iya ci gaba da ɗauka daga yawan mutanen da akayi amfani da su (= ajiya) a ƙarƙashin matsakaicin yanayin muhalli". MSY da farko an lissafa shi azaman rabin ƙarfin ɗaukar kaya, amma an inganta shi tsawon shekaru,  yanzu ana ganin kusan kashi 30% na yawan jama'a, dangane da jinsin ko yawan jama'ar.  Saboda yawan jinsin da aka kawo ƙasa da ƙarfin ɗaukarsa saboda kamun kifi zai sami kansa a cikin matakin haɓaka, kamar yadda aka gani a cikin samfurin Verhulst, girbi na yawan kifi a ko ƙasa da MSY shine amfanin da za'a iya girbe shi ba tare da rage yawan jama'a a daidaito ba, kiyaye yawan jama'ar a matsakaicin ɗaukar sa. *K*, ana iya ganin kamun kifi na sheka*r*-shekara a matsayin gyare-gyare na r a cikin daidaitattun -watau an canza yanayin, wanda ke nufin cewa girman yawan jama'a a daidaituwa tare da kamun kifin shekara-sheko yana da ɗan ƙasa da abin da K zai kasance ba tare dashi ba.

Lura cewa a lissafi da kuma a cikin sharuddan aiki, MSY yana da matsala. Idan aka yi kuskure harma da ƙananan kifi ana girbe su a kowace shekara sama da MSY, yawan jama'a yana nuna cewa yawan jama'ar zai ragu zuwa sifili. Ainihin ikon ɗaukar muhalli na iya canzawa a cikin ainihin duniya, wanda ke nufin cewa a zahiri, MSY na iya bambanta daga shekara zuwa shekara   (amfanin gona mai ɗorewa na shekara-shekara da matsakaicin matsakaicin ƙoƙarin ɗaukar wannan cikin la'akari).  Sauran irin waɗannan ra'ayoyin sune mafi kyawun amfanin gona mai ɗorewa da matsakaicin amfanin gona na tattalin arziki; waɗannan duka duka duka yawan girbi ne a ƙasa da MSY.  

Ana amfani da waɗannan lissafi don ƙayyade ƙididdigar kamun kifi.  

## Mutane
Ikon ɗaukar mutum aiki ne na yadda mutane ke rayuwa da kuma fasahar da suke da ita. Babban juyin juya halin tattalin arziki guda biyu da suka nuna tarihin ɗan adam har zuwa 1900 - juyin juya hali na noma da masana'antu - sun kara karfin ikon ɗaukar ɗan adam na duniya, suna bada damar yawan ɗan adam ya girma daga mutane miliyan 5 zuwa 10 a cikin 10,000 KZ zuwa biliyan 1.5 a cikin 1900. Babban cigaban fasaha na shekaru 100 da suka gabata - a cikin ilmin sunadarai, kimiyyar lissafi, kwamfuta, injiniyan kwayar halitta, da sauransu - sun kara karuwar ikon ɗaukar mutum na Duniya, aƙalla a cikin ɗan gajeren lokaci. Batare da tsarin Haber-Bosch don gyara nitrogen ba, aikin gona na zamani ba zai iya tallafawa mutane biliyan 8 ba. Batare da Green Revolution na shekarun 1950 da 60 ba, yunwa na iya kashe mutane da yawa a cikin ƙasashe masu talauci a cikin shekaru talatin da suka gabata na karni na ashirin.

Nasarorin fasaha na baya-bayan nan, duk da haka, sun zo da tsada mai tsanani na muhalli. Canjin yanayi, yaduwar teku, da manyan wuraren da suka mutu a bakin manyan koguna da yawa na duniya, aiki ne na sikelin aikin gona na zamani  da sauran bukatun da mutane biliyan 8 keyi a duniya.  Masana kimiyya yanzu suna magana game da bil'adama dake wucewa ko barazanar wucewa da iyakokin duniya 9 don amfanin biosphere. Tasirin muhalli na bil'adama da ba'a  taɓa gani ba yana barazanar lalata ayyukan muhalli waɗanda mutane da sauran rayuwa suka dogara da su - mai yuwuwar rage ikon ɗaukar ɗan adam na Duniya. Alamun cewa mun ƙetare wannan ƙofar suna ƙaruwa.  

The fact that degrading Earth's essential services is obviously possible, and happening in some cases, suggests that 8 billion people may be above Earth's human carrying capacity. But human carrying capacity is always a function of a certain number of people living a certain way. This was encapsulated by Paul Ehrlich and James Holdren's (1972) IPAT equation: environmental impact (I) = population (P) x affluence (A) x the technologies used to accommodate human demands (T). IPAT has found spectacular confirmation in recent decades within climate science, where the Kaya identity for explaining changes in  emissions is essentially IPAT with two technology factors broken out for ease of use.

Wannan yana nuna wa masu sa zuciya na fasaha cewa sabbin abubuwan da aka gano na fasaha (ko tura wadanda ke akwai) na iya cigaba da kara karfin ɗaukar mutum na Duniya, kamar yadda ya kasance a baya. Duk da haka fasahar tana da sakamako masu illa ba zato ba tsammani, kamar yadda muka gani tare da raguwar ozone na stratospheric, yawan nitrogen a cikin koguna da bays na duniya, da canjin yanayi na duniya. Wannan yana nuna cewa mutane biliyan 8 na iya zama masu dorewa na 'yan ƙarni, amma ba'a cikin dogon lokaci ba, kuma kalmar 'ƙwarewar ɗaukar' tana nuna yawan jama'a wanda ke dorewa har abada. Hakanan yana yiwuwa, cewa ƙoƙarin yin tsammanin da sarrafa tasirin sabbin fasahohi masu ƙarfi, ko raba ƙoƙarin da ake buƙata don ci gaba da tasirin muhalli na duniya a cikin iyakoki masu ɗorewa tsakanin kasashe sama da 200 duk suna bin bukatun kansu, na iya zama da rikitarwa don cimma su a tsawon lokaci.

Ɗaya daga cikin batutuwan dake tattare da yin amfani da ƙarfin ɗaukar hoto ga kowane nau'in shine cewa yanayin halittu ba koyaushe bane kuma yana canzawa a tsawon lokaci, saboda haka canza albarkatun dake akwai. Bincike ya nuna cewa wani lokacin kasancewar yawan mutane na iya kara yawan halittu na gida, yana nuna cewa mazaunin ɗan adam ba koyaushe yana haifar da sare daji da rage yawan halittu ba. Wani batun da za a yi la'akari da shi lokacin da ake amfani da ƙarfin ɗaukar kaya, musamman ga mutane, shine cewa auna albarkatun abinci ba bisa ka'ida ba ne. Wannan ya faru ne saboda zabar abin da za'ayi la'akari dashi (misali, ko a haɗa da tsire-tsire waɗanda ba'a samu a kowace shekara ba), yadda za a rarraba abin da ake la'akari (misali., rarraba tsire-shire masu cin abinci waɗanda ba a yawan cin su a matsayin albarkatun abinci ko a'a), da kuma ƙayyade idan ƙimar caloric ko ƙimar abinci mai gina jiki suna da dama. Ƙarin yadudduka ga wannan ga mutane sune bambance-bambance na al'adunsu a dandano (misali, wasu suna cinye ƙwayoyin da ke tashi) da kuma zaɓin mutum akan abin da za su saka hannun jari a cikin aikinsu (misali., kamun kifi vs. noma), dukansu sun bambanta a tsawon lokaci. Wannan yana haifar da buƙatar tantance ko a haɗa duk albarkatun abinci ko kawai waɗanda jama'ar da ake la'akari da su zasu cinye su. Gudanar da ma'aunin iyawa a kan manyan yankuna kuma yana ɗaukar daidaito a cikin albarkatun da ake dasu amma wannan ba ya lissafin yadda albarkatun kuma samun damar zuwa gare su zai iya bambanta sosai a cikin yankuna da yawan jama'a. Sun kuma ɗauka cewa yawan jama'a a yankin kawai sun dogara da albarkatun yankin duk da cewa mutane suna musayar albarkatu tare da wasu daga wasu yankuna kuma akwai kaɗan, idan akwai, yawan jama'ar da aka ware. Bambance-bambance a cikin yanayin rayuwa wanda ke tasiri kai tsaye a amfani da albarkatun ba'a la'akari dasu ba. Wadannan batutuwan sun nuna cewa yayin da akwai iyakoki ga albarkatun, ana buƙatar amfani da tsarin da yafi rikitarwa game da yadda mutane ke hulɗa da yanayin halittu don fahimtar su.

## Gargadi na baya-bayan nan cewa bil'adama na iya wuce ƙarfin ɗaukar ƙasa
Tsakanin 1900 da 2020, yawan mutanen duniya yakaru daga biliyan 1.6 zuwa biliyan 7.8 (karin 390%).  Wadannan nasarorin sun kara yawan bukatun albarkatun mutane, suna haifar da mummunar lalacewar muhalli.

### Binciken tsarin halittu na Millennium
Millennium Ecosystem Assessment (MEA) na shekara ta 2005 babban yunkuri ne na hadin gwiwa don tantance yanayin yanayin yanayin halittu na Duniya, wanda ya shafi masana sama da 1,300 a duk duniya. Abubuwa biyu na farko daga cikin manyan binciken da suka samu sune: Binciken farko shine:A cikin shekaru 50 da suka gabata, mutane sun canza yanayin halittu da sauri da yawa fiye da kowane lokaci mai kama dashi a tarihin ɗan adam, galibi don biyan buƙatun dake ƙaruwa da sauri don abinci, ruwa mai laushi, katako, fiber, da man fetur. Wannan ya haifar da asarar da baza'a iya juyawa ba'a cikin bambancin rayuwa a Duniya.Na biyu daga cikin manyan binciken guda huɗu shine:Canje-canjen da akayi wa yanayin halittu sun bada gudummawa ga samun riba mai yawa a cikin jin daɗin ɗan adam da cigaban tattalin arziki, amma an sami waɗannan nasarorin ne a farashin dake ƙaruwa ta hanyar lalacewar ayyukan yanayin halittu da yawa, ƙara haɗarin canje-canje marasa layi, da ƙaruwar talauci ga wasu kungiyoyin mutane. Wadannan matsalolin, sai dai idan an magance su, zasu rage fa'idodin da tsararraki masu zuwa ke samu daga yanayin halittu.A cewar MEA, waɗannan canje-canjen muhalli da ba'a taɓa gani ba suna barazanar rage ikon ɗaukar ɗan adam na dogon lokaci na Duniya. "Rashin lalacewar ayyukan yanayin halittu na iya zama mafi muni a farkon rabin wannan [21st] karni, "sun rubuta, yana aiki a matsayin shingen inganta rayuwar matalauta a duniya.

### Masu sukar Capacity tare da Dangantaka da Mutane
Mutane da al'adun ɗan adam da kansu abubuwa ne masu sauƙin daidaitawa waɗanda suka shawo kan batutuwan da suka zama kamar ba'a fahimta ba a lokacin da ya gabata. Ba'a ce iya ɗaukar nauyi ba wani abu ne daya kamata ayi la'akari dashi ba, amma ya kamata a ɗauka tare da wasu shakku lokacin da aka gabatar dashi a matsayin tabbacin tabbatar da wani abu. Yawancin masana kimiyyar halittu, masu ilimin muhalli, da masana kimiyyyar zamantakewa sun zubar da kalmar gaba ɗaya saboda ƙaddamar da akayi wanda ya haskaka kan rikitarwa na hulɗar dake faruwa a matakin micro da macro. Gudanar da iyawa a cikin yanayin ɗan adam yana ƙarƙashin canji a kowane lokaci saboda yanayin daidaitawa sosai na al'umma da al'adu. Idan an sanya albarkatun, lokaci, da makamashi a cikin matsala, akwai mafita dake fallasa kanta. Hakanan bai kamata a yi amfani da wannan a matsayin uzuri don cinyewa ko amfani da ƙasar ko albarkatun da ke akwai ba. Duk da haka, yana yiwuwa ba za a iya yin mummunan ra'ayi ba kamar yadda za'a iya hanzarta sauye-sauyen fasaha, zamantakewa, da kuma ma'aikata, musamman a lokacin bukata, don magance matsaloli, ko a wannan yanayin, kara karfin ɗaukar kaya. Har ila yau, akwai albarkatun da ke kan wannan Duniya waɗanda ke da iyaka waɗanda tabbas za su ƙare idan aka kula da su ko akayi amfani dasu batare da kulawa da ma'auni ba. Idan an bar abubuwa batare da an bincika su ba to ana iya amfani dayawa da kuma amfani da ƙasa da albarkatu.

### Lissafin sawun muhalli
Lissafin lissafin muhalli yana auna bukatun da mutane ke yi akan yanayi kuma yana kwatanta su da kayan da ake da su, ga ƙasashe da duniya gaba ɗaya. Mathis Wackernagel da William Rees ne suka kirkireshi, an gyara shi kuma an yi amfani dashi a wurare daban-daban a cikin shekaru ta hanyar Global Footprint Network (GFN). A gefen buƙata, sawun Muhalli yana auna yadda saurin yawan jama'a ke amfani da albarkatu da kuma samar da sharar gida, tare da mai da hankali kan manyan wurare biyar: amfani da makamashi, ƙasa da aka sadaukar don daidaitawa kai tsaye, amfani da katako da takarda, amfani da abinci da fiber, da amfani da abincin teku. Yana canza waɗannan zuwa kowane mutum ko jimlar hekta da akayi amfani dasu. A bangaren samarwa, ƙwarewar halittu ta ƙasa ko ta duniya tana wakiltar yawan kayan muhalli a cikin wata al'umma ko duniya gaba ɗaya; wannan ya haɗa da "ƙasa, filayen kiwo, filayen daji, filayen kamun kifi, da ƙasar da aka gina. "  Har ila yau ana fassara ma'auni daban-daban don kama ƙwarewar rayuwa a cikin lokaci ɗaya na hekta na ƙasar da ke akwai. Kamar yadda Cibiyar Nazarin Duniya (GFN) ta bayyana:Kowace birni, jiha ko ƙasa za'a iya kwatanta sawun muhalli da ƙarfinsa, ko na duniya. Idan sawun muhalli na yawan jama'a ya wuce ikon halittu na yankin, wannan yankin yana da karancin ikon halittu. Bukatarsa ga kayayyaki da aiyuka da ƙasarsa da tekun zasu iya samarwa - 'ya'yan itatuwa da kayan lambu, nama, kifi, itace, auduga don tufafi, da kuma shan carbon dioxide - ya wuce abin da yanayin yankin zai iya sabuntawa. A cikin shahararrun sadarwa, muna kuma kiran wannan "rashin muhalli". Yankin da ke cikin rashi na muhalli yana biyan buƙata ta hanyar shigowa, kawar da kadarorinsa na muhallar (kamar yawan kamun kifi), da / ko fitar da carbon dioxide a cikin yanayi. Idan ikon halittu na yanki ya wuce sawun muhalli, yana da ajiyar ikon halittu.Dangane da lissafin GFN, bil'adama suna amfani da albarkatu da samar da sharar gida fiye da dorewa tun kusan 1970: a halin yanzu muna amfani da albarkatun Duniya a kusan 160% na iyawa. Wannan yana nuna cewa bil'adama yafi ƙarfin ɗaukar ɗan adam na Duniya don matakanmu na yanzu na wadata da amfani da fasaha. A cewar GFN:A cikin 2022, Ranar Duniya ta fadi a ranar 28 ga Yuli. Ranar Duniya ta nuna ranar da bil'adama ta gaji da kasafin kudin yanayi na shekara. A sauran shekara, muna kula da rashi na muhalli ta hanyar janye kayan aiki na gida da tara carbon dioxide a cikin yanayi. Muna aiki a cikin overshoot.Ana iya ganin manufar 'overhoot' daidai da wuce ikon ɗaukar ɗan adam. Dangane da lissafin kwanan nan daga GFN, yawancin mazaunan duniya suna zaune a cikin ƙasashe masu yawa na muhalli (duba taswirar da ke dama). 

Wannan ya haɗa da ƙasashe masu yawan jama'a (kamar China, Indiya, da Philippines), ƙasashe masu amfani da yawa da amfani da albarkatu (Faransa, Jamus, da Saudi Arabia), da ƙasashe dake da yawan amfani da yawa (Japan, Ingila, da Amurka). 

### Tsarin iyakokin duniya
A cewar masu haɓakawa, tsarin iyakokin duniya ya bayyana "sararin aiki mai aminci ga bil'adama bisa ga tsarin halittu na ciki wanda ke tsara kwanciyar hankali na tsarin Duniya. "  wayewar ɗan adam ta samo asali ne a cikin kwanciyar hankali ga zamanin Holocene; ƙetare iyakokin duniya don matakan tsaro na carbon na yanayi, acidity na teku, ko ɗaya daga cikin sauran iyakokin da aka bayyana na iya aika da tsarin halittu ya shiga cikin sababbin yanayi waɗanda basu da kyau ga rayuwa - mai yiwuwa rage ƙarfin ɗaukar ɗan adam na duniya. Wannan tsarin, wanda aka haɓaka a cikin wata kasida da aka buga a cikin Nature  sannan aka sabunta shi a cikin labaran biyu da aka buga A cikin 2015 a cikin *Kimiyya* [1] kuma a cikin 2018 a cikin *PNAS*,  ya gano masu damuwa tara na tsarin tallafin duniya waɗanda ke buƙatar kasancewa a cikin iyakoki masu mahimmanci don adana yanayin biospheric mai ɗorewa da aminci (duba adadi da ke ƙasa). Canjin yanayi da asarar halittu masu yawa ana ganin su da mahimmanci, tunda a kansu, zasu iya tura tsarin Duniya daga jihar Holocene: "canji tsakanin lokutan lokaci a tarihin Duniya galibi ana bayyana su ta hanyar sauye-sauye masu yawa a cikin yanayi, biosphere, ko duka biyun. "

Yarjejeniyar kimiyya ita ce bil'adama ta wuce uku zuwa biyar daga cikin iyakokin duniya tara don amfani da biosphere lafiya kuma yana matsawa sosai a kan wasu da yawa. Da kansa, ƙetare ɗaya daga cikin iyakokin duniya ba ya tabbatar da cewa bil'adama ya wuce ikon ɗaukar ɗan adam na Duniya; watakila ingantaccen fasaha ko sarrafawa mai basira na iya rage wannan damuwa kuma ya dawo da mu cikin sararin samaniya mai aminci. Amma lokacin da aka ƙetare iyakoki da yawa, ya zama da wuya a yi jayayya cewa ba a karya ƙarfin ɗaukar kaya ba. Saboda mutane kalilan ne ke taimakawa wajen rage dukkan matsalolin duniya guda tara, yayin da aka ƙetare iyakoki da yawa, yafi bayyana cewa rage yawan mutane wani bangare ne na abin da ake buƙata don dawowa cikin sararin aiki mai aminci. Girman yawan jama'a a kai a kai yana saman jerin abubuwan da ke haifar da tasirin ɗan adam a kan yanayin halitta a cikin wallafe-wallafen kimiyya na tsarin Duniya. Kwanan nan, mai haɓaka iyakokin duniya Will Steffen da haɗin gwiwar marubuta sun sanya canjin yawan jama'a na duniya a matsayin babban mai nuna tasirin yanayin zamantakewa da tattalin arziki akan aikin tsarin Duniya a zamanin zamani, bayan 1750. 

## Dubi kuma

* Capacity na halitta - Kimanin samar da wasu kayan halittu
* Matsayin muhalli - Bukatar mutum ko rukuni game da yanayi
* Rashin kula da muhalli - Bukatar tsarin halittu wanda ya wuce sake farfadowa
* Yawan jama'a - Lokacin da yawan jinsin ya wuce karfin dake kewaye dashi
* Overshot (yawan jama'a)  - Abinda ke faruwa wanda yawan jama'a na ɗan lokaci ya wuce ƙarfin ɗaukar muhalli
* Ilimin muhalli na yawan jama'a - Ƙananan fannin muhalli
* Ƙaruwar yawan jama'a - Ƙara yawan mutane a cikin yawan jama'a
* r/K ka'idar zaɓe - Ka'idar muhalli game da zaɓin halaye na tarihin rayuwa

## Ƙarin karantawa

* Kin, Cheng Sok, et al. "Tsinkaya da Capacity na Duniya na Jama'a a matsayin Predator da Natural Resources a matsayin Prey a cikin Modified Lotka-Volterra Equations tare da Time-dependent Parameters. " arXiv preprint arXiv:1904.05002 (2019).

## Manazarta