Tashin matakin teku a duniya ya fara ne tun farkon karni na 20. Tsakanin 1900 da 2016, matakin ruwan teku a duniya ya tashi da 16-21cm (inci 6.3-8.3).[3] Sahihin bayanan da aka tattara daga ma'aunin radar na tauraron dan adam ya nuna saurin tashi na 7.5cm (inci 3.0) daga 1993 zuwa 2017,[4] :1554 wanda yayi kusan 30cm (inci 12) a kowane ƙarni. Wannan hanzarin ya samo asali ne sanadiyyar dumamar yanayi da mutane ke haifarwa, wanda ke haifar da fadada zafin ruwan teku da narkar da manyan kankara.[5] Tsakanin 1993 da 2018, fadada yanayin zafi na tekuna ya ba da kashi 42% zuwa haɓakar teku; narkar da kankara mai matsakaici, 21%; Greenland, 15%; da Antarctica, 8%.[4] Masana kimiyyar yanayi suna tsammanin matakin zai kara sauri yayin karni na 21.[6]
Bayyana matakin teku na gaba yana da kalubale,, saboda ƙwarewar fannoni da yawa na tsarin yanayi. Kamar yadda binciken yanayi game da matakan teku na da da na yanzu ke haifar da ingantattun samfuran kwamfuta, hasashe ya ci gaba da ƙaruwa. A cikin 2007, Kungiyar gwamnatoci a kan Canjin Yanayi (IPCC) ta yi hasashen ƙarshen ƙarshe na 60 cm (ƙafa 2) zuwa 2099,[7] amma rahotonsu na 2014 ya ɗaga ƙididdigar ƙarshen zuwa kusan 90 cm (ƙafa 3).[8] Yawan karatun da aka yi daga baya sun kammala cewa hauhawar matakin teku na duniya zuwa 200 zuwa 270 cm (ƙafa 6.6 zuwa 8.9) wannan karnin "abin yarda ne da jiki".[9][4][10] Kimanin ra'ayin mazan jiya na tsinkayen lokaci shine cewa kowane Celsius digiri na hawan zafin jiki yana haifar da hawan tekun kimanin mita 2.3 (ƙafa 4.2/digiri Fahrenheit) tsawon shekaru millennia biyu (shekaru 2,000): misalin rashin yanayin yanayi.[3]
Matsayin teku ba zai tashi gaba ɗaya a ko'ina cikin Duniya ba, kuma zai ma ɗan faɗi ƙasa a wasu wurare, kamar Arctic.[11] Abubuwan cikin gida sun haɗa da tasirin tectonic da ƙarancin ƙasar, guguwa, ruwa da guguwa. Tashin matakin teku yana iya shafar yawan mutane sosai a yankunan bakin teku da yankunan tsibiri.[12] Ana tsammanin yaduwar ambaliyar bakin ruwa tare da digiri da dama na ɗumamar ɗumi na tsawon shekaru.[13] Karin tasirin shine mafi girman guguwar-hadari da tsunami mafi haɗari, ƙaurawar yawan jama'a, asara da lalacewar ƙasar noma da lalacewa a cikin birane.[14][15] Hakanan an shafi muhalli kamar halittun ruwa, tare da kifaye, tsuntsaye da tsirrai da suka rasa sassan mazauninsu.[16]
KuUngiyoyi na iya amsa hauhawar teku ta hanyoyi daban-daban guda uku: aiwatar da koma baya, saukar da canjin bakin teku, ko don kariya daga hauhawar teku ta hanyar ayyukan gini mai wuyar gaske kamar magudanar ruwa ko hanyoyin taushi kamar gyaran dune da abinci na bakin teku. Wasu lokuta wadannan dabarun karbuwa na tafiya tare hannu bibbiyu, amma a wasu lokutan dole ne a zabi tsakanin dabarun daban-daban.[17] Tsarin halittu da suka dace da hauhawar matakan teku ta motsawa cikin teku bazai yuwu ba koyaushe suyi hakan, saboda shingen halitta ko na wucin gadi.[18].
↑ 4.04.14.2WCRP Global Sea Level Budget Group (2018). "Global sea-level budget 1993–present". Earth System Science Data. 10 (3): 1551–1590. Bibcode:2018ESSD...10.1551W. doi:10.5194/essd-10-1551-2018. This corresponds to a mean sea-level rise of about 7.5 cm over the whole altimetry period. More importantly, the GMSL curve shows a net acceleration, estimated to be at 0.08mm/yr2.
↑IPCC, "Summary for Policymakers", Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, 2007, page 13-14, archived from the original on 2013-03-09, retrieved 2021-01-03"Models used to date do not include uncertainties in climate-carbon cycle feedback nor do they include the full effects of changes in ice sheet flow, because a basis in published literature is lacking."
↑Global and Regional Sea Level Rise Scenarios for the United States(PDF) (Report) (NOAA Technical Report NOS CO-OPS 083 ed.). National Oceanic and Atmospheric Administration. January 2017. p. vi. Retrieved 24 August 2018."The projections and results presented in several peer-reviewed publications provide evidence to support a physically plausible GMSL rise in the range of 2.0 meters (m) to 2.7 m, and recent results regarding Antarctic ice-sheet instability indicate that such outcomes may be more likely than previously thought."
↑Box SYN-1: Sustained warming could lead to severe impacts, p. 5, in: Synopsis, in National Research Council 2011 harvnb error: no target: CITEREFNational_Research_Council2011 (help)