{"id":73516,"date":"2025-03-03T00:12:52","date_gmt":"2025-03-02T23:12:52","guid":{"rendered":"https:\/\/www.infokuryr.cz\/n\/?p=73516"},"modified":"2025-03-02T14:16:41","modified_gmt":"2025-03-02T13:16:41","slug":"gronsky-ledovec-v-bode-zlomu-nova-panicka-studie-vyvolava-kontroverze","status":"publish","type":"post","link":"https:\/\/www.infokuryr.cz\/n\/2025\/03\/03\/gronsky-ledovec-v-bode-zlomu-nova-panicka-studie-vyvolava-kontroverze\/","title":{"rendered":"Gr\u00f3nsk\u00fd ledovec v bod\u011b zlomu? Nov\u00e1 panick\u00e1 studie vyvol\u00e1v\u00e1 kontroverze"},"content":{"rendered":"
<\/div>\n

Na z\u00e1klad\u011b nep\u0159esn\u00fdch model\u016f extr\u00e9mn\u00edho klimatu prob\u00edh\u00e1 dal\u0161\u00ed pokus vyvolat pomoc\u00ed studie paniku z ledu v Gr\u00f3nsku. Tamn\u00ed ledov\u00e1 pokr\u00fdvka p\u0159e\u010dkala v pr\u016fb\u011bhu historie bez \u00fahony v\u00fdrazn\u011b vy\u0161\u0161\u00ed teploty. Glob\u00e1ln\u00ed klimatick\u00fd syst\u00e9m je prost\u011b p\u0159\u00edli\u0161 slo\u017eit\u00fd na to, aby se dal sbalit do jednoduch\u00fdch model\u016f.<\/span><\/strong><\/p>\n

Nov\u00e1 studie zp\u016fsobuje rozruch ve v\u00fdzkumu klimatu a tvrd\u00ed, \u017ee identifikovala mo\u017en\u00fd \u201ebod zlomu\u201c pro \u00fapln\u00e9 t\u00e1n\u00ed gr\u00f3nsk\u00e9ho ledovce. Pr\u00e1ce Petriniho a kol., publikovan\u00e1 v \u010dasopise \u201eThe Cryosphere\u201c, s n\u00e1zvem \u201e\u00a0<\/span>Topograficky kontrolovan\u00fd bod zlomu pro \u00fapln\u00e9 t\u00e1n\u00ed gr\u00f3nsk\u00e9ho ledovce<\/span><\/a>\u00a0\u201c p\u0159edpov\u00edd\u00e1 dramatick\u00e9 d\u016fsledky, pokud glob\u00e1ln\u00ed oteplen\u00ed dos\u00e1hne 3,4 stupn\u011b Celsia nad p\u0159edindustri\u00e1ln\u00ed \u00farove\u0148.<\/span><\/p>\n

V\u011bdci sv\u00e1 zji\u0161t\u011bn\u00ed zakl\u00e1daj\u00ed na po\u010d\u00edta\u010dov\u00fdch simulac\u00edch vyu\u017e\u00edvaj\u00edc\u00edch model komunitn\u00edho ledov\u00e9ho pl\u00e1tu (CISM2) ve spojen\u00ed s modelem komunitn\u00edho zemsk\u00e9ho syst\u00e9mu (CESM2). Podle jejich v\u00fdpo\u010dt\u016f by i mal\u00e1 zm\u011bna bilance povrchov\u00e9 hmotnosti (SMB) z 255 na 230 gigatun za rok mohla sta\u010dit k tomu, aby se dal do pohybu proces, kter\u00fd by vedl k t\u00e9m\u011b\u0159 \u00fapln\u00e9mu t\u00e1n\u00ed ledovce. Ale jak spolehliv\u00e9 jsou tyto p\u0159edpov\u011bdi ve skute\u010dnosti? Studie vyvol\u00e1v\u00e1 z\u00e1sadn\u00ed ot\u00e1zky t\u00fdkaj\u00edc\u00ed se metodologie a interpretace klimatick\u00fdch model\u016f, kter\u00e9 vy\u017eaduj\u00ed kritick\u00e9 zv\u00e1\u017een\u00ed.<\/span><\/p>\n

P\u0159edpov\u011bdi zalo\u017een\u00e9 na modelech pod mikroskopem<\/span><\/h2>\n

J\u00e1dro studie je zalo\u017eeno na po\u010d\u00edta\u010dov\u00fdch modelech, kter\u00e9 funguj\u00ed za p\u0159edpokladu \u201evysok\u00fdch emis\u00ed CO\u2082\u201c. P\u0159esn\u00e1 emisn\u00ed k\u0159ivka, na kter\u00e9 jsou simulace zalo\u017eeny, z\u016fst\u00e1v\u00e1 nejasn\u00e1. To je pozoruhodn\u00e9, proto\u017ee mnoho klimatick\u00fdch studi\u00ed spol\u00e9h\u00e1 na extr\u00e9mn\u00ed sc\u00e9n\u00e1\u0159e, jako je RCP8.5, o kter\u00fdch kritici \u0159\u00edkaj\u00ed, \u017ee jsou nerealistick\u00e9, proto\u017ee p\u0159edpokl\u00e1daj\u00ed t\u00e9m\u011b\u0159 exponenci\u00e1ln\u00ed n\u00e1r\u016fst emis\u00ed CO\u2082.<\/span><\/p>\n

Auto\u0159i popisuj\u00ed mechanismus, kdy t\u00e1n\u00ed na povrchu vede ke sn\u00ed\u017een\u00ed nadmo\u0159sk\u00e9 v\u00fd\u0161ky, co\u017e n\u00e1sledn\u011b zvy\u0161uje teplotu a podporuje dal\u0161\u00ed t\u00e1n\u00ed. P\u0159edpokl\u00e1d\u00e1 se, \u017ee tento proces, zn\u00e1m\u00fd jako \u201eSMB height feedback\u201c, p\u0159ev\u00e1\u017e\u00ed protip\u016fsob\u00edc\u00ed \u00fa\u010dinek ledovcov\u00e9 izostatick\u00e9 \u00fapravy (GIA) \u2013 zvednut\u00ed podpovrchu po reli\u00e9fu taj\u00edc\u00edm ledem \u2013 a t\u00edm uvedl do pohybu za\u010darovan\u00fd kruh.<\/span><\/p>\n

Zvl\u00e1\u0161t\u011b zaj\u00edmav\u00e9 je pozorov\u00e1n\u00ed v\u00fdzkumn\u00edk\u016f, \u017ee topografie ve st\u0159edn\u00edm z\u00e1padn\u00edm Gr\u00f3nsku hraje rozhoduj\u00edc\u00ed roli. Domn\u00edvaj\u00ed se, \u017ee to byla pr\u00e1v\u011b tato oblast, kter\u00e1 zabr\u00e1nila \u00fapln\u00e9mu vymizen\u00ed ledov\u00e9 pokr\u00fdvky b\u011bhem posledn\u00edho tepl\u00e9ho obdob\u00ed p\u0159ed asi 130 000\u2013115 000 lety \u2013 p\u0159esto\u017ee byly tehdy teploty vy\u0161\u0161\u00ed ne\u017e dnes.<\/span><\/p>\n

Mezi v\u011bdou a alarmismem<\/span><\/h2>\n

Studie se p\u0159ipojuje k rostouc\u00edmu po\u010dtu publikac\u00ed varuj\u00edc\u00edch p\u0159ed dramatick\u00fdmi \u201ebody zlomu\u201c v klimatick\u00e9m syst\u00e9mu. Takov\u00e9 sc\u00e9n\u00e1\u0159e jsou ide\u00e1ln\u00ed pro titulky, ale jejich v\u011bdeck\u00fd z\u00e1klad \u010dasto zaost\u00e1v\u00e1 za medi\u00e1ln\u00edm ohlasem.<\/span><\/p>\n

Pozoruhodn\u00fd je tak\u00e9 \u010dasov\u00fd r\u00e1mec: simulace pokr\u00fdvaj\u00ed tis\u00edcilet\u00ed \u2013 obdob\u00ed, ve kter\u00e9m m\u016f\u017ee v\u00fdvoj ovlivnit nespo\u010det nep\u0159edv\u00eddateln\u00fdch faktor\u016f. P\u0159esnost klimatick\u00fdch model\u016f rychle kles\u00e1 s rostouc\u00ed d\u00e9lkou p\u0159edpov\u011bdi, co\u017e z\u00e1sadn\u011b zpochyb\u0148uje spolehlivost takov\u00fdch dlouhodob\u00fdch sc\u00e9n\u00e1\u0159\u016f.<\/span><\/p>\n

Historick\u00e1 data tak\u00e9 ukazuj\u00ed, \u017ee gr\u00f3nsk\u00fd ledov\u00fd p\u0159\u00edkrov odolal teplot\u00e1m v\u00fdrazn\u011b vy\u0161\u0161\u00edm ne\u017e dne\u0161n\u00ed b\u011bhem holoc\u00e9nn\u00edho klimatick\u00e9ho optima asi p\u0159ed 8 000 a\u017e 5 000 lety. To ukazuje na vy\u0161\u0161\u00ed \u00farove\u0148 odolnosti, ne\u017e nazna\u010duj\u00ed sou\u010dasn\u00e9 modely.<\/span><\/p>\n

V\u011bdeck\u00e9 financov\u00e1n\u00ed a pozornost m\u00e9di\u00ed<\/span><\/h2>\n

Nen\u00ed \u017e\u00e1dn\u00fdm tajemstv\u00edm, \u017ee dramatick\u00e9 v\u00fdsledky v\u00fdzkumu p\u0159itahuj\u00ed v\u00edce pozornosti ne\u017e um\u00edrn\u011bn\u00e9 progn\u00f3zy. To vyvol\u00e1v\u00e1 ot\u00e1zku, do jak\u00e9 m\u00edry ovliv\u0148uje financov\u00e1n\u00ed v\u00fdzkumu a medi\u00e1ln\u00ed zpravodajstv\u00ed sm\u011br v\u011bdeck\u00fdch studi\u00ed.<\/span><\/p>\n

Sami auto\u0159i p\u0159izn\u00e1vaj\u00ed, \u017ee jejich v\u00fdsledky z\u00e1vis\u00ed na pou\u017eit\u00fdch modelech a \u017ee je nutn\u00fd dal\u0161\u00ed v\u00fdzkum. Tato omezen\u00ed jsou v\u0161ak jen z\u0159\u00eddka br\u00e1na v \u00favahu ve ve\u0159ejn\u00e9 diskusi, kde jsou slo\u017eit\u00e9 v\u011bdeck\u00e9 kontexty \u010dasto redukov\u00e1ny na zjednodu\u0161en\u00e1 sd\u011blen\u00ed.<\/span><\/p>\n

Skute\u010dn\u00e1 pozorov\u00e1n\u00ed versus modelov\u00e9 projekce<\/span><\/h2>\n

Zat\u00edmco Gr\u00f3nsko v posledn\u00edch desetilet\u00edch skute\u010dn\u011b ztratilo ledovou hmotu, satelitn\u00ed m\u011b\u0159en\u00ed ukazuj\u00ed diferencovan\u011bj\u0161\u00ed obraz ne\u017e modelov\u00e9 projekce. P\u0159irozen\u00e9 kol\u00eds\u00e1n\u00ed ledov\u00e9 hmoty s obdob\u00edmi t\u00e1n\u00ed a r\u016fstu nemus\u00ed b\u00fdt v modelech dostate\u010dn\u011b zohledn\u011bno.<\/span><\/p>\n

Paleoklimatick\u00e1 data nav\u00edc nazna\u010duj\u00ed, \u017ee gr\u00f3nsk\u00fd ledov\u00fd p\u0159\u00edkrov zcela nezmizel ani b\u011bhem p\u0159edchoz\u00edch tepl\u00fdch obdob\u00ed. Ochrann\u00fd efekt topografie ve st\u0159edoz\u00e1padn\u00edm Gr\u00f3nsku, zd\u016fraz\u0148ovan\u00fd samotn\u00fdmi v\u00fdzkumn\u00edky, hovo\u0159\u00ed proti katastrofick\u00e9mu sc\u00e9n\u00e1\u0159i, a to i za podm\u00ednek extr\u00e9mn\u00edho oteplov\u00e1n\u00ed.<\/span><\/p>\n

Z\u00e1v\u011br: M\u00edsto alarmismu v\u011bdeck\u00e1 pe\u010dlivost<\/span><\/h2>\n

Studie Petriniho a kol. poskytuje cenn\u00e9 poznatky o mo\u017en\u00fdch mechanismech t\u00e1n\u00ed ledu v Gr\u00f3nsku. Z\u00e1rove\u0148 ilustruje omezen\u00ed modelov\u00fdch klimatick\u00fdch p\u0159edpov\u011bd\u00ed, zejm\u00e9na v obdob\u00edch n\u011bkolika tis\u00edcilet\u00ed.<\/span><\/p>\n

Odpov\u011bdn\u00e1 klimatick\u00e1 politika by m\u011bla b\u00fdt zalo\u017eena na spolehliv\u00fdch v\u011bdeck\u00fdch d\u016fkazech, nikoli na extr\u00e9mn\u00edch sc\u00e9n\u00e1\u0159\u00edch s n\u00edzkou pravd\u011bpodobnost\u00ed v\u00fdskytu. Slo\u017eitost klimatick\u00e9ho syst\u00e9mu vy\u017eaduje diferencovan\u00fd p\u0159\u00edstup, kter\u00fd adekv\u00e1tn\u011b zohled\u0148uje jak rizika zm\u011bny klimatu, tak nejistoty v p\u0159edpov\u011bdn\u00edch modelech.<\/span><\/p>\n

\"\"<\/p>\n

 <\/p>\n","protected":false},"excerpt":{"rendered":"

Na z\u00e1klad\u011b nep\u0159esn\u00fdch model\u016f extr\u00e9mn\u00edho klimatu prob\u00edh\u00e1 dal\u0161\u00ed pokus vyvolat pomoc\u00ed studie paniku z ledu…<\/p>\n","protected":false},"author":2,"featured_media":73517,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[7],"tags":[3484,873,1503,1213],"_links":{"self":[{"href":"https:\/\/www.infokuryr.cz\/n\/wp-json\/wp\/v2\/posts\/73516"}],"collection":[{"href":"https:\/\/www.infokuryr.cz\/n\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.infokuryr.cz\/n\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.infokuryr.cz\/n\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.infokuryr.cz\/n\/wp-json\/wp\/v2\/comments?post=73516"}],"version-history":[{"count":0,"href":"https:\/\/www.infokuryr.cz\/n\/wp-json\/wp\/v2\/posts\/73516\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.infokuryr.cz\/n\/wp-json\/wp\/v2\/media\/73517"}],"wp:attachment":[{"href":"https:\/\/www.infokuryr.cz\/n\/wp-json\/wp\/v2\/media?parent=73516"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.infokuryr.cz\/n\/wp-json\/wp\/v2\/categories?post=73516"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.infokuryr.cz\/n\/wp-json\/wp\/v2\/tags?post=73516"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}