Il buco dell'ozono nell’emisfero meridionale ha raggiunto l'estensione minima registrata dall'anno della sua scoperta, nel 1982, con una superficie di 10 milioni di chilometri quadrati. Ad indicarlo sono i dati dei satelliti della NASA e dell'Ente americano per le ricerche su atmosfera e oceani.
Il restringimento è stato causato dal riscaldamento record avvenuto nella stratosfera, ossia la fascia dell'atmosfera in cui si trova il gas alla quota di circa 20 chilometri. Nello specifico, le temperature più alte riducono la formazione delle nuvole nelle quali si concentrano i composti che lo distruggono, ossia cloro e bromo.
Ad indicarlo sono i dati dei satelliti della NASA
"La notizia è ottima ma bisogna riconoscere che non è un segno che la situazione stia migliorando", ha affermato alla SFR Stefan Reimann del Laboratorio federale svizzero di prova dei materiali e di ricerca.
"Inoltre non è collegata ai cambiamenti climatici poiché sono principalmente influenzati dall'anidride carbonica e da altri gas serra nello strato più basso, alto dieci chilometri, la cosiddetta troposfera", ha sottolineato.
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