http___metro-portal.hr_ozonska-rupa-iznad-antarktike-najmanja-od-1988_109583_1.xml
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Lingering pollutants, called chlorofluorocarbons, and cold temperatures high in the atmosphere have conspired to create record loss of the protective ozone layer above the Arctic, the World Meteorological Organization reports. At about 12.4 miles (20 kilometers) above the Earth in the stratosphere where the ozone layer is normally concentrated, most of it has been depleted, said Markus Rex, an ozone researcher with the Alfred Wegener Institute for Polar and Marine Research in Germany. [Earth's Atmosphere: Top to Bottom] In mid-March, Rex and other researchers from Europe, Russia and North America warned that, despite a successful international plan to ban the use of ozone-depleting substances, the Arctic could be facing unprecedented ozone loss this spring. The ozone layer blocks harmful radiation — which can damage DNA and lead to skin cancer, among other problems — preventing it from reaching the Earth's surface. In 1987, under the Montreal Protocol, countries agreed to end production of ozone-destroying substances, including CFCs. However, these pollutants are still lingering in the air, and are expected to continue causing ozone losses for decades. Ozone loss originates inside a polar vortex, which is created by a combination of cold temperatures and the rotation of the Earth. The cold leads to cloud formation and chemical reactions that turn the pollutants into highly reactive molecules that break apart the three oxygen atoms of ozone. The result: loss of the ozone shield. The similar, but more pronounced, dynamics are responsible for the more infamous ozone hole above Antarctica. The warmer temperatures of spring will ultimately end the depletion, Rex told LiveScience. "These days temperatures are still cold, but they are predicted to warm up soon so we would think the ozone less period would be over in about 10 days from now." You can follow LiveScience writer Wynne Parry on Twitter @Wynne_Parry.
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Ozonska rupa iznad Antarktike najmanja od 1988. Znanstvenici tvrde kako njihove satelitske snimke prvi put dokazuju da se smanjuje koncentracija klora koji razara ozonski omotač Ozonske rupe malo su se povukle s naslovnica, ustupivši mjesto ostalih katastrofalnim posljedicama ljudskog nemara, no ovu vijest vrijedi objaviti kako bi se pokazalo da se zajedničkim snagama ipak nešto može. Naime, najnovije istraživanje koje je provela NASA jasno je potvrdilo da se svijet može ujediniti u sprječavanju ekoloških katastrofa i ispraviti pogreške. Ozonska rupa iznad Antarktike pokazuje znakove oporavka. Znanstvenici tvrde kako njihove satelitske snimke prvi put dokazuju da se smanjuje koncentracija klora koji razara ozonski omotač, a tu pozitivnu promjenu izravno povezuju s preventivnim djelovanjem čovječanstva, započetim još 80-ih godina prošlog stoljeća. Ozonski omotač iznad Antarktike otvori se svakog rujna, a rupa je 2017. bila veličine 20 milijuna m2, što je ispod prosjeka od 26 milijuna m2. Također, to je najmanja površina ozonske rupe od 1988. godine. Znači, možda ipak ima vremena za nas...