2007 ozone hole larger than in 2008 , ESA says . It covers area of 10.4 million square miles . Ozone layer acts as a sunlight filter , shielding Antarctica from some ultraviolet rays .
2008 ozone hole larger than in 2007 , European Space Agency says . It covers area of about 27 million square kilometers . Ozone layer acts as a sunlight filter , shielding Earth from some ultraviolet rays .