The ozone hole over the Antarctic will likely be larger this year than last, as ozone depletion has been usually severe so far this year, the World Meteorological Organization announced yesterday. Ozone depletion normally begins in August, peaks in October, and recovers by early December; the worst depletion was recorded in 1998. This month, four observation stations in the Antarctic reported a decrease in ozone of between 20 and 35 percent compared to the period between 1964 and 1976, before the ozone hole was detected. Although nations have curbed the production and use of many ozone-depleting chemicals, scientists believe it will take decades for the ozone layer to recover fully. The thinner ozone layer means that more harmful UV radiation is hitting the Earth’s surface, and this may lead to a higher incidence of skin cancer.