As long as the amounts of chlorine and bromine in the atmosphere remain high, one can expect large ozone holes to occur if the stratospheric temperatures remain cold into the spring. According to the WMO/UNEP Scientific Assessment of Ozone Depletion, a statistically significant decline is not expected in the size of the Antarctic ozone hole before 2025. In the meantime, large ozone holes are possible. In the long run, as chlorine and bromine decline, the annually recurring ozone holes will become increasingly smaller, eventually disappearing around 2070.