The North Pole is surrounded by continents that constantly generate a variety of weather conditions. Those frequent storms are what cools the upper atmosphere at the North Pole. For example, says Newman, huge storms generated over the Tibetan Plateau in western China sweep massive amounts of hyper-cold air into the Arctic atmosphere. You get changing weather systems. That leads to a colder polar stratosphere, which then causes more of these clouds to appear that activate chlorine.
Chlorine destroys ozone.
Hurst says adequate improvement won't happen for at least a couple of generations. That effect will be with us for at least the first half of this century. All Rights Reserved. Terms under which this service is provided to you. Read our privacy guidelines .