Ozone depletion wind activity. On March 15, 2011, a record ozone layer loss was observed, with about half of the ozone present over the Arctic having been destroyed. The change was attributed to increasingly cold winters in the Arctic stratosphere at an altitude of approximately , a change associated with global warming in a relationship that is still under investigation. By March 25, the ozone loss had become the largest compared to that observed in all previous winters with the possibility that it would become an ozone hole. This would require that the quantities of ozone to fall below 200 Dobson units,
Vienna Convention for the Protection of the Ozone Layer Groups that help facilitate functions under the convention. A Multilateral Fund exists to aid developing nations transition from ozone-depleting chemicals using guidelines under the convention, which is administered by a Multilateral Fund Secretariat. The Multilateral Fund has aided thousands of projects in nearly 150 countries, preventing the usage of roughly 250,000 tons of ozone-depleting chemicals. Vienna Convention for the Protection of the Ozone Layer The Vienna Convention for the Protection of the Ozone Layer is a multilateral environmental agreement signed in 1985 that provided frameworks for international reductions in the production of chlorofluorocarbons due to their contribution to the destruction