ABSTRACT
The international regime to protect stratospheric ozone is one of the most effective cases of global environmental policy. Naturally occurring ozone helps to shield the Earth from harmful ultraviolet radiation emitted by the sun. In the 1970s, scientists discovered that chlorofluorocarbons (CFCs) release chlorine into the stratosphere, which then destroys ozone. Discovery of severe ozone depletion above Antarctica, often called the ozone hole, allowed lead states to argue successfully that negotiations on a control Protocol were needed, despite the lack of firm evidence linking the hole to CFCs. Ozone depletion has essentially stabilized and if all countries implement their obligations, the ozone layer should return to normal levels later this century. Several sets of causal factors played central roles in the creation, content, expansion, and extent of success of the ozone regime. Global ozone policy faces challenges that could delay or even prevent full recovery.
