Stephen O. Andersen protecting the stratospheric ozone layer. At EPA he rose to Deputy Director for Stratospheric Ozone Protection and then transferred to the Climate Protection Partnerships Division, where he was Director of Strategic Climate Projects until his retirement from government in 2009. The timing of Andersen’s arrival at EPA was fortuitous. 1987 proved to be a watershed moment in the effort to stop ozone depletion, which increased risks of skin cancer and threatened to wipe out crops and ecosystems, among many adverse impacts. The Montreal Protocol on Substances that Deplete the Ozone Layer was agreed on 16 September 1987 and created a
Ozone depletion to increase dramatically as a result of thinning ozone, as well as harming plants and animals. These concerns led to the adoption of the Montreal Protocol in 1987, which bans the production of CFCs, halons and other ozone-depleting chemicals. The ban came into effect in 1989. Ozone levels stabilized by the mid-1990s and began to recover in the 2000s. Recovery is projected to continue over the next century, and the ozone hole is expected to reach pre-1980 levels by around 2075. The Montreal Protocol is considered the most successful international environmental agreement to date. Three forms (or allotropes) of oxygen