Scientists noticed that the ozone layer was depleting in the 1970s. Ozone concentrations in the atmosphere change naturally due to temperature, weather, latitude, and altitude, and compounds released by natural occurrences such as volcanic eruptions may also have an impact on ozone levels.
However, these natural events could not account for the reported levels of depletion, and scientific data proved that particular man-made substances were to blame. These ozone-depleting compounds were first used in a variety of industrial and consumer applications, namely refrigerators, air conditioners, and fire extinguishers, in the 1970s.
Under the Montreal Protocol, world governments agreed in the late 1980s to safeguard the Earth’s ozone layer by phasing out ozone-depleting compounds released by human activities. The Protocol is implemented in Europe by EU-wide legislation that not only satisfies the Protocol’s aims but also includes harsher, more ambitious requirements.
Global action under the Montreal Protocol has stopped ozone layer loss and enabled it to begin rebuilding, but more work has to be done to maintain a steady rebound.