Scientists have shown through direct satellite observations of the ozone hole that levels of ozone-destroying chlorine are declining. Measurements show that the decline in chlorine, resulting from an international ban on chlorine-containing man-made chemicals called chlorofluorocarbons (CFCs), has resulted in about 20% less ozone depletion during the Antarctic winter than there was in 2005, the first year that measurements of chlorine and ozone during the Antarctic winter were made by NASA's Aura satellite.
Rising global emissions of some chlorine-containing chemicals could slow the progress made in healing the ozone layer. A study found the substances, widely used for paint stripping and in the manufacture of PVC, are increasing much faster than previously thought. Mainly produced in China, these compounds are not currently regulated.
The rapid warming of the Antarctic Peninsula, which occurred from the early-1950s to the late 1990s, has paused. Stabilisation of the ozone hole along with natural climate variability were significant in bringing about the change. Together these influences have now caused the northern part of the peninsula to enter a temporary cooling phase.
Not so long ago, humanity stood on the brink of a self-inflicted catastrophe. Our use of ozone-depleting substances such as chlorofluorocarbons (CFCs) had torn a hole in the ozone layer that protects us from the sun’s harmful ultraviolet radiation.
United Nations officials hailed on Tuesday the progress made in reducing damage to the ozone layer and the vital role played by one of the most successful environmental treaties in history in phasing out ozone-depleting substances.
The ozone hole that forms each year in the stratosphere over Antarctica was slightly smaller in 2013 than average in recent decades, according to NASA satellite data. The ozone hole is a seasonal phenomenon that starts to form during the Antarctic spring (August and September). The September-October 2013 average size of the hole was 8.1 million square miles (21 million square kilometers).
The average area covered by the Antarctic ozone hole this year was the second smallest in the last 20 years, according to data from NASA and National Oceanic and Atmospheric Administration (NOAA) satellites. Scientists attribute the change to warmer temperatures in the Antarctic lower stratosphere.
Ultraviolet (UV) radiation has increased three points compared to last September in Santiago de Chile, according to a study released by Chile’s National Cancer Corporation (Conac) and the UV monitoring network of the Universidad de Santiago (USACH).
The ozone layer has seen unprecedented damage in the Arctic this winter due to cold weather in the upper atmosphere. By the end of March, 40% of the ozone in the stratosphere had been destroyed, against a previous record of 30%.