In his millenium report, Kofi Annan described the Montreal Protocol set to ban the use of chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) as “The single most successful international agreement to date…“ These molecules, which contain chlorine and are often used for insulation and refrigeration, are considered by scientists as strong greenhouse gases. They have greatly contributed to the depletion of the ozone layer. Restricting their use, according to strict measures resulting from negotiations by those who signed the protocol, has had a very positive effect on global warming. Certain American researchers have estimated a reduction equivalent to 8 billion tons of carbon dioxyde (study published March 2007 in the American journal PNAS (Proceedings of the National Academy of Sciences) and reported in Le Monde in September 2007.
Despite positive progress, scientists warn about the appearance of new dangers. The Antarctic Sun reports that the ozone layer situation continues to be a problem and is getting worse. The magazine states that the hole in the ozone layer has reached 29,5 million km², an area greater than all of Antarctica. Other observations have recently been published in sources such as the American scientific journal Nature, revealing that new ozone loss has been detected at the poles, due to chemical interactions between molecules that the scientists had not anticipated in their models.
Emma Young from the New Scientist elaborates on the consequences of ozone depletion and brings attention to the problematic reduction of phytoplankton due to the impact of stronger UV rays in the atmosphere. The disappearance of this crucial species which feeds a large number of marine species is very alarming in this area of the world.
The Montreal protocol has proved the international community capable of providing urgent solutions to environmental problems. Nevertheless, scientific progress seems to show that it is still too early to consider that the hole in the ozone layer as a resolved problem. Its consequences have already seriously affected the Earth's ecosystems.
Iceberg - Terre Adélie - Antarctica © Yann Arthus-Bertrand