The world is celebrating Monday, 16 September, the International Day for the Conservation of the Ozone Layer.
The ozone layer is a fragile shield of gas that protects Earth from the harmful part of the sun's rays, helping to preserve life on the planet, according to the United Nations website.
The phasing out of the tight use of ozone-depleting substances and related reductions has not only protected the ozone layer of this and future generations, but has also contributed significantly to global efforts to address climate change, FAO says. Moreover, it protects human health and ecosystems by reducing harmful UV rays from reaching the Earth.
The theme for the 2019 celebration is "32 years of Protocol and Ozone Recovery," and is intended to celebrate three decades of remarkable international cooperation to protect the ozone layer and climate under the Montreal Protocol. The slogan is a reminder of the need to maintain momentum to ensure the safety and health of the planet.
The Montreal Protocol has phased out 99% of the ozone-consuming chemicals used in refrigerators, air conditioners and a number of other products.
The most recent scientific assessment of ozone depletion, completed in 2018, shows that parts of the ozone layer have recovered at a rate of 1-3% per decade since 2000. Under projected rates, the northern hemisphere and mid-latitude ozone layer will fully recover by 2030 The southern hemisphere will recover by 2050, while the polar regions will recover by 2060.
Efforts to protect the ozone layer contributed to combating climate change by avoiding an estimated 135 billion tonnes of CO2 equivalent emissions between 1990 and 2010.
Professor Raed Mohammed Suleiman, an astrophysicist at the Harvard Smithsonian Center for Astrophysics, said that ozone is an active reactive gas naturally present in our atmosphere. ).
Ozone is found in two atmospheric regions: the troposphere, which is closest to the Earth, from the Earth's surface to about 10 and 15 kilometers. And the stratosphere between the troposphere and an altitude of about fifty kilometers.
About 10% of the ozone is in the troposphere and the rest is in the stratosphere. This large amount of stratospheric ozone is often referred to as the "ozone layer".
He adds that ozone in the stratosphere protects life on Earth by absorbing the sun's ultraviolet rays, and its depletion can lead to increased amounts of ultraviolet radiation reaching the Earth, which could lead to more cases of skin cancer, cataracts, and weakened organs. Immunity.
Ultraviolet radiation can also damage crops and reduce their quantities.