The Recovering Ozone
Busiest cities of the world are currently in lockdown due to the global emergency caused by the new pandemic COVI-19. Following the shutdown of many industrial activities around the world, the earth has come to a pause. Many studies have analyzed the environmental benefits to earth. Such as reduction in air pollution levels, decreased noise pollution and clear waterways due to less industrial effluents.
These environmental changes have given rise to the question, “what is happening to the ozone layer?”
The ozone layer is located in the stratosphere, in which O3 molecules are in higher concentration in the earth’s atmosphere. This layer is the only defence for earth against harmful ultraviolet radiation (UVR).
The ozone layer plays as a protective cover for the earth because the overexposure to the harmful ultraviolet rays could cause various types of problems. Overexposure in human may increase the risk of non-melanoma and malignant melanoma skin cancer, suppress the immune system, accelerate ageing of the skin, increased risk of cataracts and could cause Pterygium.
Studies prove that in the last decade there has been an increase in skin cancer and cataracts all related to ultraviolet B radiation (UVB). However, there’s a lot of uncertainty and debate among the scientist regarding the harmful effects of UV on plants and regarding the role of UVB radiation for the decline of amphibians globally.
In 1980s scientist discovered that ozone is thinning due to human activities. Further, scientists say that ozone thinning throughout the globe is due to meteorological and chemical mechanisms.
A groundbreaking article published in Nature in 1974, explains the threat to the ozone layer from chlorofluorocarbon (CFC) gases. UV rays break down the chlorofluorocarbons, releasing chlorine. One atom of chlorine can destroy more than 100,000 ozone molecules as the free chlorine radicals initiate chain reactions.
In 1987 Environment Protection Agency (EPA) designed the Montreal Protocol. It has several programs in place to protect the ozone from harmful gases by regulating and enforcing on-road car and truck air-conditioning systems, regulating most air-conditioning and refrigeration appliances, Technician certification, Service equipment etc.
Satellite images taken in 1997 showed some decline in ozone-depleting gases. GOME and SCIMACHY monitored the ozone hole for 10 years starting from 1995 to 2004. The results showed a slow recovery of the ozone hole over Antarctica.
On 2019 September 8th NASA and NOAA scientist reported that the ozone hole over Antarctica is smallest since 1982. Further, the scientist said that the annual ozone hole reaches its peak extent of 16.4 million square kilometres and last year it has shrunk to less than 10 million square kilometres. Proving that the Montreal Protocol is working.
Paul Newman, chief scientist for Earth Sciences at NASA’s Goddard Space Flight Center says that “It’s great news for ozone in the Southern Hemisphere, but it’s important to recognize that what we’re seeing this year is due to warmer stratospheric temperatures. It’s not a sign that atmospheric ozone is suddenly on a fast track to recovery.”
A study published in Nature in March 2020, states that the recovery of the ozone is mainly due to the regulations of the Montreal protocol and not because of the current lockdown. Which proves that ozone has been recovering for a long period as the production of harmful gases is controlled.
The Antarctic has been a concern for more than four decades and scientist has observed a hole over Artic in February 2020. Vincent-Henri Peuch, director of the Copernicus Atmosphere Monitoring Service said that “The hole is principally a geophysical curiosity, we monitored unusual dynamic conditions, which drive the process of chemical depletion of ozone. [Those dynamics] allowed for lower temperatures and a more stable vortex than usual over the Arctic, which then triggered the formation of polar stratospheric clouds and the catalytic destruction of ozone.”
Even though the production of ozone-depleting chemicals is drastically reduced, records say that unauthorized emissions are reported from China in 2018.
To ensure the future of the ozone layer, the efforts have to be taken by scientists to create a reliable model to gain a better understanding of the effects ozone depletion has on organisms living within different ecosystems. More studies have to be done to determine biological effects (including human) on UVR exposure and of UV-related damage to other species living in high latitudes and on protective creams and ointments and their efficiency in preventing skin cancer and malignant melanoma.
Moreover, researchers are looking forward to Stations that measure levels of ozone and surface radiation changes in relation to the incidence rate of skin cancer and cataracts to be installed in urban areas and in remote regions far from populations.
By: Fathima Jumana
