Scientists have found a large ozone hole in the lower stratosphere over the tropics that can affect 50 per cent of the world’s population. They said that the hole is seven times the size of the Antarctic ozone hole, which only emerges during spring, according to a paper published in AIP Advances.
In his research, Qing-Bin Lu, a professor at the University of Waterloo in Ontario, Canada, has claimed this all-new ozone hole has been there since the 1980s and unlike the Antarctic one, this new ozone hole is present all year round.
The scientist has warned that the presence of this new hole could have disastrous consequences for life on Earth.
“The tropics constitute half the planet’s surface area and are home to about half the world’s population,” Lu said in a press release.
“The existence of the tropical ozone hole may cause a great global concern.”
The tropical regions of the Earth include the Equator and parts of North America, South America, Africa, Asia and Australia.
Ozone hole is not technically a “hole” where no ozone is present, rather it is actually a region of exceptionally depleted ozone layer.
Ozone sits in the upper atmosphere and absorbs ultraviolet radiation, another type of solar energy that's harmful to humans, animals and plants.
Ozone depletion occurs when chlorofluorocarbons (CFCs) and halons—gases formerly found in aerosol spray cans and refrigerants—are released into the atmosphere.
"The depletion of the ozone layer can lead to increased ground-level UV radiation, which can increase risk of skin cancer and cataracts in humans, as well as weaken human immune systems, decrease agricultural productivity, and negatively affect sensitive aquatic organisms and ecosystems,” Lu said.
Lu and his team identified this latest hole by examining average annual ozone changes, differences in annual ozone climatology and changes in temperature over the last few decades.
But his findings have come as a shock to other scientists whose conventional photochemical modelling did not show the large gap.
Dr Marta Abalos Alvarez, Researcher in the department of Physics of the Earth and Astrophysics at the Complutense University of Madrid (UCM), said:
“In my opinion the article lacks the scientific rigour necessary to be a reliable contribution. It contains a lot of reasoning with serious errors and unsubstantiated assertions, contradicting previous results that are substantiated. Ozone depletion in the tropics is nothing new and is mainly due to the acceleration of the Brewer-Dobson circulation. Finally, the journal in which it is published has a very low impact factor.”
