Ozone Depletion

The ozone layer is a region in the Earth’s stratosphere that consists mainly of high concentrations of ozones (O3).
It is situated approximately 10 to 50 kilometres above Earth’s surface and it absorbs most of the Sun’s damaging ultraviolet (UV) radiation.

Causes of Ozone Depletion

Ozone depletion is majorly caused by the release of certain man-made chemicals containing chlorine and bromine, such as chlorofluorocarbons (CFCs), halons, carbon tetrachloride, and methyl chloroform.
These chemicals are stable and do not dissolve in rain, so they persist in the atmosphere for many years.
When these chemicals are carried into the ozone layer, they are broken down by solar UV radiation and release chlorine and bromine atoms, which can destroy ozone molecules.

Effects of Ozone Depletion

A reduction in the ozone layer means that more of the Sun’s harmful UV rays reach the earth’s surface, which can cause a variety of environmental and health problems.
It can lead to skin cancers and eye cataracts in humans and animals.
It can also adversely affect crop yields and marine life, especially phytoplankton – the base of the marine food chain.

The Ozone Hole

The term ‘ozone hole’ refers to the severe depletion of the ozone layer over Antarctica, first noticed in the 1980s.
This is not a literal hole, but rather a large area of the stratosphere with extremely reduced ozone, caused by the unique atmospheric conditions over the South Pole and the presence of CFCs.

Regulatory Measures

Realizing the all-encompassing threat posed by ozone depletion, nations came together to sign the Montreal Protocol in 1987, agreeing to phase out the production and consumption of ozone-depleting substances.

Summary

Understanding the causes and effects of ozone depletion, and international steps taken to address it, are vital in battling this global environmental issue.