How is the ozone layer affected?
Ozone depletion occurs when chlorofluorocarbons (CFCs) and halons—gases formerly found in aerosol spray cans and refrigerants—are released into the atmosphere (see details below). CFCs and halons cause chemical reactions that break down ozone molecules, reducing ozone’s ultraviolet radiation-absorbing capacity.
What are the effects of ozone depletion Class 12?
(ii) The two ill-effects that ozone depletion can cause in human body are: Allows UV-B radiation to enter atmosphere that increases mutation and damages DNA. Causes ageing of skin and damage to skin cells and cancer. Inflammation of cornea (snow blindness), cataract, etc.
Why hydrofluorocarbons are no harm to the ozone layer?
“HFCs are, in fact, weak ozone-depleting substances.” While HCFCs contain chlorine atoms, they are less damaging to the ozone layer because they also contain hydrogen atoms, which causes them to break down in the atmosphere faster. HCFCs are currently being phased out in favor of HFCs, which do not contain chlorine.
What is the current state of the ozone layer 2021?
Credits: NASA Ozone Watch On 27 October, NASA and NOAA confirmed the 2021 ozone hole reached its maximum area on October 7, peaking at 9.6 million square miles (24.8 million square kilometers) – roughly the size of North America – ranking it the 13th largest since 1979.
How has the ozone layer changed over time?
Global emissions of ozone-depleting substances have declined by more than 99\% since 1986 (the year before international action was agreed). Ozone layer thickness declined, and the Antarctic ozone hole grew substantially from the 1980s through to the early 2000s.
What will replace hydrofluorocarbons?
In chillers, hydrocarbons and ammonia are safe and energy-efficient alternatives to HFCs, both under moderate and high ambient temperature conditions. Heat pumps are also used with hydrocarbons, additionally CO2 is available on the market.