Ozone (O3) is a pale blue colored gas which consists of three oxygen atoms, and creates a shield for us in the Earth’s stratosphere, about 160,000 feet above the Earth’s surface. It absorbs most of the Sun’s UV radiation. Scientists believe that as global warming and greenhouse gases increase in the atmosphere, the protective ozone layer will get weaker. This is because as the Earth’s surface temperature rises, the stratosphere will get colder, making the natural process of ozone layer repair slower.
The ozone layer, which protects life on Earth from the harmful rays of the Sun has been depleting for many years now. This is due to greenhouse gases and an increase in air pollution, despite the progress made over the years since the Montreal Protocol which took effect in 1989.
Currently scientists have identified more ozone depleting gases such as that HCFCs and HFCs which are potent greenhouse gases, destroying the high-altitude ozone layer and exposing us to harmful ultraviolet rays of the sun. (TreeHugger)
Ozone layer- the latest NASA Pictures
According to an article posted at the National Aeronautics and Space Administration, NASA’s official website, titled NASA Visible Earth: Largest-ever Ozone Hole over Antarctica, NASA’s instruments have detected that the ozone layer over the Antarctic region, which scientists call an “ozone depletion area,” has grown three times larger than the entire land mass of the United States—the largest such area ever observed.
In another article published on the NASA Science site, titled: 2014 Ozone Hole Update NASA has said that “The Antarctic ozone hole reached its annual peak size on Sept. 11, according to scientists from NASA and the National Oceanic and Atmospheric Administration (NOAA). The size of this year’s hole was 24.1 million square kilometers (9.3 million square miles) — an area roughly the size of North America.”
The images found on the NASA’s public domain show the “hole” on September 11 and September 30th of 2014. The single-day maximum area was similar to that in 2013, which reached 24.0 million square kilometers (9.3 million square miles). The largest single-day ozone hole ever recorded by satellite was 29.9 million square kilometers (11.5 million square miles) on Sept. 9, 2000. Overall, the 2014 ozone hole is smaller than the large holes of the 1998–2006 period, and is comparable to 2010, 2012, and 2013.
Since the Montreal Protocol came into effect, the ozone-depleting substances over Antarctica has declined about 9% below the record maximum recorded in the year 2000.
(Source: 2014 Ozone Hole Update – NASA Science)
The Health & Environmental Impacts of Ozone Depletion
The ozone layer of the stratosphere filters out most of the harmful ultra violate radiation and shortwave radiation from the sun. If the ozone layer is depleted, then more harmful rays will reach the surface of the Earth, which could have serious impacts on human health, plants, animals, and environment. The impacts of depleted ozone are given below.
1. Effects on Human Health
In laboratory and epidemiological studies, it has been found that the Sun’s UVB rays cause nonmelanoma skin cancer and plays a major role in malignant melanoma development. UV rays have also been linked with cataract, a disease that clouds the lenses of the eyes and causes blindness. It is therefore important to protect your skin and eyes from Sun’s UVB rays.
2. Effects on Plants
UVB rays will affect agriculture, forestry and natural ecosystems. Plants’ growth and metabolism are greatly affected by the amount of UVB present in sunlight. Even though plants are equipped with repair mechanisms to reduce these effects, UVB radiation can directly affect plant growth, competitive balance, bio-geochemical cycles and cause plant diseases.
3. Effects on Marine Ecosystems
In particular, plankton (tiny organisms in the surface layer of oceans) are threatened by increased UV radiation. Plankton are the first vital step in aquatic food chain. Decreases in plankton could disrupt the fresh and saltwater food chains, and lead to a species shift in our waters. Loss of biodiversity in our oceans, rivers and lakes could reduce fish yields for commercial and sport fisheries. (Source: bcairquality.ca)
4. Effects on Biogeochemical Cycles
Increases in solar UV radiation could affect terrestrial and aquatic biogeochemical cycles. It would alter greenhouse and chemically-important trace gases e.g., carbon dioxide (CO2), carbon monoxide (CO), carbonyl sulfide (COS) and possibly other gases, including ozone.(Source: epa.gov)
5. Effects on Materials
The Sun’s harmful radiationis known to cause damage to most synthetic polymers, biopolymers, naturally occurring as well as some other commercial materials. The materials available today are somewhat protected by an additive layer, but any increase in the UVB levels would breakdown materials faster.
So, now you know the dangers of Sun’s Ultra Violet rays. Always take precaution when you leave the house and are exposed to sunlight, especially when leaving the house between the hours of 10 AM and 3 PM. Use plenty of sun block and use protective glasses for your eyes.
We should also take precautions to protect the globe and our environment and do things that reduce our negative impacts on the globe. Use materials that do not deplete the ozone, such as using air conditioners, refrigerators and aerosols that do not contain any CFC or other ozone depleting gases. We can all try to do things that reduce our overall impact on the globe so that we can improve the general health of the planet, and make the planet safer for future generations to come.
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