Stratospheric Ozone Depletion
Ozone depletion is a natural phenomenon of the earth’s stratosphere due to the presence of free radicals that are from natural causes such as volcanic activity. However, as man evolved, he discovered his environment and built industries during the industrial revolution. These industries emitted tones of pollutants into the atmosphere, including compounds Ozone Depleting Substances. The continuous use of CFCs also contributes to the effect significantly. The worst case of ozone depletion ever recorded happened in 2006, during winter and early spring in Antarctica. That sounded a loud alarm to environmental scientists, political leaders and civil organizations come up with international strategies and policies that would cut off emissions of ozone depleting compounds and one such policy was Montreal protocol.
Why Stratospheric Ozone Hole Form Over Antarctica
The ozone hole is formed due to the chemical reactions of pollutants in the upper atmosphere that destroy the stratospheric ozone. During winter in the Antarctic, the weather becomes very strange; the strong circular winds form and blow across the entire continent ‘polar vortex' and it airs over Antarctica is isolated from the rest of the world (The Antarctic Ozone Hole, 2016). Polar stratospheric clouds form during this period trapping and concentrating pollutants, hence, accelerating the breakdown of ozone. These pollutants are mainly chlorofluorocarbons and others. The surface of these clouds forms the harbor of extreme chemical reactions that break down ozone.
The ultraviolet light breaks down unstable compounds such as chlorides to produce unstable radicals, that have high electron affinity, ozone is not so stable as the third oxygen is bonded to the oxygen molecule by weak Van Der Waal forces that readily break down in the presence of ultraviolet light. The radicals quickly take up the oxygen radical that also high affinity and form compounds that are stable.
Why the Stratospheric Ozone Hole Form In the spring
Polar stratospheric clouds form during winter and it mainly composed of frozen Ozone Depleting Substance. These clouds form because low winter temperatures and the fact that Antarctica is mainly made of frozen water surfaces unlike arctic that has landed (The Antarctic Ozone Hole, 2016). The surface of these clouds forms the harbor of extreme chemical reactions that break down ozone during spring when these clouds break down. Thermal energy also dissociates ozone, because of its weak force energy from the son readily dissociate ozone to oxygen molecule and an oxygen radical during spring when temperatures elevate.
Chlorofluorocarbons are chemical substances that have relative chemical inertness and that is why it is applied for use in air conditioners, refrigerators, solvents among others ("Ozone's Problem With Polar Stratospheric Clouds"). They have the capability of diffusing into the stratosphere, a property most chemical substances have. They have long atmospheric lifetimes and they constantly dissociate to active radicals that destroy the ozone layer.
Effects of the Stratospheric Ozone Hole
The hole created permits increase levels of shortwave ultraviolet radiations that ozone often filters, from reaching the earth’s surface. These waves cause harm to human health for example, it causes skin cancer, sunburns, and premature aging. It also causes increased causes of blindness and eye cataracts. It also plays a role in weakening the human immune system, hence making us vulnerable to opportunistic diseases (The Impacts of Ozone Depletion, 2016). These rays also have adverse impacts on agriculture and forestry, as it destroys plants that are sensitive to these rays, especially wheat, barley oats among others .It also retards growth of some plants. It also kills certain plankton species, hence threatening marine food chain, hence threatening biodiversity in the oceans (The Impacts Of Ozone Depletion, 2016). It also destroys materials such as wood, fabrics, rubber and several construction materials, hence increasing the cost of replacing these materials. It also reduces winter temperatures over the Antarctic that are way beyond normal ranges (Stratospheric Ozone Depletion, 2016). They also result to wild windstorms that can be incredibly destructive during spring.
What Is Ozone And Where Is It In Our Atmosphere Why Do We Care About The Stratospheric Ozone Hole?
Ozone is a gas made up of three oxygen atoms that are formed when an oxygen atom fuse with oxygen gas, a reaction catalyzed by photochemical energy ‘ultraviolet light' on the earth's stratosphere(The Antarctic Ozone Hole, 2016). The ozone hole is formed when ozone is depleted during chemical reactions in the stratosphere. Destruction of ozone permits destructive ultraviolet light to reach us; hence, affecting our health, it causes the overall cooling trend in Antarctica, increased winds and storms that have increased frequency and strengths.
How Is Stratospheric Ozone Measured How Is Stratospheric Ozone-Depleting From Human Activates?
Ozone amounts are measured using Dodson Units (DU). Emissions from humans lead to ozone depletion
How Severe Is The Depletion Of The Stratospheric Ozone Hole?
The main causes of the depletion of the ozone hole are the human activities such as the burning of fossil fuels and use of chemicals that contain chlorofluorocarbons. For instance, the use of pesticides increases concentration of compounds that participate in ozone depletion (The Antarctic Ozone Hole, 2016). The destruction of ozone is so severe that policies had to be formulated to control further human activities that increase ozone destruction.
According to The Antarctic Ozone, the ozone hole has been growing since the industrial revolution primarily due to human activities. The largest hole ever recorded was 10.6 million miles in the year 2006, and the deepest of its kind. The hole has been fluctuating between 220 and 110 Dobson Units (2016). To control the depletion of the ozone layer, measures and policies have been put in place to control worsening of the effect. The Montreal Protocol was passed to control global emissions and banned the use of chemicals such as Chlorofluorocarbons (CFCs) hence reducing their abundance and, therefore, conserving the ozone layer (The Montreal Protocol, 2016). They agreed that it had to cut CFCs emission by 50%, by making commitments to the treaty that they would formulate and implement policies that will ban ODS from being used in their countries. According The Montreal Protocol, 197 countries made the commitment and it has been one of the most successful treaties signed (2016). There is solid proof that ozone layer is slowly covering and if these efforts continue the ozone levels in the year 2050 will have returned to the 1980 levels if these efforts continue.
The Hydrological Cycle
Hydrological cycle is a complex progression that takes place in the earth's atmosphere, lithosphere, hydrosphere, and biosphere (Description of Hydrologic Cycle, 2016).Water is the most common basic compound on earth, which helps in the sustainability of life of all living things. It drives natural processes such as corrosion, decomposition, growth, and development and geologic formations among others (The Hydrologic Cycle, 2016). The amount of water present in our mother planet has never changed because it continuously circulates in a process known as the hydrological cycle. The process is catalyzed by the energy input from the sun.
Characteristics and Complex Interactions
The process begins when water evaporates from the earth's surface, for instance, from plants, soil, water bodies, rivers or even sublime from ice and snow (The Hydrologic, 2016). The water vapor molecule (H2O) is less dense than most components of the atmosphere such as nitrogen and oxygen.
The water droplets from thick clouds spray back into the ocean or fall to the ground as rain. The water flow on the land as surface flood, but some can infiltrate into the ground. Some of the surface runoff develops into rivers that empty into lakes, swamps, or oceans (Description of Hydrologic Cycle, 2016). Gravity and capillary forces water to infiltrate underground, thus accumulating underground while others seep from the ground forming small streams.
Impact on Human Life and Society
The hydrological cycle is the source of water that is a requirement for our existence, and it is used for domestic and industrial use. The vapor formed to act as a greenhouse gas that reflects heat back to our planet, hence, making it warmer, thus sustaining our existence (Humans and the Water Cycle , 2016). The underground water is the primary source of fresh water used by the man on earth; hence, underground water has to be reserved.
Surface runoff transport minerals from mountain tops and other areas of valleys, making them more fertile and productive. It also transfers chemicals used in agriculture and industries and deposits in lakes contaminating it and causing the death of fish and other animals (Humans and the Water Cycle, 2016). Rain also erodes land surfaces causing land formations that are destructive such as land gullies or impressive landscapes such as falls that usually form tourist attractions in some countries.
References
8(b) The Hydrologic Cycle. (2016). Physicalgeography.net. Retrieved 28 March 2016, from http://www.physicalgeography.net/fundamentals/8b.html
Description of Hydrologic Cycle. (2016). Nwrfc.noaa.gov. Retrieved 28 March 2016, from http://www.nwrfc.noaa.gov/info/water_cycle/hydrology.cgi
Ozone's Problem with Polar Stratospheric Clouds. (2016). Shsu.edu. Retrieved 27 March 2016, from http://www.shsu.edu/~chm_tgc/CHM442/PSC.html
Humans and the water cycle. (2016). Sciencelearn Hub. Retrieved 28 March 2016, from http://sciencelearn.org.nz/Contexts/H2O-On-the-Go/Science-Ideas-and-Concepts/Humans-and-the-water-cycle
("STRATOSPHERIC OZONE DEPLETION", 2016) STRATOSPHERIC OZONE DEPLETION. (2016).People.oregonstate.edu. Retrieved 27 March 2016, from http://people.oregonstate.edu/~muirp/stratozo.htm
The Impacts of Ozone Depletion. (2016). Bcairquality.ca. Retrieved 28 March 2016, from http://www.bcairquality.ca/101/ozone-depletion-impacts.html
The Antarctic Ozone Hole. (2016). Coolantarctica.com. Retrieved 28 March 2016, from http://www.coolantarctica.com/Antarctica%20fact%20file/science/ozone_hole.php
The Impacts of Ozone Depletion. (2016). Bcairquality.ca. Retrieved 28 March 2016, from http://www.bcairquality.ca/101/ozone-depletion-impacts.html
THE MONTREAL PROTOCOL ON SUBSTANCES THAT DEPLETE THE OZONE LAYER | OZONE SECRETARIAT. (2016). Ozone.unep.org. Retrieved 28 March 2016, from http://ozone.unep.org/en/treaties-and-decisions/montreal-protocol-substances-deplete-ozone-layer
