My Science School

            Sometimes, individual effort is not enough in the grand project of restoring the status quo in the environment. Nation states play an important role in determining the living habits of people of a particular country. Their policy decisions and legislation can make huge impact on the environment. Certain international bodies are necessary in order to persuade governments to control the production and use of substances that harm nature. UNEP is one such organization.

            The United Nations Environment Programme or UNEP is an agency that coordinates its environmental activities, assisting developing countries in implementing environmentally sound policies and practices. Maurice Strong founded the organization and he was its first director too.

            UNEP has played a significant role in developing international environmental conservations and promoting environmental science. The headquarters of the agency was established in Nairobi, Kenya, on 5 June 1972.

             The organization has registered several successes, such as the 1987 Montreal Protocol for limiting emissions of gases blamed for thinning the planet’s protective ozone layer and the 2012 Minamata Convention, a treaty aimed at limiting toxic mercury.

 

          Many organizations like Greenpeace work for conserving nature. World Wide Fund for Nature (WWF) is one such organization that vows to stop further human interference that will harm nature.

          WWF is an international non-governmental organisation founded in 1961, working in the field of the wild life preservation, and the reduction of human impact on the environment. It was formerly named the World Wildlife Fund, which remains its official name in Canada and the United States.

          WWF is the world’s largest conservation organisation with over five million supporters worldwide, working in more than 100 countries, supporting around 1,300 conservation and environmental projects.

          The group aims to “stop the degradation of the planet’s natural environment and to build a future in which humans live in harmony with nature”. Their mission is to conserve nature and reduce the most pressing threats to the diversity on earth.

            Currently, their work is organized around six areas: food, climate, fresh-water, wildlife, forests, and oceans.

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          Now that we know about the dangers of ozone depleting agents, we must definitely try to avoid the use of CFCs in future. However, what about thousands of people who do not know about the dangers of these gases? It is not just the ordinary people, but also various communities, organizations, regions and nations, who must be made aware of the consequences of ozone depletion. Greenpeace is a non-governmental organization that strives to reach this message worldwide.

          With offices in over 39 countries, Greenpeace as an international coordinating body is headquartered in Amsterdam, the Netherlands. Irving Stowe and Dorothy Stowe, Canadian and US expat environmental activists, founded the organization in 1971.

          Greenpeace states that its goal is to “ensure the ability of the earth to nurture life in all its diversity” and focuses its campaigning on worldwide issues such as climate change, deforestation, overfishing, commercial whaling, genetic engineering, and anti-nuclear issues.

          The NGO uses direct action, lobbying and research to achieve its goals. The global organisation does not accept funding from governments, corporations, or political parties, relying on 2.9 million individual supporters and foundation grants.

            Although Chlorofluorocarbons are harmful to the ozone layer, we still use them in various appliances at home. CFCs are used in refrigerators, air-conditioners, solvents and aerosol sprays.

            We know that CFCs cause global warming by trapping heat in the atmosphere. They are instrumental in depleting the ozone layer as well. Once these gases are in the atmosphere, they resist breakdown and do not disappear for many decades. In fact, they can remain in the atmosphere for up to 400 years! It is, therefore, important to reduce the amount of CFCs that are released into the air. One way to do this is to use only CFC –free refrigerators and to avoid the use of air conditioners.

            We should also be careful that any deodorant, spray, solvent or cleaner that we buy is CFC-free. The developing nations of the world have agreed to find substitute chemicals for CFCs. The 1987 Montreal Protocol has reduced the worldwide stock of CFCs and other ozone-destroying compounds by 98 percent. More nations followed suit later. As a result, the ozone layer is expected to recover by the mid – 21st century.

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            The ozone layer is a delicate and sensitive region. Various factors contribute to the breaking down and depletion of the ozone concentrations in the layer. The destruction of the ozone shield will result in the sun’s harmful rays sifting through the resultant holes.

            In the mid-1980s, scientists discovered that the ozone layer was being depleted gradually. The main cause of this, they concluded, was the release of chemicals called Chlorofluorocarbons or CFCs. CFCs are used in industry in a variety of ways and have been amazingly useful in many products. Discovered in the 1930s by American chemist Thomas Midgley, CFCs came to be used in aerosol propellants, refrigerators, home insulation, plastic foam, and throwaway food containers. However, when they escaped to the atmosphere, they adversely affected the ozone particles.

            When CFCs are released into the atmosphere, strong winds can carry them up into the stratosphere where UV rays break them apart, releasing chlorine atoms. Each chlorine atom can attack, and break apart as many as 100,000 ozone molecules during the time it is in the stratosphere. The chlorine from CFCs reduces the amount of ozone in the stratosphere. CFCs also warm the earth’s atmosphere and thus can bring about climate changes all over the planet.

Why does the depletion of the ozone layer pose a danger to us?

                     Man has been instrumental in the gradual deterioration of the ozone layer. When the ozone region is exposed to CFCs, holes are formed in the ozone shield. Through these holes, ultraviolet and other harmful rays of the sun enter the earth’s atmosphere.

                    Even an apparently negligible corrosion of the ozone layer is harmful to us. Every time a small area of the ozone layer is damaged, more ultraviolet light from the sun can reach the earth. One of the most harmful consequences of ozone depletion is that it can cause skin cancer because of the exposure to UV rays. Some researchers say that a tattered ozone layer will also increase the rate of malaria.

                    The environment will also be negatively affected by ozone depletion. The life cycle of plants will change as their food chain is disrupted. Oceans will be hit hard as well. The most basic microscopic organisms such as plankton may not be able to survive if the ozone layer is depleted. The planet’s climate could be adversely affected, as rising heat would alter wind patterns resulting in climate changes throughout the world.

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            The ozone layer covers the entire earth and protects it like a shield from the hazardous rays of the sun. While the ozone shield is formed around the globe, the thickness of the layer is not the same throughout.

            The ozone in the layer is distributed unequally as it is minimum in thickness near the earth’s surface and in the exosphere. Most of it is concentrated in a layer located in the stratosphere several kilometres above the surface of the earth. The thickness of the ozone layer in a vertical column from the surface to the top of the atmosphere is called the total column ozone amount.

            Total ozone varies with latitude over the globe, with the largest values occurring at middle, and high latitudes during all seasons. Total ozone also varies with the seasons, and is in general thicker in spring and thinner during autumn in the northern hemisphere.

            Have you ever worn a pair of glare glasses? In the hot sun, the tinted glasses give comfort to our eyes and protect them from the sun’s harmful rays. The ozone layer does a similar job, protecting the life forms on Earth from the harmful rays of the sun.

            The ozone layer or ozone shield is a region of Earth’s stratosphere that absorbs most of the sun’s ultraviolet radiation. It contains high concentrations of ozone, an inorganic oxygen molecule. The ozone layer is mainly found in the lower portion of the stratosphere and also in the troposphere. The layer was discovered in 1913 by Charles Fabry and Henri Buisson, two distinguished French physicists.

            Ozone in the troposphere pollutes the air there; and this in turn helps the forming of smog. Ozone in the stratosphere protects life on Earth by absorbing some of the sun’s harmful ultra-violet rays. The ozone layer absorbs 97 to 99 percent of the sun’s medium-frequency ultra-violet light, which otherwise would potentially damage exposed life forms near the surface.

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            You must have seen pictures of the beautiful white polar bears that live near the North Pole. These majestic animals live in extreme cold and cannot live elsewhere, where there is no ice.

            However, today, the very existence of these animals is threatened because of climate change. Fondly called the white giants of the Arctic, these glorious animals spend much of their life in, around, or on the water predominantly on sea ice. However, it is a sad fact that sea ice in the Arctic is melting earlier and forming later each year, because of global warming. This means that polar bears are left with less time on the ice to hunt for food, mainly seals, and build up their fat stores for survival in the cold.

            As their ice habitat shrinks, skinnier and hungrier polar bears could become extinct by the end of this century. This would be a tragedy because polar bears help us gain an understanding of what is happening of what is happening throughout the Arctic region. If polar bears are at risk, it may also be an indication that something is terribly wrong with the entire Arctic marine eco-system too.

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               While it is easy to comprehend the dangers of global warming that animals and humans would face because they live on land, it would be interesting to know what would happen to the animals in the oceans. We tend to think that the waters are far safer than the land. However, the truth is quite the contrary. Many sea animals are at high risk.

               Whales and dolphins are at risk because of global warming. Those animals that rely on polar waters, such as belugas, narwhals, and bowhead whales, are likely to be affected by the reduction of sea ice. Less sea ice will allow more commercial shipping, oil, gas, and mining exploration and development, and military activities in previously untouched areas. This will hit nature adversely.

               The oceans will absorb more carbon dioxide, and become more acidic. This means there will be more cetacean disease epidemics, and lower reproductive success and survival rates. Climate change could also mean the end of the 300 or so endangered North Atlantic right whales, as it is affecting their food sources. River dolphins will also suffer from loss of habitat.

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                Man had begun agriculture and farming thousands of years ago. Humans are probably the only species that cultivate and grow their own food in such an elaborate manner. We depend so much on the environmental and climatic conditions that our food habits will be in jeopardy if there is even a slight variation in these circumstances.

                Global warming can have a disastrous impact on agricultural yields. The majority of the world’s one billion poor people depend on agriculture for their livelihood. As mentioned earlier, agriculture, unfortunately, is the human enterprise most vulnerable to changes in climate. Studies have shown that South Asia and Southern Africa are especially at risk because higher temperatures and drops in rainfall could cut yields of the main crops people grow there.

            Droughts or floods have already affected harvests in Russia, Germany, Canada, Argentina, Australia and Pakistan. It is estimated that half the world’s population will face serious food shortages in this century, because of global warming.

            Have you heard that forests are the lungs of the earth? Forests play a crucial role in keeping our planet liveable. When Man, out of his greed, destroys trees with chainsaws, fire and building materials, he is destroying the planet’s biodiversity and habitability.

            About 30 per cent of the world’s land area is covered by forests. However, they are being cut down at an alarming rate, and this is called deforestation. Felling of trees deprives the forest of portions of the canopy that blocks the sun’s rays during the day and holds in heat at night.

            These disruptions lead to more extreme temperature swings that can be harmful to plants and animals.

            Trees also help maintain the water cycle by returning water vapour back into the atmosphere. If there are not enough trees to play this role, many forestlands can quickly turn into barren deserts. Trees also play a critical role in absorbing carbon dioxide. Since more carbon dioxide in the atmosphere will mean increase in the speed and severity of global warming, forests are playing a vital role in preserving life on Earth.

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               We often think that the oceans are stagnant without strong undercurrents. It is a wrong notion! The water in the oceans does move about and has a regular pattern of movement. The movement of the ocean water in certain directions due to various causes is known as ocean currents.

               What moves ocean water? The rotation of the moon around the earth is the major force behind ocean currents. There are circular currents in the north and south of the Pacific and Atlantic oceans. Another key current travels around Antarctica.

               Ocean currents affect climate. The oceans have warm and cold surface currents that act like a global heating and air conditioning system. For example, the Gulf Stream in the North Atlantic Ocean carries warm salty water from the equator up to the coast of Greenland in the Arctic. This water travels near the surface of the ocean. As it travels to the Arctic, the warm water heats the countries of the North Atlantic, like Britain. It then cools down, thus increasing the density of water. The dense water sinks to the bottom, where it is carried back to the equator.

               Global warming is making the ice caps melt, and they will flow into the ocean, and dilute the salty equatorial water. This will make it less dense, and stop it from sinking. In this way, global warming could stop ocean currents, causing drastic climate changes.

               Many factors contribute to global warming. While there are natural causes for this phenomenon, Man has been instrumental in accelerating its pace. One of Man’s many harmful interferences in the affairs of nature is his use of fossil fuels.

               We use fossil fuels like coal, oil and natural gas because they are the cheapest sources of energy available. However, they are also an important cause of global warming. Fossil fuels are formed when organic matter under the surface of the earth decomposes over millions of years. When these fossil fuels are burned for energy, they release a large quantity of carbon dioxide into the air. The presence of carbon dioxide in the air keeps the earth warmer. This is because it traps the heat obtained from sunlight and does not let it go beyond the atmosphere.

               The heat in the atmosphere captured by carbon dioxide will rise proportionately as the percentage of the compound in the air rises significantly. This in turn, leads to an overall rise in the surface temperature of the earth.

               There is no doubt that we depend too much on fossil fuels that release deadly amounts of carbon dioxide into the atmosphere. We need to start considering alternative sources of energy quickly. It is high time we think of other options such as nuclear, solar and wind energy.

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           It is beyond doubt that global warming will affect life on earth in general. However, the intensity of the damage will vary from place to place. This is because global warming primarily causes rise in water levels; and therefore, any place closer to water bodies are at risk.

            Since islands are surrounded by water on all sides, the worst effects of global warming will manifest in islands. Have you heard of an island that disappeared altogether? Rising seas, caused by global warming, have for the first time, washed an island, Lohachara Island of the Hoogly River in West Bengal, off the face of the earth. As the water levels continue to rise, the seas will swallow entire island nations, from the Maldives to the Marshall Islands, inundate vast areas of countries from Bangladesh to Egypt and submerge parts of scores of coastal cities. It is depressing to know that Indonesia has already lost 24 of its islands because of excessive mining and other activities that damage the environment.

            Sea-level rise and increased tropical cyclones are expected to place low-lying small islands in the Pacific, Indian, and Caribbean regions at risk of inundation and population displacement.

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               You must have heard the story of the frog that fell in the cooking pot that was slowly heating up. If man does not realize the imminent danger of global warming, he would face the fate of the frog that could not understand that the water in which it fell was killing it by degrees.

               Global warming affects humankind in diverse ways. It will result in the rise in temperature, which in turn, will cause the polar ice caps to melt. The melting of the ice caps will result in the rise of sea levels; and eventually, the temperature of the ocean will increase. As the temperature of oceans rises, many different species of animals will become endangered. Hurricanes will become more frequent, and much stronger due to the warmer water. These weather changes can have serious effects on the human race and destroy many lives.

               That is not all. The increase in temperature can cause an increase in disease-carrying insects. Around the world, places will become either wetter or drier due to global warming. There will be more droughts, which will lead to famine and starvation. Wetter regions can experience floods, which also cause destruction of life and property. Thus, global warming can indeed be disastrous for the human race.

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