ENVIRONMENTAL ISSUES

OZONE DEPLETION

          The ozone layer is a belt of naturally occurring ozone gas that sits 9.3 to 18.6 miles (15 to 30 kilometers) above Earth and serves as a shield from the harmful ultraviolet B radiation emitted by the sun. Ozone is a highly reactive molecule that contains three oxygen atoms. It is constantly being formed and broken down in the high atmosphere, 6.2 to 31 miles (10 to 50 kilometers) above Earth, in the region called the stratosphere.

           Today, there is widespread concern that the ozone layer is deteriorating due to the release of pollution containing the chemicals chlorine and bromine. Such deterioration allows large amounts of ultraviolet B rays to reach Earth, which can cause skin cancer and harm animals as well.

        One atom of chlorine can destroy more than a hundred thousand ozone molecules, according to the the U.S. Environmental Protection Agency.

GLOBAL WARMING

               Scientific evidence points to the fact that heavy industrialization and pollution have contributed and continue to contribute to rising temperatures. The increase in human population -- from a little over 1.5 billion people at the turn of the twentieth century to close to 7 billion people by 2011 -- combined with the advent of the automobile, industry and especially the burning of fossil fuels, along with the destruction of the rainforest and increased agriculturalization, combine to add to the development of a heat-trapping blanket in the earth's atmosphere. This results in a worldwide rise in temperature. Overpopulation is a contributing factor in the phenomenon of global warming.

GREENHOUSE EFFECT 

       Solar radiation at the frequencies of visible light largely passes through the atmosphere to warm the planetary surface, which then emits this energy at the lower frequencies of infrared thermal radiation. Infrared radiation is absorbed by greenhouse gases, which in turn re-radiate much of the energy to the surface and lower atmosphere. The mechanism is named after the effect of solar radiation passing through glass and warming a greenhouse. The primary greenhouse gases in the Earth's atmosphere are water vapor, carbon dioxide, methane, nitrous oxide, and ozone.

POLLUTION

      A pollutant is a substance or energy introduced into the environment that has undesired effects, or adversely affects the usefulness of a resource. 

ENVIRONMENTAL POLLUTION

        One of the greatest problems that the world is facing today is that of environmental pollution, increasing with every passing year. Environmental pollution are of different types like, air, water, soil and noise and pollution etc.

           Air pollution is by far the most harmful form of pollution in our environment. Air pollution is cause by the injurious smoke emitted by cars, buses, trucks, trains, and factories, namely sulphur dioxide, carbon monoxide and nitrogen oxides. Evidence of increasing air pollution is seen in lung cancer, asthma, allergies, and various breathing problems.  Chlorofluorocarbons (CFC) is a gas, released from refrigerators, air-conditioners,  has slowly damaged the atmosphere and depleted the ozone layer leading to global warming.

        Water pollution. The waste products released into lakes, rivers, and other water bodies, has made marine life no longer hospitable. Humans pollute water with large scale disposal of garbage, flowers, ashes and other household waste. Many diseases are caused in humans by these polluted water.

          Noise pollution include aircraft noise, noise of cars, buses, and trucks, vehicle horns, loudspeakers, and industry noise are extremely harmful for the environment.

         Soil pollution, which can also be called soil contamination, is a result of acid rain, polluted water, fertilizers etc. Soil pollution is not good for crop as well as human beings.

ATMOSPHERIC POLLUTANTS

Smog is a type of air pollutant. This is caused by the burning of large amounts of coal within a city; this smog contains soot particulates from smoke, sulfur dioxide and other components.

Fog is a collection of liquid water droplets or ice crystals suspended in the air at or near the Earth's surface. The term "fog" is typically distinguished from the more generic term "cloud" in that fog is low-lying, and the moisture in the fog is often generated locally (such as from a nearby body of water, like a lake or the ocean, or from nearby moist ground or marshes).

Smoke is a collection of airborne solid and liquid particulates and gases  emitted when a material undergoes combustion.

Soot is impure carbon particles resulting from the incomplete combustion of hydrocarbons.

POPULATION AND ENVIRONMENTAL QUALITY

         Environmental quality is a general term which can refer to varied characteristics that relate to the natural environment as well as the built environment, such as air and water purity or pollution. It is a measure of the condition of an environment relative to the requirements of one or more species and or to any human need or purpose.

       Human population is growing like never before. We are now adding one billion people to the planet every 12 years. That's about 220,000 per day. The list of problems this is causing, or at least complicating, is a long one. It includes shortages of all our resources, war and social conflict, limits on personal freedom, overcrowding and the health and survival of other species.

         Food: one billion people, one out of every seven people alive, go to bed hungry. Every day, 25,000 people die of malnutrition and hunger-related diseases.

       Water Shortages: About one billion people lack access to sufficient water for consumption, agriculture and sanitation.

       Air quality: In many regions of the country, childhood asthma rates have risen dramatically in the past 20 years. Children in undeveloped countries, where people depend on burning wood and dung for their heat and cooking, are also at risk.

       The Ozone Layer The ozone layer is a region of concentrated molecules of a form of oxygen (O3) high above the earth. Without it there would be no life as we know it here because the UV rays from the sun can be very harmful. But various chemicals from human industries, especially chlorofluorocarbons (CFCs), destroy ozone over the course of years

     The World's forests are another resource that is strained by our growing population