We are guests in this world; at the same time, we are hosts too. We have come as guests and are converted into hosts. That is the law of nature.  Everyone has a right to live here a healthy and peaceful life. It is our responsibility to make the world a good place to live. But, we are not the makers of the world; we are the breakers. We break everything; we break laws and justice, we break ethics and etiquette; and we break anything that we are supposed to follow. We do not think about the consequences. We are not aware of the aftermath……

Through millions of years since its formation, earth has warmed and cooled several times, climate has changed many times due to its delicate orbital shift, and the atmosphere changed every time there was a variation in solar energy. And for the last hundred years we, the human race, have become a predominant force that disturbs the moods and vibrations of earth. We influence the comings and goings of springs and summers; we influence the warmth and coolness of the Mother Earth; we control the tears and drought of Mother Nature. The global warming is a phenomenon that appeared a quite number of times in the past, but it was considerably a very slow process. But with the human involvement, global warming has accelerated over the last hundred years and is expected to be extremely faster in the next century. Nobody else is to be blamed; we are responsible for where we are now.

What is Global Warming?

Global warming is the phenomenon of unusual and substantial increase in the surface temperature of earth, basically due to the greenhouse gases produced as a result of the activities of human beings. It was found that there was an increase of 0.6 to 0.9 degree Celsius in the average surface temperature of the earth during the hundred year period starting from 1906 to 2005, which is highly significant in global warming. The rate of warming is found to be almost doubled during the last 50 years compared to the trend during the last 100 years.

Warming due to Natural Cause

During the earlier periods, before the advent of industrial revolution, the climatic changes in earth were due to natural causes like the variations in the availability of sunlight in the earth and also due to the volcanic activities. But, it is found that the influence of these natural causes is very small compared to the severe global warming caused due to human activities. Fossil fuels burnt by us release 100 times and more carbon dioxide to the atmosphere than the carbon dioxide released by volcanic emission. Variations in the intensity of sunlight do affect the solar energy reaching on the earth; however Sun cannot be blamed for the acute situation of present global warming.

Greenhouse Effect

About 30 percent of the sunlight falling on earth is reflected back into space by clouds, ice and other reflective surfaces. The other 70 percent is absorbed by the land, oceans, and the atmosphere. The land and oceans in turn radiate the heat into the atmosphere, known as infrared radiation, which is absorbed by the carbon dioxide, nitrous oxide, methane and water vapour present in the atmosphere. After absorbing the heat, these greenhouse gases emit heat energy keeping the planet warmer, suitable for life on earth. This natural greenhouse effect keeps the average surface temperature of earth at a comfortable 15 degree centigrade; otherwise it would be very cool at about -18 degree centigrade.

Carbon dioxide (CO2): But, due to the industrial revolution and change in lifestyle, we are increasing the concentration of greenhouse gases, especially carbon dioxide, in the atmosphere to a huge amount, mostly by burning an enormous amount of fossil fuels and also by deforestation. More carbon dioxide results in more absorption of the infrared radiation emitted from the surface, and hence higher surface temperature of the earth; because the energy coming in through the atmosphere is greater than the energy going out.

Nitrous oxide (N2O): Nitrous oxide is more dangerous because it absorbs more energy than carbon dioxide, at about 270 times as much, and hence needs more attention. Nitrous oxide is released to the atmosphere by the Nitrogen fertilizers used in crops and by combustion.

Methane: Methane gas absorbs and emits 20 times more heat than carbon dioxide. Methane gas is produced by extracting from coal, from bacteria in rice paddies, by decomposition of garbage, from natural gas, etc.

Water Vapour: Water vapour is available in the atmosphere in large quantity and is responsible for about two-thirds of greenhouse warming. Water on earth surface, after absorbing heat from sun and the surroundings, evaporates and rises higher to the atmosphere. The temperature of the surrounding air becomes lower and the water vapour in the atmosphere releases heat to the surrounding air. Thus the vapour comes back to its liquid form and falls down due to earth’s gravitational force. The whole cycle repeats.

GW2

Effects of Global Warming

In addition to the warming caused by greenhouse gases, there will be significant impacts on the planet that will make life miserable. Some of these changes are already occurring.

Weather Change: Global warming produces increasing number of hot days with intense heat waves occurring frequently. Climatic pattern will completely change producing severe floods, droughts and storms. Surface temperature of oceans and seas will be warmer that will cause hurricanes of higher intensity. The rhythm of seasons will change with untimely occurrence and periodic variations of seasonal events like rainfall and droughts. Due to extreme weather and the shifts of seasons, millions of people will suffer from infectious diseases.

Melting of Glaciers and Ice: Melting of glaciers and ice on the surface of earth will quicken the global warming process because less solar energy will be reflected away from earth. Melting of glaciers will result in rise of sea levels causing frequent flood calamities in low coastal areas. If the sea level rise will become 10 meters or more, many of the coastal areas would completely disappear.

Melting of Polar Ice:  Antarctica at the South Pole contains 90 percent of the world’s ice, which if melted completely would raise the sea levels around the world by 61 meters, but no such danger of melting is envisaged because its average temperature is -37 degree Celsius. But, in the North Pole, the ice melted due to warming floats over the Arctic Ocean. Melting of this floating ice will not raise the sea level significantly.  But, due to absence of ice, the area absorbs more sunlight and dissipates more heat energy to earth surface accelerating warming. There is also the danger of melting the abundance of ice covering in Greenland that would raise sea levels by 7 meters.

Ecosystem Change: Ecosystems are very delicate and interconnected with the plants and animals that live within the intricacies of particular climate zones. Any minute change in ecosystems can kill several species and those depending on them. Shifting of seasons results in mismatching life cycles, affecting the bee-plant relationship, and limiting the survival and reproduction of plants. Earlier emergence of insects, earlier flowering of trees and earlier egg-laying in birds are some of the observed ecological changes. Most of the species and plants that are the fittest may survive the shift in seasons, but many of them would become extinct.

Due to increase in temperature in the growing season, plants and crops dry out due to shortage of water. Wild fire swallows deep forests and converts them to a barren land. Scientists have estimated 3 to 5 percent drop in the production of crops corresponding 1 degree Fahrenheit temperature rise.

Diseases: Global warming will affect people very badly, especially those living in poorer countries that do not have sufficient financial resources to deal with their problems. Heat strokes and other heat related diseases will take the lives of thousands. Fresh water will be a scarce item for the long periods of summer, and the extreme droughts will increase famine and malnutrition. Several infectious diseases like malaria and dengue fever will spread around the globe that will take several lives.

What Can We Do?

We cannot prevent the global warming completely, but we can take some precautions to reduce its effects.

  • Walk or use bikes, if possible, instead of using cars.
  • If you cannot avoid using car, ensure that your vehicle emits less harmful gases.
  • Turn lights and electrical appliances off when not in use. Use Compact Fluorescent Lamps instead of incandescent bulbs. Use fans and avoid air conditioner and heaters. Thus save electricity. Remember that by burning of fossil fuels, the power plants generate electricity as well as greenhouse gases.
  • Use non-fossil fuel energy sources to produce electricity. Instead of fossil fuel power plants we should develop more number of hydro-electric power plants, solar power plants, wind power, hydrogen engines, etc.
  • Plant trees. Trees absorb carbon dioxide and release oxygen.
  • Do not fell trees or destroy forests. Trees are our protectors, so we should protect them.Deforestation is one of the major causes of global warming.
  • Recycle garbage to avoid development of landfill and release of methane gas.
  • Create awareness among people all over the world regarding global warming and its far-reaching consequences.

Conclusion

Global warming is a real problem that is happening and the main culprit is carbon dioxide that we release into the atmosphere by burning fossil fuels to generate electricity, run our vehicles, run our industries and light our homes. We cannot avoid electricity, our vehicle, our industries and of course our favourite home. But we can do something to reduce the aggressive emissions through advanced technology to increase energy efficiency; we can shift to more renewable source of energy; and we can protect our forests rather than destroying them. We should be prepared with the knowledge and resources to withstand the effects of global warming. Let us be ready to face the reality, so that we will not stand embarrassed in front of the questions of the future generations about a sustainable world. 

Image source: http://commons.wikimedia.org/wiki/File:Citemene.JPG


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