The phenomenon commonly known as greenhouse effect occurs due to emission of certain gaseous pollutants in the air which after the heating of the atmosphere, causes the average global temperature to rise. The effect produced by certain gases, such as carbon dioxide or water vapour, that cause a warming of the earth’s atmosphere by absorption of infra-red radiation. The atmosphere protects us by serving as a light scattering and heat mediating blanket. A large portion’ of heat emitted from the earth is absorbed by the atmosphere and is, in effect, conserved, with the result that the surface of the Earth is warmer than it otherwise would be. In simple words, this warming is called the greenhouse effect, by analogy with the ability of a greenhouse to keep its inside warmer than the outside during the day time.
The atmospheric concentration of these gases has relatively inccreased since the advent of the industrial era. There has emerged a growing consensus in the scientific community that the anthropogenic greenhouse gas emission of carbon dioxide, nitrous oxide, CFCs methane and low level ozone threatens to disrupt human societies and natural ecosystems.
The developed world accounted for nearly 80 per cent of the total industrial carbon dioxide emission of carbon dioxide, nitrous oxide, CFCs methane and low level ozone threatens to disrupt human societies and natural ecosystems.
The developed world accounted for nearly 80 per cent of the total industrial carbon dioxide emissions and the rest of 20 per cent originated in the developing world. On the other hands. 98 per cent CFCs are produced in developed and two per cent in developing world. With the current trend emissions a WHO study speculates that the combined effects of the six most important greenhouse gases could by the early years of 2030s commit the global warming equivalent to doubling of pre-industrial concentrations of carbon dioxide. The scientists are of the opinion that the earth will be hotter by 2 to 4 c by the middle of the 21st century.
The atmospheric blanket keeps the earth habitable and protects living forms from fatal radiations of the sun. The atmosphere intercepts solar radiation, reflecting a third of it while the rest is absorbed by the atmosphere, ocean, ice, land and biosphere. The energy absorbed balanced by the outgoing radiation from the atmosphere and the earth. This vital balance will be altered with infringement of greenhouse effect resulting an overall rise in the average global temperature.
Among the most dramatic consequences of the greenhouse climatic disruption is an unprecedented rise in global sea levels to the extent of 8 to 25.5 inches by the end of the century if gas emissions continue at the present rate Melting of polar ice and glaciers, thermal expansion of seas would cause world-wide coastal flooding and rise in sea level will result in submergence of many coastal areas. It will not only effect the ecological balance but will be a threat to the people and economy of the countries like Bangladesh, Netherlands, as well as to many coastal and island countries. In fact, the impact of world-wide climatic disruption could have hazardous consequences for the survival of the planet both biologically and economically. The Montreal Protocol was a step in this direction but an overall solution requires a combined efforts of all nations and international bodies. Apart from this, scientific and technological research in this field can also reduce the risk to a great extent, provided it reaches all nations specially to the developing nations.