Effect of human activites on environment

  Green House Effect

        The process of heating up of earth atmosphere due to excess concentration of green house gases . Most of the long wavelength radiations from sun are absorbed by green house gases like water 

vapor, carbon dioxide, nitrous oxide and methane .

 These greenhouse gases act as a thermal blanket around the globe, raising the earth’s temperature beyond the equivalent calculated temperature (this accounts for the 33°C).The surface of earth is 33°C higher than what is predicted due to green house effect.As a result increasing the water levels in oceans thus it engulf small islands with low altitude thus there beautiful islands disappear causing loss of habitat for endemic species and thus affecting environment. Increase in the green house gas is result of human activites for satisfying his needs.Emission from automobiles that run on fossile fuel and emission from factories are the major contributor to the Greeen House Effect .Let us now remmenber what Mahatma Gandhi  "Earth provides enough to satisfy everyman’s need but not for anybody’s greed".

Methods to control the pollution

•        Clean coal technology to burn coal more efficiently and will lesser toxic pollutants emitted.

•        Flue gas desulphurisation: removes the acid rain-producing sulphur oxides from the flue gas

•        Yet combustion of coal invariably leads to CO₂ emissions and global warming

Global warming and Ozone –Depletion impacts of CFCs

Fully halogenated CFCs have long atmospheric lifetimes,contain relatively large amounts of chlorine, and can absorb strongly within the 7 to 13 micro meter atmospheric window.Therefore, they have considerable potential for global warming and ozone depletion.They are 15000 times potent than carbon dioxide when compared to carbon dioxide

Perspectives on Global Atmospheric change

Policy areas that deserve immediate attention are

1.Adopting an energy policy that encourage reduction of carbon emission

(a) Increase the energy efficiency

(b) Use Renewable energy technologies

(Solar thermal systems, wind – electric systems etc)

2. Developing International agreements that control production and emission of damaging trace gases

(a) Reduction of CFC

(b) Reduction of CO₂ emission

3. Supporting efforts to halt deforestation and encourage reforestation

(a) Financial assistance for developing    countries from developed countries

(b) Environmental tax

(c) Urban reforestation

Radioactive Waste Disposal

•        Radioactive wastes can remain a concern for at least 10,000 to 1,000,000 years. Some nucleotides can have half lives of millions of years.

•        The wastes may remain dangerous for several half lives.

•        The possible health impacts for such periods should be examined critically.

•        Practical studies only consider up to 100 years as far as effective planning and cost evaluations are concerned.

•        Long term behavior of radioactive wastes remains a subject for ongoing research projects.