Global warming is the phenomenon of a gradual overall increase in the average temperature of the Earth’s atmosphere due to the accumulation of certain gases. The Earth’s atmosphere is made up of major gases namely, oxygen and nitrogen, and minor constituents such as water vapour and carbon dioxide. These gases play a crucial role in moderating the Earth’s temperature. This is because these gases are relatively transparent to incoming visible light from the sun, but absorb the heat radiation given off by the ground and objects exposed to the sun. As a result they produce a heating of the atmosphere by what is known as the “green-house effect”. Without the “green-house gases” in the atmosphere and the resulting green-house effect’ the Earth’s average surface temperature would be as low as -20 degree Celsius.

            But what is of concern today is the ever increasing level of carbon dioxide and certain other greenhouse gases in the atmosphere during the past several decades. Estimates suggest that by the middle of the 21^st century the Earth may be 2 degree to 9 degree Celsius warmer. This warming will result in large scale inundation of coastal areas as a result of rising sea levels due to the melting of polar ice caps. Widespread climatic changes are also forecast due to this global warming.Already the world has started feeling the heat of  human Errors and this one just gets added to the list

Genetic engineering is a technique of manipulating the DNA in cells to endow an organism with qualities it did not naturally possess. The technique is also called gene manipulation. It entails a number of steps the first of which is the constitution of DNA segment from nucleic acid molecules in a test tube. The length of DNA so made is inserted into a virus or some other suitable vector that can serve as a molecular ferry to carry it into the host organism. The crucial factor here is ability of the inserted DNA molecule to express itself and also to multiply. Bacteria and even higher animals may be genetically engineered to produce foreign proteins of interest by inserting a copy or multiple copies of the gene coding for the protein into them. Several important products of medical use such as insulin and the human growth hormone are now being produced commercially using genetically engineered bacteria. The crucial factor here is ability of the inserted DNA molecule to express itself and also to multiply. ‘Tracy’, a genetically engineered sheep produces the pharmaceutically important protein called Alpha-1 antitrypsin in her milk. Genetic engineering may be used to boost growth, alter resistance to factors such as drugs, heat, cold and salinity in both animals and plants.

Gene therapy is a new and as yet largely experimental branch of medicine that incorporates techniques of genetic engineering to correct inherited disorders or inborn errors of metabolism. The idea of curing a genetic disorder by repairing or replacing a faulty gene or gene product (protein) first occurred to Dr. W. French Anderson now recognized as the father of gene therapy.

            In gene therapy the flawed gene is identified and copies of its normal version are produced in the laboratory by cloning. Then suitable host cells are selected from the patient’s body and genetic engineering is used to transfer copies of the normal version of the gene into it. The doctored cells are then returned to the body by injection.The idea of curing a genetic disorder by repairing or replacing a faulty gene or gene product (protein) first occurred to Dr. W. French Anderson now recognized as the father of gene therapy. The introduced genes are incorporated into the chromosomes of the patient’s cells and propagate with each cell division. Since the introduced genes work normally and produce the protein that was previously either absent or malformed, the error is corrected in the victim who gets cured of the symptom. However, since gene therapy is not approved for genetic manipulation of the germ or reproductive cells, the cure cannot be passed on to future generations of the cured victims.