Global warming refers to the rising average temperature of the earth’s atmosphere and oceans, which started to increase in the late 19th century and is projected to keep going up. If we go for the scenario of 20th century in relation to global warming, since the early period of this century, Earth’s average surface temperature has increased by about 1.4 F i.e. 0.8oC. This finding is, with about two thirds of the increase occurring since 1980. Warming of the climate system is unequivocal and scientists are more than ninety percent certain that most of it is caused by increasing concentrations of green house gases produced by human activities such as deforestation and burning fossil fuels. The national science academies have also recognized these findings. An increase in global temperature will cause sea levels to rise and will change the amount and pattern of precipitation and a probable expansion of subtropical deserts. If global mean temperature increase by 4oC above pre-industrial levels, the limits for adaptation for natural systems will largely be exceeded. Hence the ecosystem services upon which human livelihoods depend would not be preserved. The effect of global warming in India vary from submergence of low lying islands and coastal lands to the melting of glaciers in the Indian Himalayas, threatening the volumetric flow rate of many of the most important rivers of the India. Global warming shows some deadliest effects. Polar ice caps melting due to global warming will raise sea levels. Ice caps will throw the global ecosystem out of balance. Temperature rises and changing landscapes will endanger several species of animals. If Ice caps melt, the only reflector is the ocean; darker colours absorb sunlight, further warming the Earth. Anthropogenic global warming has economic consequences. Due to global warming, there is increased probability and intensity of droughts and heat waves. As the temperature of oceans rises, so will the probability of more frequent and stronger hurricanes. In future, towns of India like Mumbai, Chennai etc. may be covered with water due to global warming as such towns are situated on the bank of sea. As a consequence of this, the population of the country will decrease.