Global warming is the current increase in temperature of the Earth’s surface (both land and water) as well as its atmosphere. Average temperatures around the world have risen by 0.75ºC (1.4ºF) over the last 100 years. About two thirds of this increase has occurred since 1975. Carbon dioxide, methane, Chlorofluoro Carbon, nitrous oxides are the green house gases warming the earth’s surface. So it is also called green house effect. The CO2 is the most important of the green house gases contributing to 50% of global warming. The burning of fossil fuel, and other biomass, deforestation result in CO2. In the past, when the Earth experienced increases in temperature it was the result of natural causes but today it is being caused by human activities.
Global warming adversely affects agriculture, horticulture and eco system. Reduced rainfall, higher temperature and increased pest/weed growth hamper farming. Threats to health arise due to increase in disease carrying vectors such as mosquitoes resulting in malaria, dengue fever, encephalitis and yellow fever.
An increase in the global average surface air temperature of such magnitude will bring about alarming changes in rainfall patterns and other climatic conditions, resulting in serious ecological disequilibrium.