Fossil fuels burnt to achieve humanistic objectives raise the extent of such greenhouse gases in the atmosphere as carbon dioxide, methane, nitrous oxide and chlorofluorocarbons. Besides, rapid deforestation has also contributed to the 30% increase in the extent of carbon dioxide in the atmosphere over the last two centuries which is even expected to double in amount by the end of 21st century should the current practices continue. (Hamburg et al, 1997). Methane, second to carbon dioxide in amount in the atmosphere is generated from rice cultivation and decaying landfills. Human agricultural and industrial activities have drastically increased the amounts of greenhouse gases in the atmosphere which has led to an increase in temperature and ozone depletion. Studies have been conducted on various levels to estimate the human contribution to the change in climate and scientists are of the view that had humans not been involved in the game, Earth’s surface temperature would not have even risen by 0.5C where it is actually foreseen to rise by 3.5C till 2100 since 1991. (Hamburg et al, 1997). Research suggests that humans are chiefly responsible for changes in climate.
Hamburg, SP, Harris, N, Jaeger, J, Karl, TR, McFarland, M, Mitchell, JFB, Oppenheimer, M, Santer, BD, Schneider, S, Trenberth, KE and Wigley, TML 1997. “Common Questions about Climate Change”. United Nations Environment Programme - World Meteorological Organization, viewed 5 September, 2010,