The second half of the twentieth century emerged with two important concepts of the economic world. In the start of the second half, economists, developmentalists, etc., introduced the idea of “development”, while; latter it was replaced by a more meaningful and attractive term “sustainable development”. Sustainable development is defined as “balancing the fulfillment of human needs with the protection of the natural environment so that these needs can be met not only in the present, but also in the indefinite future” [Wikipedia (2007)]. Or “Sustainable development means that pattern of development that permits future generations to live at least as well as the current generation” [Todaro and Smith (2005)], eighth edition]. The field of sustainable development can be conceptually broken into four constituent parts: environmental sustainability, economic sustainability, social sustainability and political sustainability. Although, the word sustainable development is very vast and deep, but the main emphasis of our study will be on environmental sustainability.