**3.3 Environmental impacts**

Renewable energy projects have also contributed in improving environmental impacts such as reduction of carbon dioxide gas, awakening community about the climate change. The study observed very small impacts on the people living in a particular area, tourism, cost of energy supply, and educational impacts. Significant impacts were observed in improvement of life standard, social bonds creation, and community development. They also observed that the renewable energy projects are complex to install and are local environmental and condition sensitive. Their forecasting, execution, and planning require more consideration and knowledge as compared to other projects [4]. The two main aspects of environment are air and water pollution, normally created by the discharged water from houses, industries, and polluted rain, and discharge of used oils and liquids contains poisonous chemicals and heavy metals like mercury, lead, etc. Along with water pollution, natural resources can be maintained and greenhouse effect and air pollution can be mitigated by the proper usage of renewable energy sources [23] as shown in **Table 4**. Carbon dioxide emission with the generation of electric power using different energy resources is given in **Figure 2**.

Various greenhouse gases in atmosphere is being increased by humankind by doing many economic activities. The role of greenhouse gases and current situation are given in **Table 5**.
