Energy demand is increasing rapidly in the world due to a lot of factors like industrialization, population growth. The primary energy source that fulfils this demand is conventional energy sources such as petroleum oil and coal. With the burning of lots of fossil fuels, substantial environmental pollution happens widely in the world, and the consequences of these can be catastrophic. One of the effects is climate changes that the world is experiencing in the present due to Green Gas Emissions (GHG). Using Renewable energy(RE) to replace fossil fuel burning is a trending solution for this matter. This paper focuses on the renewable types, the role of Renewable energy in reducing GHG Emission, how much potential in Sri Lanka as a developing country to reduce GHG emission and the problems facing when implementing RE in developing countries.