Green energy is energy which is generated without any negative effect on the environment. Traditional energy sources like fossil fuels, produce greenhouse gases that are the primary cause of global warming or climate change. Sources of green energy are solar, wind, geothermal, and hydro energy. These are alternative sources of energy that make little or no contribution to climate change and renewable energy with nearly zero pollution. Nowadays nuclear energy has become a green energy source because their technology produces much less waste than oil and coal. Green energy means energy derived from renewable, zero-emissions sources, as well as energy saved through energy efficiency measures. Most of our electrical energy comes from power stations that use fossil fuels like oil and coal. The power stations use the fossil fuels to produce electricity which in turn releases the greenhouse gas, including methane and carbon dioxide. Hence, they are the worst sources of energy. The greenhouse gases increase the Earth's atmospheric temperature, leading to climatic changes. The air and water pollution produced by natural gas and coal plants causes breathing problems, neurological damage, heart attacks, and cancer. So, generating electricity from renewable energy rather than fossil fuels saves the human health and the environment.