Renewable energies such as solar, wind, hydroelectric, biomass and geothermal can help address climate change by reducing greenhouse gas emissions from fossil fuels like oil, gas and coal. These alternative energies are natural and unlimited sources that do not contaminate while fossil fuels are limited and produce large amounts of carbon dioxide and other pollutants. Countries around the world have begun investing heavily in renewable energies to transition to a more sustainable energy system that protects the environment.