Globally, buildings are responsible for approximately 40% of the total world annual energy consumption. Most of this energy is for the provision of lighting, heating, cooling, and air conditioning. Increasing awareness of the environmental impact of CO2, NOx, and CFCs emissions triggered a renewed interest in environmental-friendly cooling and heating technologies. Under the 1997 Montreal Protocol, governments agreed to phase out chemicals used as refrigerants that have the potential to destroy stratospheric ozone. It was therefore considered desirable to reduce energy consumption and decrease the rate of depletion of world energy reserves and pollution of the environment. This article discusses a comprehensive review of energy sources, environment, and sustainable development. This includes all the renewable energy technologies, energy efficiency systems, energy conservation scenarios, energy savings, and other mitigation measures necessary to reduce climate change.