This document discusses sustainable energy resources and environmental degradation. It defines key terms related to renewable and non-renewable energy sources. It also describes various energy sources such as fossil fuels like coal, oil and natural gas, as well as renewable sources like hydropower, solar, wind, geothermal and biomass. It notes that while fossil fuels are cheap and easy to develop, they pollute the environment. Renewable resources are more sustainable but can be costly to implement. The document also discusses inequalities in energy consumption between wealthy and poor nations.