Increased emissions due to increased use of fossil fuels. Most of our energy input is non renewable. Can not be remade or re grown at a scale comparable to its consumption. Coal, oil, natural gas and uranium are non renewable. Windows receive sunlight which can heat the house. Trees provide shade which provide cooling in the summer. Solar panels collect solar energy and use the energy to heat/cool the house. Liquid is heat using energy collected from solar panel. Energy from the sun warms the earth"s surface unevenly, which causes air masses to flow in the atmosphere (tendency to come to equilibrium) movement of these air masses as wind. Wind power converts the movement of wind into electric energy fastest growing energy source in the world. Predicted to supply 10% of the world and 20% of the us by 2030. windfarms are groupings of wind turbines in rural areas. Pros: efficient, quick constructed, no emissions, moderate cost, cheap energy.