This chapter examines the science of the greenhouse effect and related global warming. It also talks about the relation to fossil fuel emissions; global climate change and global warming, including public policy and public opinion; and mitigation strategies related to carbon sequestration. The fundamental science of the greenhouse effect has to do with the selective transmission and absorption of energy depending on the wavelength of the source. The greenhouse gas (GHG) effect on the potential increase in warming of the atmosphere is carbon dioxide. This is due to the large quantities of carbon dioxide emitted in fossil fuel combustion and its relatively long residence time in the atmosphere. The most comprehensive mitigation strategy is to move the energy economy from one based on fossil fuels to one based on energy efficiency and renewables. Another mitigation strategy is to increase the use of natural gas.