ABSTRACT
Energy is consumed either as fuels in liquid, gaseous, or solid forms or as electricity, in the modern global economy. There are four basic forms of energy: kinetic energy, gravitational energy, electrical energy, and nuclear energy. Eventually, the global economy has fundamentally transformed and human civilization have fully based on renewable energies. Nuclear energy and most renewable energies are mainly used to generate electricity rather than to make liquid fuels. Oil currently accounts for about one-third of the world's primary energy consumption and one-half of the final energy consumption. Oil is essential for transportation, modern agriculture, and chemical industries. Currently, fossil fuels account for about 94 percent of the world's total energy consumption. Nuclear and renewable energies account for 6 percent. Fossil fuels are nonrenewable resources and the consumption of fossil fuels results in greenhouse gas emissions threatening to bring about global ecological catastrophes.
