Many researchers have found that non-renewable energy resources, such as oil and natural gas, are nearing depletion due to increasing human use. The most valuable non-renewable source of energy is fossil fuels. Its price affects the entire global economy due to production instability and lack of consistant oil pricing. By comparison, renewable energy resources are able to support human energy needs without depletion. Although renewable energy resources are currently unable to completely displace all of our non-renewable energy use, many scientists are making advancements in renewable energy technology. It can be hoped that in time, science will enable the complete substitution of non-renewable energy resources for fossil fuels (McKinney and Schoch, 2003).
Fossil fuels are created by the decomposition of living organisms. These can be separated into three types: coal, natural gas and oil. Coal is a solid fossil fuel created by the decomposition of land vegetation. When compared with other fossil fuels, coal is quite abundant and easily recovered in many locations. Many developing countries depend on coal for energy because they cannot afford other fossil fuels. India and China are the main consumers of coal.
Natural gas is a vaporous fossil fuel that is abundant, useful and relatively clean compared to other fossil fuels. It is formed from the remains of marine microorganisms. Natural gas is used in many developed countries. Oil, a liquid fossil fuel, is the most widely used and valuable fossil fuel. It is also created from the remains of marine microorganisms deposited on the sea floor. Crude oil is refined and used for fuel in cars and other forms of transportation. Oil is not available everywhere on earth, but is found only in specific areas. Consequently, it is a powerful energy source that influences the world economy through fluctuations in price, supply and demand (BBC Weather Centre, n.d.).
Energy is extracted through the process of burning fossil fuel (combustion) and then converted to other forms of the energy such as heat and electricity. Carbon (C) and Hydrogen (H) react during the combustion process to form Carbon Dioxide (CO2). Heat is released during this process. The release of CO2 and heat into the atmosphere is a major contributor to the Greenhouse effect and global climate change, both of which are now an increasing concern throughout the world.