This marks 100 years of continuous weather records for Phoenix. The assistance given by Mr. Robert S. Ingram, former Meteorologist in Charge, National Weather Service Office, Phoenix, Arizona, Mr. Paul C. Kangieser, former NOAA Climatologist for Arizona, and other staff members is gratefully acknowledged.
Most liquid fuels in widespread use are derived from the fossilized remains of dead plants and animals by exposure to heat and pressure in the Earth's crust. However, there are several types, such as hydrogen fuel (for automotive uses), ethanol, jet fuel and biodiesel which are all categorized as a liquid fuel.
The three fossil fuel types are coal, petroleum and natural gas. It was estimated by the Energy Information Administration that in 2006 primary sources of energy consisted of petroleum 36.8%, coal 26.6%, natural gas 22.9%, amounting to an 86% share for fossil fuels in primary energy production in the world.