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.
Administracija Informacije o Energiji je procijenila da su se u 2006. godini primarni izvori energije sastojali od nafte 36.8%, ugljena 26.6%, prirodnog plina 22.9%, što rezultira 86% postotnim udjelom fosilnih goriva u primarnoj svjetskoj proizvodnji energije.