Natural gas is an increasingly important source of the world's energy. Estimating future supplies of this valuable commodity is an important economic and strategic endeavor. However, world gas supply forecasting has proved difficult because its exploration, transportation, and customer bases depend so heavily on fluctuating economic factors. Gas production fluctuations from several countries were affected by the relationship between gas and oil industries, economic burdens, and governmental-policy implementations. This work presents innovative approaches for analyzing and forecasting natural gas supply for individual countries and the world. These new methods include the multicyclic modeling, artificial intelligence technology, and time-series analysis. Most industrialized countries are depleting their gas resources much faster than are developing countries. Fuel switching and gas dependence by industrial and commercial sectors and production decline of crude oil in these countries are among the reasons for the high depletion rate. Russia and major Arabian Gulf countries will be major sources of world gas supply representing about 62% of world's future recoverable conventional gas.