There is concern within some factions of the energy industry about an approaching energy crisis. In the case of hydrocarbons, eventually there will be a maximum peak in global production. The question is if it will occur sooner or later, and if it will happen because of depletion or because of substitution to other energy sources - perhaps unconventional or non-fossil. This does not preclude hydrocarbon shortages that might still occur due to temporary factors such as political instability and lack of investment. Although the past is not always an indication of the future, an analysis of global market shares (i.e. the mix) for solids, liquids and gases from the year 1850 to 2005, leads to a model that permits a reasonable forecast of the global possibilities of future methane and hydrogen economies. It is concluded that if there is a supply problem in the future it will not be the result of depletion, but rather the failure of society to invest in the research and development of technology needed to provide conventional and unconventional hydrocarbons, as well as alternatives such as hydrogen, on a timely basis. Proper development of these resources will lead to sustainable and efficient global economic growth. Copyright 2006, Society of Petroleum Engineers.