OverviewFossil fuelsEarth minerals and metal oresNuclear fuelsLand surfaceRenewable resourcesEconomic modelsSee also
Natural resources such as coal, petroleum(crude oil) and natural gas take thousands of years to form naturally and cannot be replaced as fast as they are being consumed. Eventually it is considered that fossil-based resources will become too costly to harvest and humanity will need to shift its reliance to other sources of energy such as solar or wind power, see renewable energy. An alternative hypothesis is that carbon based fuel is virtually inexhaustible in human terms, if o