Using a geology-based assessment methodology, the U.S. Geological Survey estimated a mean of 3,500 million metric tons (Mt) of undiscovered copper among 225 tracts around the world. Annual U.S. copper consumption is 2 Mt; global consumption is 20 Mt. The USGS assessed undiscovered copper in two deposit types that account for about 80 percent of the world's copper supply. Results of the assessment are provided by deposit type for 11 regions. Approximately 50 percent of the global total occurs in South America, South Central Asia and Indochina, and North America combined.