According to the USGS how much total copper was contained in the world as of 2018

Answer 1

As of 2018, the U.S. Geological Survey (USGS) estimated that there were approximately 870 million metric tons of copper reserves worldwide. This includes both identified and inferred resources. It’s important to check the latest USGS publications or reports for the most current statistics, as these numbers can change with new discoveries and assessments.