Scientists think copper ores will last much longer, at least until 2070. Give two possible reasons for the change in their estimate.
Copper is a metal that is actively being searched for. If a new source of copper is found then that increases the known reserves and therefore how long until it runs out. Another reason for re-estimating the reserves is to do with economic factors, mainly the price of copper ore. We will have a number of smaller, currently uneconomic deposits of copper yet to be exploited because the cost of extraction is more than any money that would be made, so as reserves dwindle and prices rise, these deposits get used aswell.
1. Copper is one of the most widely recycled of all metals; approximately one-third of all copper consumed worldwide is recycled. Recycled copper and its alloys can be remelted and used directly or further reprocessed to refined copper without losing any of the metal's chemical or physical properties. - 2. About 590 million tons of copper has been discovered and about 750 million tons of copper is estimated to remain as undiscovered porphyry copper deposits. ============== I hope this is helpful.
