Its more likely higher dollar causing lower copper imo.
http://classic.tradingcharts.com/chart/CP/W
http://classic.tradingcharts.com/chart/US/W
Copper choppy lateral since ’73 to ’04, China or Economies booming did NOTHING to raise copper for decades. TPTB are losing control. You won’t hear this on their media. Flat copper for decades thru booms or busts. They never talk about the dollar. Oil did not go up or drop on its own. Lower Dollar makes things get go too high = over production and less consumption, or dollar to high causes lower prices = less production and more consumption.
Its called unstable currency value, or a drunk steering left and right, or children moving levers every which way in a nuclear power plant.