No one should be shocked that the positive correlation between the world’s two leading industrial commodities has broken down over the past month. Oil has surged 15 per cent on supply concerns while copper is off 9 per cent from its record London high of $10,190 a tonne, in part due to fears of what more expensive crude might do to the world economy. But developments in the Middle Kingdom, not just the Middle East, are affecting copper prices.

China, by far the world’s single largest copper consumer, already outstrips the appetite of what some decades ago was called the “industrialised world”. China’s demand for the red metal overtook North America and western Europe combined in 2008 and analysts at Credit Suisse forecast it will be double their consumption by 2013, soaking up a third of all supply.

Given its projected needs for copper-intensive infrastructure, forecasts seem consistent with economic growth expectations. Even so, the copper market may be expecting an overly smooth and upward-sloping trajectory in the medium term. Chinese imports of all industrial commodities took a tumble last month due to the Lunar New Year, but copper’s fall seems especially sharp. Shipments were the lowest since January 2009, when prices were a third today’s level.