Global production of aluminium and copper have steadily increased over recent decades, while lead production has been fairly stable. Recycling has also been increasing, reducing the growth rate of primary production of aluminium and copper, and reducing primary production of lead. Despite depletion of the richest ores and a shift to less concentrated ores, advances in mining technologies have lead to generally declining, though fluctuating, metal prices. Supplies of these metals are sustainable for the foreseeable future. Sustainable development issues relate rather to energy consumption, revenue reductions for exporting countries, and health and environmental impacts.