Zinc is a Sustainable Resource
Natural Reserves of Zinc
The world is naturally abundant in zinc. It is estimated that the first mile of the earth’s crust under land contains 224,000,000 million tonnes of zinc. There are a further 15 million tonnes of zinc in the seabed, and each cubic mile of seawater is estimated to contain one tonne of zinc. Such estimates, however, fail to consider whether or not it is economic, or environmentally acceptable, to exploit these resources.
Reserves of zinc – like those of any natural resource – are not a fixed amount stored in nature. Reserves are determined by geology and the interaction of economics, technology and politics. The term “reserves” denotes only what has been mapped and measured today and what can be mined, economically, using current technology. Zinc reserves have increased significantly since the 1950s, as large new ore bodies have been discovered in many areas of the world. The sustainability of zinc ore supplies cannot therefore be judged simply by extrapolating the combined mine life of today’s zinc mines.
An example of this can be illustrated by comparing United States Geological Survey (USGS) data on zinc reserves. In 1994, USGS reported that world zinc reserves were 140,000,000 tonnes, but by 2005, despite 11 additional years of consumption, the USGS reported world zinc reserves of 220,000,000 tonnes, a 57% increase over 1994 levels.
During the 1990s, commodity prices were relatively stable at low levels, causing production to stagnate and limiting the creation of exploration and mining operations. In recent years, prices have become more volatile, with large increases followed by rapid declines. Exploration and production have likewise risen and stabilized or declined.
The mining industry is also investing in new technologies and techniques to increase the efficiency of zinc extraction and processing. Recycling of zinc products by the industry also provides an opportunity to help conserve the natural zinc reserves even more. The level of recycling increases each year, in step with the progress in zinc production and recycling technologies.
For more information, please visit http://www.zinc.org/sustainability.