POPULATION AND LANDUSE
ining is the world's fifth largest industry. It has provided the raw materials for the construction and commodities of the modern world: tower blocks and airplanes, televisions and toothpaste. Much of it is dominated by transnational corporations serving global markets through the intense exploitation of mineral-rich land.
Humans have always used materials dug from the ground, whether stone and clay to make shelter, precious metals for adornment and ceremonial purposes, or more workaday minerals for tools. Their use became a marker for our technological progress through the iron and bronze ages, and throughout history the search for minerals helped drive the expansion of civilizations into new territory. The Romans first went to Britain to extract tin, while gold and silver drew Europeans to the New World and the British, French and Belgians to Africa. The desire to extract minerals also drove railroad construction across the United States, Canada and Siberia. [Add]
While bulky and more widely available materials tend to be extracted locally, largely reflecting local population levels, rarer materials have always had an international market. Two thirds of European investment in Africa before the 1930s went into mining, until the sector made up half of the continent's exports. Gold and diamonds underpin the (ill-distributed) wealth of South Africa.
Rising demand for materials has created increasingly global industries, in which local demand and demographics are largely irrelevant to levels of exploitation. Today, one of the front lines of exploration for minerals is in the Asian islands of Borneo and New Guinea, which contain the world's largest copper and gold mines, but few of the world's people.
Traded globally but produced in intense local mining areas, mineral extraction often reflects the negative social and ecological impact of global economic forces. Rising demand has driven technologists to find ways of extracting the more valuable materials from low-grade ores, with a resulting dramatic increase in the disturbance of the land. The copper industry increased production 22-fold in the 20th century, partly by extracting metal from a 0.5 percent ore, compared with a 3 percent limit at the century's start. The industry's 99.5 percent discard of mined ore is matched by wastes of upwards of 60 percent in the mining of iron, 70 percent for manganese, and 99.75, 99.95 and 99.99 percent respectively for tungsten, zinc and gold. Canada produces 60 times more mining waste than urban refuse . The 20th century also saw the rapid growth of new extraction industries -- bauxite for aluminum, uranium for nuclear weapons and power, and petrochemicals for plastics.
In consequence, over the past century mining has removed an estimated 100 million people from their land and destroyed forests and farmland, either directly for extraction or to accommodate the waste. The extraction and refining of ores requires the use of toxic substances such as cyanide and mercury, which are often allowed to pollute land and river systems. It is estimated that a ton of mercury is released into the Amazon environment for every ton of gold extracted , poisoning local wildlife including fish eaten by humans. [Add]
Acid emissions from Russia's metal smelting have destroyed vegetation over hundreds of square kilometers of the Arctic Kola peninsula. The Sudbury nickel smelter in Ontario did similar damage in Canada in the 1970s and 1980s. The South African mining industry, which employs some 800 000 people and generates half the country's foreign exchange, is also responsible for around a million tons of sulfur emissions a year. It is one of Africa's largest sources of acid pollution . [Add]
While lending itself to large-scale industrial enterprise, mining for minerals also employs millions of artisan miners across the world. In Latin America an estimated 1 million artisan miners are at work, exploiting gold in particular. Mining "rushes", whether involving artisans or corporations, frequently cause social conflict, often over pollution. Amazon gold miners have clashed with the Yanomami in the Amazon. Mines at Bougainville and Grasberg in New Guinea have caused civil insurrection. Such disputes are often exacerbated when governments appear to side with mining companies against the interests of the local communities. [Add]
Some refining and smelting processes require large amounts of energy. Many of the world's major hydroelectric dams have been constructed to supply cheap electricity for smelting aluminum. The Hoover dam on the River Colorado in the United States is one such example. Another is the Akosombo dam in Ghana. Built in the 1960s to provide hydropower to smelt bauxite for a United States company, Akosombo flooded more than 5 percent of the country and displaced 80 000 people to create the largest artificial lake on Earth. [Add]
Since the 1960s, growing environmental awareness coupled with real shortage of some strategic metals has encouraged a new trend towards recycling. Glass, aluminum, gold and iron are all recycled on a large scale. New materials have also reduced the pressure on some mineral resources -- glass fibers are replacing copper in cable systems, for instance. Resource managers dream of "closing the loop", with 100-percent recycling. Even industries making complex products are moving towards a recycling strategy -- for instance the European automobile manufacturing industry, which is dedicated to making the majority of car parts recycleable.
But there may be practical limits to this approach. Recycling is not an absolute virtue. Some analysts argue that the environmental cost is sometimes greater than the cost of starting from scratch with new raw materials. In most instances, efforts to reduce the use of raw materials and energy, and to avoid the unnecessary purchase of new items such as automobiles and office equipment, should be the preferred strategy.
The impact of recycling on overall mineral exploitation has so far been small. Production of metals and minerals has more than doubled since the early 1960s, while petrochemicals production has risen more than fivefold . [Add]