Resource Extraction

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Resource Extraction

Introduction

Resource extraction refers to activities that involve withdrawing materials from the natural environment. Logging is one example of resource extraction. If not done in a sustainable manner, logging extracts trees and their removal causes other changes that can result in soil and nutrient removal from the logged area. Even if it is accomplished sustainably, logging changes an environment.

Mining that involves the creation of an open-air pit is another example of resource extraction. Other examples include the oil sands project (the extraction of oil-laden sediment from regions of the Canadian province of Alberta), and the more conventional processes of oil recovery.

In contrast to logging, where trees (a renewable resource) can be replanted and nurtured to permit lumbering for a long time, oil extraction is permanent. Fossil fuels that have taken millions of years to develop cannot be renewed. Indeed, agencies including the U.S. Geological Survey (USGS) have forecast that the amount of recoverable oil will peak and then begin to decline before the year 2100.

Efforts to minimize the environmental damage of resource extraction can be challenging, as the economic benefits of activities such as logging, mining, and the oil sands are considerable. For example, some critics of the oil sands project in Alberta have decried the minimal restrictions placed on greenhouse gas emissions by the provincial and federal governments.

Historical Background and Scientific Foundations

Resource extraction activities have been practiced for thousands of years. Archaeological evidence indicates that 6,000 years ago Egyptians mined by building a fire against a rock face and then dousing the fire with cold water to split the rock. The use of gunpowder to blast away rock dates back to 1617 in Germany. Open-pit mining is a more recent development, since sophisticated machinery is needed to expose the subsurface material and to haul it away.

Logging dates back to the use of land to raise crops and livestock. In North America, this began in the 1820s on the East Coast and near the end of that century as settlement from Europe expanded westward.

Clear-cutting—the type of logging in which nearly all or all trees in a given area are removed—is a resource extractive practice on several levels. Complete removal of the forest canopy exposes the ground to more sunlight, which can dry the soil. Also, competition for nutrients becomes more intense as fast-growing shrubs and grasses grow and grazing animals move into the area.

On another level, removing trees can increase the surface movement of water, which can increase erosion. Along with directly extracting the soil, erosion removes more nutrients from the environment. Flow of soil into streams, rivers, and lakes occurs more easily, which can stimulate the increased use of oxygen. As a result, the water can become too oxygen-poor to support fish and plant life.

Operations such as open pit mining and the Alberta tar sands project extensively disrupt the surface. In the case of the tar sands, efforts are made to repair the damage. However, the result will not be the same as the environment prior to the extraction of the oil-laden sediment. More importantly, both operations generate toxic compounds that can escape to the environment. The runoff water from mines and the leftover material can be extremely acidic and can contain concentrations of heavy metals that are lethal to many forms of life.

Impacts and Issues

Clear-cutting can be accomplished faster and less expensively than a tree-by-tree survey and harvesting of a forest. However, the consequences of the clear-cut approach to logging includes erosion, reduced diversity of life in the logged region, and loss of the forest canopy—all of which can be environmentally destructive.

The loss of trees reduces the ability of a forest to retain carbon dioxide. As a result, more of this potent greenhouse gas is released into the atmosphere; the increased warming of the atmosphere since the time of the Industrial Revolution, which began in the late-eighteenth century, has been conclusively linked to increased atmospheric levels of greenhouse gases such as carbon dioxide. Thus, resource extraction not only has a local effect, but influences the global climate.

The Brazilian rain forest, for example, which makes up 30% of the total acreage of rain forest on the planet, is being logged at a rate that if continued could eliminate the forest entirely by 2050.

The oil sands also damage the global environment due to the generation of carbon dioxide in the processing of the extracted oil. Although the Canadian government has committed to reducing Canada’s greenhouse-gas emissions by 20% by 2020, the oil sands project has been given approval for expansion, and the resulting increased production of greenhouse gases could make the reduction target difficult to achieve.

WORDS TO KNOW

EROSION: The wearing away of the soil or rock over time.

RENEWABLE RESOURCE: Any resource that is renewed or replaced fairly rapidly (on human historical time-scales) by natural or managed processes.

RUNOFF: Water that falls as precipitation and then runs over the surface of the land rather than sinking into the ground.

SILVICULTURE: Management of the development, composition, and long-term health of a forest ecosystem. The objective is often to allow logging of the forest over many years.