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https://www.environment.co.za/mining-2/effects-of-mining.html
Coal mining, the first step in the dirty lifecycle of coal, causes deforestation and releases toxic amounts of minerals and heavy metals into the soil and water. The effects of mining coal persists for years after coal is removed.
Dear Readers, please refer to this latest article regarding the serious effects of Acid Mine Drainage on the environment and human lives in South Africa. This Harvard report was just recently released in October, 2016 and is extremely in depth on the issues of the serious effects of mining on the environment and human health.
Bad mining practices can ignite coal fires, which can burn for decades, release fly ash and smoke laden with greenhouse gasses and toxic chemicals. Furthermore mining releases coal mine methane, a greenhouse gas 20 times more powerful than carbon dioxide. Coal dust inhalation causes black lung disease among miners and those who live nearby, and mine accidents kill thousands every year. Coal mining displaces whole communities, forced off their land by expanding mines, coal fires, subsidence and contaminated water supplies.
There are two widely used ways of mining: strip mining and underground mining.
Strip mining (also known as open cast, mountaintop or surface mining) involves scraping away earth and rocks to get to coal buried near the surface. In many cases, mountains are literally blasted apart to reach thin coal seams within, leaving permanent scars on the landscape as a result.
Strip mining accounts for about 40 percent of the world’s coal mines but in some countries, such as Australia, open cast mines make up 80 percent of mines. Even though it’s highly destructive, industry often prefers strip mining as it requires less labour and yields more coal than underground mining.
The result of all this is barren land that stays contaminated long after a coal mine shuts down.
Although many countries require reclamation plans for coal mining sites, undoing all the environmental damages to water supplies, destroyed habitats, and poor air quality is a long and problematic task. This land disturbance is on a vast scale. In the US, between 1930 and 2000, coal mining altered about 2.4 million hectares [5.9 million acres] of natural landscape, most of it originally forest. Attempts to re-seed land destroyed by coal mining is difficult because the mining process has so thoroughly damaged the soil. For example, in Montana, replanting projects had a success rate of only 20-30 percent, while in some places in Colorado only 10 percent of oak aspen seedlings that were planted survived.
In China, coal mining has degraded the quality of land of an estimated 3.2 million hectares, according to a 2004 estimate. The overall restoration rate (the ratio of reclaimed land area to the total degraded land area) of mine wasteland was only about 10–12 percent.
The majority of the world’s coal is obtained through underground mines. While underground mining, which allows coal companies to extract deeper deposits of coal, is viewed as less destructive than strip mining, the effects of mining widespread damage to the environment. In room-and-pillar mines, columns of coal are left to support the ground above during the initial mining process, then they are often taken out and the mine is left to collapse, which is known as subsidence. In longwall mines, mechanical shearers strip the coal from the mines. Support structures that enable the shearers’ access to the mine are eventually removed, and the mine collapses. It is these effects of mining that nobody sees but are the most troubling of all.
Coal mine methane, less prevalent in the atmosphere than CO2, but 20 times as powerful as a greenhouse gas, forms during the geological formation of coal, and is released during the coal mining process. Most coal mine methane come from underground mines. While this methane is often captured and used as town fuel, industrial fuel, chemical feedstock and vehicle fuel, it’s very rare that it all gets used.[vii] Methane is also used in power generation projects. However, despite big investment in research, only about 50 such projects exist worldwide.
Worldwide emissions are expected to increase by 20 percent in the next 12 years.
Coal fires – burning or smouldering coal seams, coal storage piles or coal waste piles – are a significant environmental problem in many countries, including China, Russia, the US, Indonesia, Australia and South Africa. Underground coal fires can burn for centuries, filling the atmosphere with smoke laden with carbon-monoxide (CO), carbon-dioxide (CO2), methane (CH4), sulphur dioxide (SO2), nitrous oxides (NOx) and other greenhouse or toxic gases – as well as fly ash from vents and fissures.
Other effects of coal fires include rising surface temperatures and contamination of groundwater, soil and air.
Although coal fires can be caused by thunderstorm lightning, and forest or peat fires, they are often caused by mining accidents and improper mining techniques. In Indonesia, the same fires that are used to clear large tracts of rainforest have ignited over 300 coal fires since the 1980s.
China has the world’s most coal fires, while India accounts for the world’s greatest concentration. In China, between 15 and 20 million tons of coal burn uncontrollably each year, accounting for between 0.1 percent and 1 percent of the world’s human-induced CO2 emissions, (Although coal fires are significant, emissions from power plants are far higher.)
Acid mine drainage is created when water mixes with coal and other rocks unearthed during mining, taking on toxic levels of minerals and heavy metals. This toxic water leaks out of abandoned mines to contaminate groundwater, streams, soil, plants, animals and humans. As a result an orange colour can blanket the river, estuary or sea bed killing plants and making surface water unusable as drinking water. Acid Mine Drainage is one of the biggest effects of mining being felt around the world, especially in South Africa where the problem has been ignored for over 100 years. A well known organisation in South Africa, the Federation for a Sustainable Environment, spearheaded by Ms Mariette Liefferink has been fighting the issue of the effects of mining and Acid Mine Drainage with government and mining companies for 2 decades.
Sources of acid mine drainage can remain active for decades or centuries after a mine closes.