Green revolution is the introduction of industrialized agriculture to the developing world in the mid- and late- 20th century and it allowed the production of greater quantity and quality of food. This industrialization became necessary because people realized that farmers could not keep cultivating more land to increase crop output, than, agricultural scientists devised methods and technologies to increase crop output per unit area of existing cultivated land.
This new agriculture uses synthetic fertilizers and chemical pesticides; special types of grains that are more resistant to wind and diseases and produces high yields -transgenics; and heavy equipment powered by fossil fuels.
These developments had mixed effects on the environment. The use of already-cultivated land reduced pressure to convert additional natural land for new cultivation. As a matter of fact, between 1961 and 2003, food production rose 150%, population rose 100%, and the area converted for agriculture increased only 10%. Therefore, the green revolution prevented some degree of deforestation and habitat conversion when many countries were experiencing their fastest population growth rates.
However, there also are many negative sides that we must pay attention to:
The intensive application of water, fossil fuel, innorganic fertilizers, and synthetic pesticides worsened pollution, and soil problems like erosion, salinization, and desertification;
As monocultures made planting and harvesting more efficient, the increased output reduced biodiversity, because many fewer wild organisms are able to live in monocultures than in native habitats or amid tratitional small-scale polycultures;
When all plants in a field are genetically similar as in monoculture, all are equally susceptible to viral diseases, fungal pathogens, or insect pests that can spread quickly from plant to plant. Therefore monocultures bring some risks of cataqstrophic failure;
Many yields are declining in some regions because of the decline in soil quality from the heavy use of fertilizers, pesticides, and irrigation.
Green revolution and population
It is really important to understand the reason why the green revolution happened.
The transfer of technology to the developing world that marked the green revolution began in the 1940s, when US agricultural scientist Norman Borlaug introduced Mexico’s farmers to a specially bred type of wheat that produced large seed heads, was short in stature to resist wind, was resistant to diseases, and produced high yields. Within two decades of planting and harvesting this specially bred crop, Mexico tripled its wheat production and began exporting wheat. After this huge success, the wheat was taken to India and Pakistan, and soon, many developing countries were doubling, tripling, or quadrupling their crop yields using selectively bred strains of wheat, rice and corn, among others.
In the 1960s, India’s population, for instance, was skyrocketing and it’s traditional agriculture was not producing enough food to support the growth. By adopting green revolution agriculture, India sidestepped mass starvation. In the years since intensifying its agriculture, India has added several hundred million more people and continues to suffer widespread poverty and hunger.
Still, because of the huge problems brought by the green revolution, we can’t think of it as the solution of our food supplies problem. In fact, Borlaug called his green revolution methods “a temporary success in man’s war against hunger and deprivation”.
Healthy soil is vital for agriculture, for forestry, and for the functioning of Earth’s natural systems. As a renewable resource, once depleted of it’s productivity, it may renew itself over a very long and slow time. We’ll reduce it’s ability to support life if we have careless or uninformed practices.
Soil Characteristics
Soil characteristics vary from place to place, they’re defined basically by temperature and amount of rain. Soil in the Amazonian rainforest, in northern Brazil is less productive than the soil of temperate grassland in Kansas. This difference is due to the amount of rain that falls in the Amazon, because the water leaches minerals and nutrients from topsoil; also the warm temperatures speed the decomposition of leaf litter and the uptake of nutrients by plants, in a way that humus remain small in the thin topsoil layer.
Kansas prairie, in the other hand, has a lower rainfall, which means that the leaching is reduced and the nutrients remain within reach of plants’ roots. Plants return nutrients to the topsoil when they die, maintaining its fertility. The thick and rich topsoil of temperate grasslands can be farmed repeatedly with minimal loss of fertility if farming techniques like no-till and reduced tillage are used.
Therefore, most of the world’s soils are not ideal for agriculture, but that does not stop our world’s population to grow 80 milion people a year, which means that we are pressing lands into cultivation that are unsuitable for farming, which causes considerable damage to soil. Thw world loses anually 5-7 milion ha (12-17 milion ac), about the size of West Virginia.
Some consequences of careless use of the soil are:
Erosion – removal of material from one place and its transport toward another by the action of wind or water. The arrival of eroded material at a new location is called deposition.Erosion and deposition are natural processes that help to create soil. Productive soils are produced by deposit of eroded sediment in river valleys and deltas by flowing water;
Even though erosion is a natural process, it becomes a problem for ecosystems and agriculture because it occurs more quickly than soil is formed and tends to remove the topsoil, which is the most valuable soil layer for living things. People have made fertile lands more vulnerable to erosion by overcultivating fields through poor planning or excessive tilling; overgrazing rangelands with more livestock than the land can support; clearing forests on steep slopes or with large clear-cuts.
Soil is protected from wind and water by grasslands, forests, and other plant communities. Vegetation breaks the wind and slows water flow. Plant roots hold soil in place and take up water. The removal of these plants accelerates erosion.
Overgrazilng – when sheep, goats, cattle, or other livestock graze on the open range, they feed on grasses. If the livestock population do not exceed a range’s carrying capacity and it does not consume grasses faster than they can be replaced, grazing may be sustainable. However, when too many animals eat too much of the plant cover, the plant regrowth is impeded and the replacement of biomass is prevented.
Overgrazing worsen damage to soils, natural communities, and the land’s productivity for grazing. All this happens because when livestock remove too much plant cover, soil is exposed and made vulnerable to erosion. Like I’ve said before, erosion makes it difficult for vegetation to regrow, in a way that the cycle of lack of cover provoking more erosion is perpetuated.
Another consequence is non-native weedy plants invasion. Plants that are less palatable to livestock may invade denuded soils and outcompete native vegetation in the new, modified environment. Overgrazing also compact soils and alter its structure. Compacted soil is hard for water to infiltrate, to be aerated, and for plants’ roots to expand or to conduct cellular respiration.
Overgrazing is a greater cause of desertification. Humans keep a total of 3,4 billion cattle, sheep, and goats, and rangeland declaration is estimated to cost $23,3 billion per year.
Clearing forests – is the cut of all trees in ane area. Clear-cutting is cost-efficient in the short term, however, has severe impacts on forest ecosystems. It may mimic natural disturbance events like fires, tornadoes or windstorms, and destroy or displace ecological communities, provoke soil erosion, and sunlight penetration to ground level might change microclimatic conditions, in a way that new types of plants replace those of the native forests;
Desertification – is the loss of more than 10% of productivity due to erosion, soil compaction, forest removal, overgrazing, drought, salinization, climate change, depletion of water sources, and other factores. Severe desertification can expand desert areas and create new ones in once-fertile regions. This has occured in areas of the Middle East, that have been farmed and grazed for long periods of time.
Desertification affects one-third of the planet’s land area and costs tens of billions of dollars a year for people in over 100 countries. A 2007 United Nations report estimated that desertification, worsened by climate change, could displace 50 milion people in 10 years. China loses $6.5 bilion annually. Desertification causes gigantic dust storms called dust bowl.
Dust bowl – erosion of millions of tons of topsoil by strong winds. It’s caused by the removal of native grasses and the break down of soil structures. They might travel up to 2,000 km (1,250 mi). In the 19th and early 20th centuries, homesteading settlers spread through Oklahoma, Texas, Kansas, New Mexico, and Colorado. Farmers grew wheat and ranchers grazed thousands of cattle, both on unsuitable land. In 1930, a drought exarcerbated the ongoing impacts and the dust storms begun. Some areas lost 10 cm (4 in) of topsoil in a few years.
These problems made the US government, the state and local government increase support for research into soil conservation measures. The Soil Conservation Service (SCS) was created and started to work with farmers to develop conservation plans for individual farms. The SCS teams include soil scientists, forestry experts, engineers, economists, and biologists. Nowadays, the SCS is called Natural Resources Conservation Service, and it serves as a model for similar efforts elsewhere;
Salinization – buildup of salt in surface soil layers. It is more common in arid areas where precipitation is minimal and evaportion rates are high. This happens because of irrigation. Irrigation have allowed dry and unproductive regions into fertile farmland. However, overirrigation saturates soil with water in a way that waterlogging, when the water table rises to the point that water bathes plant roots, might occur. This is bad because it deprives the plant roots of access to gases and suffocates them.
Salinization occurs because if the area is to arid, the evaporation of water from the topsoil may pull water rich in dissolved salts upward through the soil from lower horizons. When the water evaporates at the surface, its salts precipitate, turning the soil surface white.
Salinization inhibits production of one-fifth of all irrigated cropland globally, and cost more than $11 billion a year. The best way to prevent it is avoid planting crops that require a great deal of water in areas that are prone to the problem. A second way is to irrigate with water low in salt content, since the irrigation water often contains some dissolved salt. And a third way is to irrigate efficiently, supplying no more water than the crop requires. These mesures minimize the amount of water that evaporates and hence the amount of salt that accumulates in the topsoil;
Fertilizers – like overirrigation might result on salinization, overapplying fertilizers can cause chemical damage to soil with severe pollution problems. Plants require nitrogen, phosphorous and potassium to grow, altogether with other nutrients. These nutrients are removed from soil as the plants grow, and leaching likewise removes nutrients. If agricultural soils come to contain too few nutrients, crop yields decline, that’s when fertilizers are used. There are two main types of fertilizers, inorganic and organic. Organic fertilizers can provide some benefits that inorganic cannot. The proper use of these compounds improves soil structure, helps to retain nutrient and increase the water retaining capacity; erosion is prevented.
Agriculture is the practice of raising crops and livestock for human use and consumption. It always and it’s impacts on global environment have increased when Green Revolution began, around 1945. It’s environmental effects include:
Alterations of the Earth’s hydrologic cycle;
Increased levels of atmospheric greenhouse gases;
Decreased biodiversity;
Accelerated rates of soil erosion;
Rapid spread of eutrophication in freshwater and marine ecosystems.
The human population has grown and so have the amount of land and resources given to agriculture, which currently covers 38% of Earth’s land surface. Most of our food and fiber are obtained from cropland, land used to raise plants for human use; and rangeland or pasture, which is land used for grazing livestock. The large-scale mechanization and fossil fuel combustion enabled farmers to replace horses and oxen with faster and more powerful means of working with crops and livestock. This was the agricultural revolution, and it allowed the increase of food production by intensifying irrigation; introduction of synthetic fertilizers; and the use of chemical pesticides reduced competition from weeds and herbivory by crop pests.
Modern industrialized agriculture enabled us to feed more people at a very high ecological price. Industrial agriculture can remove forests; destroy wetlands; turn grasslands to deserts; diminish biodiversity; encourage invasive species; pollute soil; air and water with toxic chemicals; and allow fertile soil to be blown and washed away.
Even though we have more food to feed more people, political obstacles and inefficiencies in distribution makes 850 milion people in developing countries without enough to eat. In adition, although human population growth has sloewd, we can still expect our numbers to swell to 9 bilion by the middle of this century. Therefore, the kind of word we’ll live in then will depend on choices make now, and knowing how to make food supply sustainable , maintaining healthy soil, water and biodiversity is one of them. Agricultural scientists and policymakers pursue a goal of food security, the guarantee of an adequate and reliable food supply available to all people at all times.
There are some farming techniques that can reduce the impacts of conventional cultivation on soils. Those are:
Crop rotation – the type of crop grown in a field is alternated from one season or year to the next. This method can return nutrients to the soil, break cycles of disease associated with continous cropping, minimize erosion that might come from letting fielts lie fallow, and reduce insect pests, because if an insect is adapted to feed and lay eggs on one crop, planting a different type of crop will leave its offspring with nothing to eat. The crop rotation works if one of the rotated crops are legumes, because they have specialized bacteria on their roots, responsible for fixing nitrogen, revitalizing soil that the previous crop had partially depleated of nutrients;
Contour farming - cultivation on slopes, even though water might erode the soil more easily. Farmers plow furrows sideways across a hillside, perpendicular to its slope and follow the natural contour of the land to help prevent formation of gullies;
Terracing – the most effective method for preventing erosion, terracing consists on making levels platforms to contain water from irrigation and precipitation. It transforms slopes into series of steps like a staircase, enabling farmers to cultivate hilly land without losing huge amounts of soil to water erosion;
Intercropping – also minimize erosion because it consist on planting different types of crops in alternating bands or other spatially mixed arrangements. Intercropping provides more ground cover and reduces vulnerability to insects and disease;
Shelterbelts or windbreaks- used to reduce erosion from wind. Consists on the plantation of rows of trees or other tall, perenial plant along the edges or fields to slow the wind;
No-till farming – a tractor pulls a “no-till drill” that cuts furrows through the topsoil and crop residue, drops seeds into the furrow, and closes it over the seeds. A dose of fertilizer might be added to the soil along with the seed.
Among many aspects, environmental health is the examination of the impacts of human-made chemicals on wildlife and people. It’s study and practice allows us to understand the environmental factors that influence human health and quality of life. People who work with it seek to prevent adverse effects on human health and ecological systems.
There are many different types of environmental health threat, or hazard, around us. Some of those are risks that we cannot avoid, however, there is also some amount of risk that can be avoided by taking precautions. Environmental health consists of taking steps to minimize the impacts of hazards and the risks of encoutering them. Here I’m going to talk a little bit about some of them, but focuse more on the chemical ones.
Physical hazards - are the natural hazard previously mentioned on the last post. Therefore, they are processes that occur naturally like earthquakes, volcanic eruptions, fires, floods, blizzards, landslides, hurricanes, and droughts, but they also include ongoing natural phenomena, like ultraviolet (UV) radiation from sunlight, which can cause skin cancer, cataracts, and immune suppression in case of excessive exposure.
Practices like increase our vulnerability to some physical hazards:
Channelizing rivers makes flooding more likely in some areas while preventing flooding in others. For more information about this, click here.
The risk over these practices can be reduced by improving our forestry and flood control practices; by choosing not to build in areas prone to floods, landslides, fires, and coastal waves. For hazards like exposure to UV light, the risk can be reduced by using clothing and sunscreen to shield our skin from intense sunlight.
Biological hazards- result from ecological interaction among organisms. They consist on bacterial or virus infection or other pathogeny. This is infectious disease, and they are also called communicable or transmissible disease. Infectious diseases like malaria, cholera, tuberculosis, and influenza are considered environmental health hazards. Like the other two types of hazards, it’s impossible to avoid risks from biological agents, however, steps can be taken to reduce the likelihood of infection.
Cultural orlifestyle hazards- result from the place we live, our socioeconomic status, occupation, or behavioral choices. Choosing to smoke cigarettes or living or working with people who do, increases our risk of lung cancer. Choosing to smoke is a personal behavioral decision, but exposure to secondhand smoke may not be under one’s control. The same thing can be said for drug use, diet and nutrition, crime and mode of transportation. Advocates of environmental justice argue that such health factors as living in proximity to toxic waste sites or working unprotected with pesticides might be correlated with socioeconomic deprivation.
Chemical hazards – include the many synthetic chemicals produced by our society like disinfectants, pesticides and the compounds that contribute to reproductive problems on animals. Chemicals produced naturally by organisms can also be hazardous.
Despite diseases like cancer, heart disease, and respiratory disorders have genetic bases, they are also influenced by environmental factors. Asthma, for instance, is influenced by genes, but also by environmental conditions. As a matter of fact, pollutants from fossil fuels combustion makes it worse. Children raised on farms suffer less asthma than those raised in cities.
Malnutrition can foster many different illnesses, just like poverty and poor hygiene. Lifestyle choices can affect risks of acquiring som noninfectious diseases, just like smoking can lead to lung cancer and lack of exercise, to heart disease. Infectious diseases are responsible for 26%, nearly 15 milion deaths, that occur worldwide per year. Some pathogenic microbes attack us directly, whereas other times infection occurs through a vector, which is an organism that transfers the pathogen to the host. When it comes to infectious diseases there is a gap between the number of deaths in developed nations and the developing countries; differences in hygiene conditions and access to medicine makes infectious diseases be responsible for almost half of all deaths in developings, while there are very few deaths in developed nations.
Even though public health efforts have lessened the impact of infectious disease in developed nations, some cases like the West Nile Virus, acquired immunodeficiency syndrome (AIDS), avian flu and influenza. Other diseases like tuberculosis and malaria are evolving resistance to antibiotics. There are also some tropical diseases like malaria, dengue, cholera and yellow fever that might expand into the temperade zone with global climate change. Also, habitat alteration can affect the abundance, distribution, and movement of certain disease vectors.
There are some cases in which chemicals are used to fight diseases, even though they’re also hazardous to our health. This happens in Africa, where the pesticide DDT is used to kill the mosquitos that transmit malaria, because they’re considered to be a health threat greater than DDT.
Curiosity:
It was only on the 60s that people began to learn about the risks of exposure to pesticides. The publication of Rachel Carson’s 1962 book, Silent Spring, was the key event that brought the pesticide dichlorodiphenyl-tricholoroethane (DDT) to public’s attention.
Synthetic chemicals are widely present in our environment, in fact, many of them have found their way into soil, air and water. A 2002 study by the US Geological Survey found that 80% of the US streams contain at least trace amounts of 82 wastewater contaminants, including antibiotics, detergents, drugs, steroids, plasticizers, disinfectants, solvents and perfumes, among other substances. The pesticides used to kill insects and weeds on farms, lawns, and golf courses are some of our most widespread synthetic chemicals. Because of this huge exposure, we carry traces of numerous industrial chemicals in our bodies.
Since not all synthetic chemicals pose health risks, and few are known as toxicants, we shouldn’t necessarily be alarmed. However, among the roughly 100,000 synthetic chemicals on the market today, few have been tested for harmful effects; therefore, we just do not know what are the effects, if any, so much different chemicals might cause to our organism.
Toxicants are not evenly distributed in the environment, and they move about in specific ways. Water, for example, carries toxicants from large areas of land and concentrates them in small volumes of surface water. Those chemicals that can persist in soil can leach down into groundwater and contaminate drinking water supplies. Many chemicals are soluble in water and enter organism’s tissues through drinking or absorption. That’s the main reason why aquatic animals like fish, frogs and stream invertebrates are effective indicators of pollution. Whenever scientists find low concentrations of pesticides exerting harm on frogs, fish, and invertebrates, they view this as a warning that people could be next. Toxicants might cause reproductive problems on animals and humans.
The contaminants that wash into streams and rivers flow and seep into the water we drink and drift through the air we breathe.
The substances that can be transported by air makes the toxicological effect occur far from the site of direct chemical use. Airbone transport of pesticides is also called pesticide drift. This problem can be seen in the Central Valley of California, where irrigation, fertilizers and pesticides are used intensively. Dust particles containing pesticide residue and are transported by the wind for long distance and affected four species of frog in the mountains of Sierra Nevada.
Toxic agents may degrade quickly and become harmless, or may remain unaltered and persist for months, years or decades. The rate at the chemicals degradation depends on factors like temperatura, moisture and sun exposure, and how these factors interact with the chemistry of the toxicant. Those toxicans that persist in the environment have the greatest potential to harm organisms over long periods of time. In fact people are concerned about DDT and PCBs because of their long persistence time.
There are natural toxicants that are also unhealthy and may cause us harm. However, scientists are still debating how much risk natural toxicants pose.
In this post I’m not going to talk about the consequences of the climate change, but how hazards impacts can be reduced or mitigated, and also what we do to make them worse.
Even though they have many causes, in a broad way, hazards can termed into:
Natural or physical- caused by a natural process. Include obvious hazards like earthquakes, landslides, fires, droughts, blizzards, volcanic eruptions, tornadoes, hurricanes and flooding;
Man-made – created by human negligence, error, or system failure, which includes an array of possibilities that goes from immediate hazards such as dam failure or shipping accidents and global warming, even though it is not believed by scientists called skeptics.
Besides the geological hazards such as earthquakes, volcanoes, peole face other types of natural hazards that result from conditions in the hydrosphere, atmosphere, or biosphere. Flooding, caused by heavy rains, ravage low-lying areas near rivers and streams; coastal erosion eat away at beaches; wildfire threaten life and property in fire-prone areas; tornadoes and hurricanes can cause extensive damage and loss of life.
Even though tose are “natural hazards”, the magnitude of their impacts upon us depend on choices we make. We can make those impacts be worse in various ways:
Population growth makes people live in areas susceptible to natural disasters;
Many people choose to live in areas that seem to be attractive but are also prone to hazards. Coastlines are vulnerable to tsunamis and erosion by storms; mountainous areas may feature volcanoes and mass-wasting events;
Engineer landscapes can increase the frequency or severity of natural hazards. Damming and diking rivers to control floods can lead to floodings; suppressing natural wildfire puts forests at risk of larger fires; mining practices like clear cutting on slopes can induce mass wasting, speed runoff, compact soil and change drainage patterns;
Earth’s climate changed by emitting greenhouse gases alter patterns of precipitation, increasing risks of drought, fire, flooding, and mudslides locally and regionally. Rising sea levels induced by global warming increase coastal erosion. Some research suggests that warming ocean temperatures may increase the power and duration of hurricanes.
We can also mitigate or reduce the hazards impacts by:
Using technology, engineering, and policy, informed by a solid understanding of geology and ecology. There are building earthquake-resistant structures;
Designing early warning systems for tsunamis and volcanoes;
Conserving coastal forests, reefs and salt marshes protect against tsunamis and coastal erosion;
Better forestry and mining practices can help prevent landslides;
Zoning regulations, building codes, and insurance incentives that discourage development in areas prone to landslides, floods, fires and storm surges can keep us out of harm’s way and decrease taxpayer expense cleaning up after natural disasters;
Like I’ve said on the last post, there are many mining methods and their use is defined by the nature of the mineral deposit: Strip mining: Commonly used for coal, sand, gravel and oil sands. This method is used when the resources occur in shallow horizontal deposits near the surface. Consists on the removal of the soil and rocks layers -also called overburden, until the resources’ exposure. Afterwards, the resource is extracted by machinery and each strip is refilled with the overburden that had been removed.
The environmental impacts of strip mining are:
Destruction of natural communities over large areas;
Acid drainage, a process in which chemical runoff rans into waterways. Occurs when sulfide minerals in newly exposed rock surfaces react with oxygen and rainwater to produce sulfuric acid. The sulfuric acid runs off and leaches metals from the rocks. Acid drainage is actually a natural phenomenon, however, mining accelerates it by exposing many new rock surfaces at once;
Water polution by sulfuric acid;
Subsurface mining:Commonly used for zinc, lead, nickel, tin, gold, copper, diamonds, phosphate, salt, coal and uranium. Is used when the resources occurs in concentrated pockets deep underground. The most dangerous form of mining, consists on deep excavation. Networks of tunnels are dug or blasted out to follow deposits of the mineral, removed by the miners. Subsurface mining can be mind-boggling, and the world’s deepest mines extend nearly 4 km (2.5 mí) undergroud, are found in South Africa.
The environmental impacts of the subsurface mining are:
Acid drainage ;
Toxic leachate can make it’s way down into groundwater;
Abandoned mine sites can continue polluting groundwater long after mining has ceased;
Subsurface mining often progresses below the water table, so water must be constantly pumped out of the mine in order to prevent flooding. When a mine is abandoned, the pumping ceases, and water floods the mine;
Poisoned water might find an outlet, usually into streams and rivers where, in changing the pH level, the ambient life is killed;
The social impacts of subsurface mining are:
One of society’s most dangerous occupations because if a mine collapse, there will be a massive sinking of the land above, like happened in Utah, in August 7th, 2008, resulting on the death of six miners;
Injury and death from dynamite blasts and collapsed tunnels;
Toxic fumes and coal dust can be fatal because they can lead to respiratory diseases, including fatal black lung disease.
Open pit mining: Commonly used for copper, iron, gold, diamonds and coal. Whenever the mineral to be exploited is gravel, sand, clay, and stone like limestone, granite, marble and slate, the pits are called quarries. Is used when the mineral is spread widely and evenly throughout a rock formation, or when the earth is unsuitable for tunneling. This process consists on digging a gigantic hole and removing the desired ore, along with waste rock that surrounds the ore. The pit is expanded until the resource runs out or becomes unprofitable; than the pit is abandoned. The world’s largest open pit mine is the Binghan Canyon Mine, near Salt Lake City, Utah, with 4km (2.5 mi) across and 1.2 km (o.75 mi) deep. The Binghan is also the world’s largest human made hole in the ground.
The open pits needs to be large because of the volume of waste rock needed to be removed in order to extract relatively small amounts of ore, which contains still smaller traces of mineral.
The environmental impacts of open pit mining are:
Considerable degree of habitat loss and aesthetic degradation;
Acid drainage, therefore chemical contamination;
Abandoned pits generally fill up with groundwater because they’re far more deeper than water table. This groundwater soon becomes toxic as water and oxygen reacts with sulfides left in ore, in a way that sulfuric acid is produced.
Acidic water from the pit can harm wildlife, percolate into groundwater supplies and spread through the region’s environment;
Curiosity:
Even though developed nations have regulations requiring waste heaps to be capped with clay, soil, and vegetation once the mines are closed, many dumps will leach acid for hundreds of thousand of years. The largest Superfund toxic waste cleanup site in the US is the Berkeley Pit. Closed in 1982, nowadays the huge hole is filled with groundwater and became so acidic (pH of 2.5) and concentrated with toxic metals that microbiologists discovered new species of microbes in the water. The impressive thing is that the harsh conditions were so rare in nature that scientists had never before encountered microbes adapted to them.
Placer mining: Commonly used for gold and gems, this method is used on riverbed deposits, whenever metals and gems accumulate, having been displaced from elsewhere and carried along by flowing water. In this process the miners sift through material in modern or ancient riverbed deposits, normally using running water to separate lightweight mud and gravel from heavier minerals of value. This method is used by Congo’s coltan miners. Today’s African miners are like the miners who ventured to California in the Gold Rush of 1849 and later to Alaska in the Klondike Gold Rush, areas where placer mining is still practiced.
The environmental impacts of placer mining are:
Debris are washed into streams, in a way that they become uninhabitable for fish and other life for many miles downstream;
The stream banks are disturbed, causing erosion and ecological harm to important riparian plant communities.
Mountaintop removal: Commonly used for coal in Appalachian Mountains. This method is used especially because it is economically efficient for companies to extract coal, in a way that it has expanded in recent years. This practise consists on the removal of the mountain’s fores by clear cut, than the topsoil is removed, and rocks are blasted away to expose the coal. Repeated cycles of blasting and extraction may remove hundreds of vertical feet of mountaintop. The environmental impacts of placer mining on stream and river ecosystems pale in comparison to the devastation wrought by mountaintop removal, no wonder why there are some environmental organizations like ILove Mountains and Appalachian Voices agains this type of mining.
Nowadays, there is a lot of pressure from civils, environmental organizations and governamental departments to forbit the mountaintop removal. Yesterday (3/31/09), a federal judge issued an injunction blocking the U.S. Army Corps of Engineers from authorizing new mountaintop removal mining operations through its streamlined Nationwide Permit procedure.
Waste rocks dumped into valleys and streams degradates or destroys immense areas of habitat and pollutes and clogs streams and rivers;
Intensified erosion because of the slopes deforestation and valleys filled with debris;
Mudslides become frequent and flash floods ravage the lower valleys;
Some critics argue that valley fillig violates the Clean Water Act.
The social impacts of mountaintop removal are:
People living near the sites can be heartbreaking. Blasts from mines crack house foundations and wells;
Floods tear through properties;
Coal dust causes respiratory ailments;
Contaminated water unleashes a variety of health problems;
Loose rock tumbles down into yards and homes;
Overloaded coal trucks speed down once-peaceful rural roads;
Landowners are pressured to sell their land to coal companies;
Coal industry touts the importance of mining jobs for the Appalachian economy. However, the efficiency of mountaintop removal means that fewer workers are needed. Therefore, in recent years, even though coal extraction has risen, employment has declined;
Because of the environmental impacts of mining, governments of the US, Canada, and other nations now require that mining companies restore, or “reclaim”, vegetation atop surface-mined sites following mining. However, there are still many nations like Congo that don’t have any regulation at al. In the US, the Surface Mining Control and Reclamation Act mandates restoration efforts, and requires companies to post bonds to cover reclamation before mining is approved. To restore a site, they have to remove buildings and other structures, replace overburden and fill in shafts, and replante the area with vegetation.
About replanted areas, some things still need to be reminded:
Even restored sites might still suffer from mining impacts -such as soil and water impact from acid drainage for many years.
Restored sites do not generally regain the natural biotic communities that were present before mining. That happens because the fast-growing grass anchor restoration efforts helping to control erosion, however, it doesn’t do anything to speed the establishment of forests, wetlands, or other complex natural communities;
The grass used often outcompete slower growing native plants in the acidic, compacted, nutrient-poor soils that usually result from mining;
Many vital symbioses that maintain ecosystems are eliminated by mining and are very difficult to restore. Specialized relationship between plants and fungi and plants and insects are examples.
It is still very important to remember that minerals are nonrenewable, they’re in finite supply, because they don’t regenerate fast enoughto provide us a new supply once we have mined all known reserves.
In 2008, geologists calculated that the world’s known reserves of tantalum will last us for about 129 more years at today’s rate of consumption; if the demand increases, it might run out faster. If everyone in the world consumed it at US rate, than it would last for 18 years, only.
However, there are reasons that make it very hard to know for sure how long the minerals reserves will last:
As we discover new deposits of minerals, the amount of “known reserve” increases, as well as the years these minerals are available to us. That’s the main reason why some previously predicted shortages have not come to pass.
New technologies can modivy demand for minerals in unpredictable ways. Just as cell phones and computer chips boosted demand for tantalum, fiber-optic cables decreased demand for copper as they replaced copper wiring in communications applications;
Changing consumption patterns alter the speed with which we exploit mineral resources. Today China, India, and other nations are rapidly increasing their consumption, and as a result, global demand and market prices for many metals and other commodities are rising;
Advances in recycling technologies could help us to extend the lifetimes of some mineral resources.
Despite these sources of uncertainty, it is also good to keep in mind that the Earth’s supplie of mineral resources are finite, nonrenewable, and therefore, it is wise to search for ways to use them more sustainably. Although recycling might not be the final step, it certainly helps.
Again, some definitions…
Rocks are any solid aggregation of minerals.The type of rock in a given region affects soil characteristics and, therefore, influences the region’s plant community.
A mineral is any naturally occurring solid element or inorganic compound with a crystal structure, a specific chemical composition, and distict physical properties.
The difference between them is that rocks are made of minerals, but the opposit does not occur.
Rock cycle is a process in which rocks and minerals are heated, melted, cooled and broken down, and takes years to be complete, in a way that mineral resources become nonrenewable on human time scales, therefore, we should try to minimize and mitigate the many environmental and social impacts of our mining operations.
We mine metals from ores. A metal is an element that is lustrous, opaque, maleable, and can concuct heat and electricity. Some examples are iron, lead, gold, aluminum and tantalum. Many minerals we use do not contain metals, like sand and gravel, that provide construction and fill materials; phosphates, used as fertilizers; limestones and salts; and gemstones, such as diamond.
Substances used for fuel are also mined like uranium, used in nuclear power; and even though coal is not a mineral because it consists of organic matter, it is considered to be mined because of it’s relevance in general mining issues. Other organic fossil fuels are petroleum, natural gas, and alternative fossil fuels like oil sands and methane hydrates. You can watch an enterview about methane hydrates here.
There are many mining methods, such as strip mining; subsurface mining; open pit mining; placer mining and mountain top removal. They’re use depends on the nature of the mineral deposit. Each technique has advantages and disadvantages. We are going to talk about those on the next post.
Environment: Includes all living and nonliving things around us with which we interact. The use of the term environment, to mean a nonhuman or “natural” world apart from human interaction, is too narrow and incomplete; it hides the connection and dependance between human beings and nature.
Climate Change: Describes trends and variations in Earth’s climate, involving aspects such as temperature, weather patterns, and the effects felt by those changes.
Global Warming: The increase in the avarage temperature of the Earth’s surface. global warming and climate change are not identical, in fact, global warming is one of the consequences of climate change, even though warming does in turn, drive other forces of climate change.
Climate: Describes the atmospheric condition (temperature, moisture content, wind, precipitation, barometric pressure, solar radiation, etc.) of a large area through an extended period of time (years, centuries or millennia), while weather refers to the specific and local conditions over a period of hours or days.
Global warming seems to be generally perceived by the media and the majority of people as a serious problem, one that needs to be talked about often emphasizing the negative consequences in a desperate way to try mobilize societies to prevent so much destruction.
However, talking about the “Day After Tomorrow” and the possible self-destruction of the planet as we know it and proposing ideas too far ahead of our time as the only way to save our future generations doesn’t help at all. Instead of mobilizing and bringing people toward the cause, such speech works like a repellent. Environmental issues repells people; environmentalists are often thought as annoying fundamentalists, believed to be against the growth and development because their ideas would cause the economy to colapse.
The pessimistic tone regarding the predictions of our future along with the surreal ideas to prevent it from happening only causes people to panic. Panicked people are far less likely to act progressively, especially if the situation seems so direly hopeless. People don’t realize what they can do as individuals to slow down global warming and diminish it’s consequences. They only feel powerless, useless and in disbelief of every possible solution. So they do the one thing that panicked people do: Nothing good.
Yes, we must talk about the dangers our future generations may suffer for the way we live our lives. However, it is very delicate to talk about changes and the changes required to prevent all those predicted disasters. Everybody is afraid of changes because it leads to the unknown, and nothing is more scary than the unknown. Therefore, there’s a need to be extra cautious when we talk to people about the need of changing our life habbits, this can not be something imposed simply because it’s impossible to really obligate everybody do something. The key is more than convince people about changing their habbits, but to make them convince themselves. That’s the very best persuasion tactic because people act accordingly to what they believe in.
In my perception, global warming is a conflict. A global economical, political, social and ecological conflict because it affects directly peoples needs, interests and concerns. It doesn’t matter if everybody believes on it or not, everybody’s life is affected by global warming.
However, the word “conflict” generally carries a very negative connotation, for it is automatically related to words like “pain”, “struggle”, “friction”, “fight”, or seen as a “win and lose” situation and so on. Therefore, some people may
What people sometimes forget is the positive side of a conflict, because it can also mean opportunity; opportunity to clarify issues and feelings; to learn to deal with other people and different cultures; to solve problems constructivelly; to look for positive outcomes for humanity as a whole so that our differences can be put aside for a greater good and a common interest: a healthy, clean world that will be able to sustain our species for generations. Opportunity can be seen as a challenge to create a new begining, or at least a better end.
This is what this blog is all about… My goal here is not to judge whether or not technology or politics or companies are good or bad for the people, the environment, the economy or the government, nor is it so restate all the causes of global climate change, something that has become such common knowledge! What I want to present is constructive information to promote debates, inspire ideas, spark curiosity, for from this type of conflcit, solutions may rise.
If you are sick and tired of only seeing and hearing all the catastrophic consequences of global warming and not enough on how to help prevent it from becoming worse, then you have found the right spot, for it is here you will have the opportunity to become aware of possible solutions for the problems global warming has caused. Of course, we can not stop mentioning the effects of climate change, however, this won’t be our focus; our focus will be what we can do as individuals, as a country and as a global society to help solving this issue.
I hope you enjoy reading this as much as I’ve enjoyed writing it!!! Let me know if you have any questions, comments or critiques! I’ve always got an open ear, hope to hear your opinions soon!
