This is a list of environmental issues that are due to human activity. These articles relate to the anthropogenic effects on the natural.
- Intensive farming
- Land degradation
- Overpopulation
Intensive farming
Intensive farming or intensive agriculture is an agricultural production system characterized by the high inputs of capitall , fertilizerss , labourr , or labour-saving technologies such as pesticides relative to land area. This is in contrast to the concept of Extensive Agriculture which involves a low input of materials and labour with the crop yield depending largely on the naturally available soil fertility, water supply or other land qualities.Modern day forms of intensive crop based agriculture involve the use of mechanical ploughing, chemical fertilizers, herbicides, fungicides, insecticides, plant growth regulators and/or pesticides. It is associated with the increasing use of agricultural mechanization, which have enabled a substantial increase in production.
Intensive animal farming practices can involve very large numbers of animals raised on limited land which require large amounts of food, water and medical inputs (required to keep the animals healthy in cramped conditions).Very large or confined indoor intensive livestock operations (particularly descriptive of common US farming practices) are often referred to as Factory farming and are criticised by opponents for the low level of animal welfare standards and associated pollution and health issues.
Advantages
- Intensive agriculture has a number of benefits.
- Significantly increased yield per available space than extensive farming.
- Often leads to cheaper priced products because of better general production rate for the cost of raw materials.
- Not much space for the animal(s) to move therefore less energy used up; so less food supplied to the cattle, which leads to cheaper products.
- Many people feel its necessary to use intensive farming for better profits and economy.
Disadvantages
- Intensive farming alters the environment in many ways.
- Limits the natural habitat of some wild creatures and can lead to soil erosion.
- Use of fertilizers can alter the biology of rivers and lakes.Some environmentalists attribute the hypoxic zone in the Gulf of Mexico as being encouraged by nitrogen fertilization of the algae bloom.
- Pesticides can kill useful insects as well as those that destroy crops.
- Generally not sustainable.
- Often results in an inferior product.
- Use of chemicals on fields creates run-off, excess runs off into rivers and lakes causing pollution.
- Animal welfare is significantly decreased compared to organic, animals are kept in tight living conditions, over-fed and only have a small life span before being slaughtered
http://en.wikipedia.org/wiki/Intensive_farming
Land degradation
Land degradation is a concept in which the value of the biophysical environment is affected by one or more combination of human-induced processes acting upon the land .Natural hazards are excluded as a cause; however human activities can indirectly affect phenomena such as floods and bushfires.
It is estimated that up to 40% of the world's agricultural land is seriously degraded.
Causes
Overgrazing by livestock can lead to land degradation
Land degradation is a global problem, mainly related to agricultural. The major causes include:
- Land clearance, such as clearcutting and deforestation
- Agricultural depletion of soil nutrients through poor farming practices
- Livestock including overgrazing
- Urban conversion
- Irrigation and overdrafting
- Land pollution including industrial waste
- Vehicle Off-roading
- Weeds
Effects
Soil erosion in a wheat field near Pullman, USA.
The main outcome of land degradation is a substantial reduction in the productivity of the land. The major stresses on vulnerable land include:
- Accelerated soil erosion by wind and water
- Soil acidification or alkalinisation
- Salination
- Destruction of soil structure including loss of organic matter
- Derelict soil
Severe land degradation affects a significant portion of the earth's arable lands, decreasing the wealth and economic development of nations. Land degradation cancels out gains advanced by improved crop yields and reduced population growth. As the land resource base becomes less productive, food security is compromised and competition for dwindling resources increases, the seeds of famine and potential conflict are sown.
Unless land rehabilitation measures are effective a downward eco-social spiral is created when marginal lands are nutrient depleted by unsustainable land management practices resulting in lost soil resilience leading to soil degradation and permanent damage.
We often assume that land degradation only affects soil fertility. However, the effects of land degradation often more significantly affect receiving water courses (rivers, wetlands and lakes) since soil, along with nutrients and contaminants associated with soil, are delivered in large quantities to environments that respond detrimentally to their input.
Land degradation therefore has potentially disastrous effects on lakes and reservoirs that are designed to alleviate flooding, provide irrigation, and generate hydroelectricity.
http://en.wikipedia.org/wiki/Land_degradation
Overpopulation
Overpopulation refers to a condition where an organism's numbers exceed the carrying capacity of its habitat. In common parlance, the term usually refers to the relationship between the human population and its environment, the earth.
Overpopulation is not a function of the size or density of the population. Overpopulation is determined using the ratio of population to available sustainable resources. If a given environment has a population of ten, but there is food or drinking water enough for only nine, then that environment is overpopulated; if the population is 100 individuals but there is enough food, shelter, and water for 200 for the indefinite future, then it is not. Overpopulation can result from an increase in births, a decline in mortality rates due to medical advances, from an increase in immigration, a decrease in emigration, or from an unsustainable biome and depletion of resources. It is possible for very sparsely-populated areas to be overpopulated, as the area under consideration may have a very meager or non-existent capability to sustain human life (e.g. the middle of the Sahara desert or Antarctica).
The resources to be considered when evaluating whether an ecological niche is overpopulated include clean water, clean air, food, shelter, warmth, and other resources necessary to sustain life. If the quality of human life is addressed as well, there are then additional resources to be considered, such as medical care, employment, money, education, fuel, electricity, proper sewage treatment, waste.
Some countries have managed to substantially increase their carrying capacity by using technologies such as modern agriculture, desalination, and nuclear power. Some economists, such as Thomas Sowell and Walter E. Williams have argued that poverty and famine are caused by bad government and bad economic policies, and not by overpopulation. In his book The Ultimate Resource, economist Julian Simon argued that higher population density leads to more specialization and technological innovation, and that this leads to a higher standard of living. Simon also claimed that if you look at a list of countries ranked in order by population density, there is no correlation between population density, and poverty and famine, and instead, if you look at a list of countries ranked in order by government corruption, there is a huge correlation between government corruption, and poverty and famine.
http://en.wikipedia.org/wiki/Overpopulation
My point of view:
From my research about environmental issues, I've found that most of the activities comes from human activity.There good and bad effects from all the activities.. Lets talk about intensive farming first..This activity relate to an agricultural..There are many ways to accomplish this activity such as they were using oysters, terrace, and rice paddy..Usually the workers is someone that staying in villages..They work together to get better results of the crops..Aquaculture is the cultivation of the natural produce of water (fish, shellfish, algae, seaweed and other aquatic organisms). Intensive Aquaculture can often involve tanks or other highly controlled systems which are designed to boost production for the available volume or area of water resource.
For land degradation, the loss of arable land has been caused by a number of factors, many or most of which are tied to human development. The primary causes are deforestation, overexploitation for fuelwood, overgrazing, agricultural activities and industrialization. On the global basis, the soil degradation is caused primarily by overgrazing (35%), agricultural activities (28%), deforestation (30%), overexplotation of land to produce fuelwood (7%), and industrialization (4%).
The patterns are different in the various regions. In North America, agriculture has been responsible for 66% of the soil loss, while in Africa, overgrazing is responsible for about half of the soil degradation.
The economic reasons for these processes are complex and are linked to the particular characteristics of each region. Some of these issues will be discussed later in the course, as part of case studies.
Last but not least,we will talk a little bit of overpopulation.Thinkers such as David Pimentel,a professor from Cornell University, Virginia Abernethy, Alan Thornhill,Russell Hopffenberg and author Daniel Quinn propose that like any animals, human populations predictably grow and shrink according to their available food supply – populations grow in an abundance of food, and shrink in times of scarcity.
Proponents of this theory argue that every time food production is increased, the population grows. Some human populations throughout history support this theory. Populations of hunter-gatherers fluctuate in accordance with the amount of available food. Population increased after the Neolithic Revolution and an increased food supply. This was followed by subsequent population growth after subsequent agricultural revolutions.
Critics of this idea point out that birth rates are lowest in the developed nations, which also have the highest access to food. In fact, some developed countries have both a diminishing population and an abundant food supply. The United Nations projects that the population of 51 countries or areas, including Germany, Italy, Japan and most of the states of the former Soviet Union, is expected to be lower in 2050 than in 2005. This shows that human populations do not always grow to match the available food supply; also, many of these countries are major exporters of food. Nevertheless, on the global scale the world population is increasing.
Reference:
http://en.wikipedia.org/wiki/Intensive_farming
http://en.wikipedia.org/wiki/Land_degradation
http://en.wikipedia.org/wiki/Overpopulation
