The whole point of crop farming (monoculture) is to remove a mixed population of trees, shrubs etc and replace it with a dense population of wheat or beans. So maximum crop numbers can be achieved every attempt is made to destroy threat to the crop such as pigeons and rabbits, which try to feed on the harvest. The balance between life and natural plant is upset; the animals are forced to live in small areas of woodland, hedgerow or heath. There is not enough food to go around and the stronger survive, many animals will die but some species may even die out.
When draining wetland areas it destroys the habitat of its inhabitants such as fish, swans and ducks. They will move to other areas but this causes that area to become overpopulated and not having enough food for all, causing them to die out.
Waste disposal is a fast increasing problem as the population is increasing so is the amount of waste products. Landfill sites take up space, which would have been used by many different species before it was used for waste disposal. The rubbish makes the land inhabitable for animals also dangerous as many animals get injured by glass, sharp shards of metal, along with others who get trapped in the plastic rings used to hold beer cans and die.
Pollution
Sewage contains bacteria from human intestine, which can be harmful to humans and animals. These harmful bacteria must be removed along with chemicals such as soap and detergent to make them safe enough to be released into the river. If sewage were released into rivers before being treated it would no doubt kill any inhabitants in the river. Some bacteria cause diseases such as typhoid and cholera when they get inside human intestine. The faeces passed by those suffering of the disease will contain the harmful bacteria. If these bacteria was released into rivers and got into drinking water the diseases could be spread to hundreds of people
Many industrial processes produce poisonous waste products. E.G Electroplating produces waste containing copper and cyanide, if release into rivers it would poison animals, plants and even humans who drink the water.
Eutrophication is when nitrates and phosphates used on farmland and sewage escape into rivers they causer excessive growth of microscopic green plants. As the rate of increasing is so rapid the microscopic animals that feed on them can’t keep them in check. This causes them to die and sink to the bottom of the river or lake. This is where there bodies are broken down by bacteria which needs oxygen to break them down which is taken from the water. The water becomes deoxygenated and can no longer support the animal life, the fish and other organisms die of suffocation.
It is simplified in the diagram below
Here is an example of the water surface in eutrophication.
Coal and oil contain sulfur, when these fuels are burned sulfur dioxide is given off into the air. Although tall chimneys of factories send sulfur dioxide into the air some of it still dissolves in rain water and forms an acid, this is what’s known as acid rain it can reduce tree/plant growth and damage leaves, it also slowly dissolves limestone and mortar on buildings. This form of pollution has been going on for many years and getting worse, in some places it is destroying forests and contributing to the death of fish.
The earth’s surface receives and absorbs radiant heat from the sun. As shown in the diagram below, it re-radiates some of its heat back into space while the remainder is absorbed and warms the earth. The energy radiated back from the earth in the form of long wavelength is absorbed by the earth’s atmosphere. The atmosphere acts like the glass in a greenhouse, it lets in heat and light from the sun but reduces but reduces the amount of heat that escapes. Not all of the atmospheric/greenhouse gases are equally effective at absorbing the infrared radiation oxygen and nitrogen.
The gases, which do absorb the IR radiation, are water vapour, carbon dioxide, methane and pollutants such as CFC’s. These gases are at low concentrations but if these were to continue increasing the climate would get warmer. The largest build up of methane gas is over rubbish tips and cattle/rice fields. most tips have got pipes which collect the methane gas caused by the breakdown of organic matter such as vegetables and paper, this gas can be used as fuel. Methane gas however contributes to the greenhouse effect and as cattle/rice fields have no method of collecting the natural production of the gas it is left and contributes to global warming.
Global mean surface temperatures have increased 0.5-1.0°F since the late 19th century. The 20th century's 10 warmest years all occurred in the last 15 years of the century. Of these, 1998 was the warmest year on record. The snow cover in the Northern Hemisphere and floating ice in the Arctic Ocean has decreased. Globally, sea level has risen 4-8 inches over the past century. Worldwide precipitation over land has increased by about one percent and especially in the United States frequency of extreme rainfall events has increased
Nitrogen oxides
Nitrogen oxides along with sulfur dioxide and carbon monoxide are produced and released into the atmosphere by cars and a lot of factories all over the world, a large quantity of this usually in busy areas such as city’s causes the unnatural build up of smog
Although smoke produced by cars etc has been largely eliminated from our towns/ city’s vehicle exhaust gases, contain microscopic particles coated in hydrocarbons. It is estimated that these hydrocarbons are the cause of around 10,000 deaths every year, particularly with people suffering lung diseases such as bronchitis.
Pesticides
Many farmers use chemicals to encourage healthy crop growth, prevent weed growth and prevent damage by pests and disease. This can effect the crops by increasing their commercial value but it also can mean that the crop are less healthy to consumers because traces of the plant may contain chemicals left in the plant.
Pesticides are chemicals that destroy pest’s weeds and diseases, when these are used the yield (amount produced) of a crop can be dramatically increased.
Herbicides are chemicals, which can be specific to destroying a species of plant or part of a plant or just to kill all plants.
When an excess of pesticide/ herbicide is produced then it can badly disrupt food chains and bioaccumulation occurs. This is when insecticides are not broken down and become concentrated from one level in the food chain (Trophic level) to another in fatty deposits of top carnivores such as birds of prey.
E.g. in the late 1950’s sparrow hawk and peregrine populations fell dramatically due to the introduction of insecticides, this is because particular insecticides caused shell thinning and circumstantially break during laying.
Insecticides also took effect on animals living in soils and on the plants etc.
Conclusion
Personally I fell these are all problems that should be improved on, but I fell most strongly about global warming. Although precautions have been taken to prevent this problem worsening, something need to be done as temperature increases and sea level increase are currently at a quite alarming rate and are proven to get worse and worse.
