Discuss the impact Man has had on the Enviroment.

Nitrates are also harmful to the environment. Calcium, sodium, potassium, and ammonium nitrates are used in fertilisers to provide a source of nitrogen for plant growth. If these nitrates get into the water flow then they can, like phosphates, have damaging effects on the life that live there.

Factory chimneys emit Sulphur Dioxide, which has to be monitored. Inside the chimneys are several filters that sift out the solids in the emissions. Sulphur dioxide emitted into the atmosphere by industrial processes is ultimately converted into dilute sulphuric acid, returning to Earth as acid rain. For this reason, sulphur dioxide is a major cause of air pollution. Acid rain is rain with a greatly lowered pH. Oxides of nitrogen are also emitted from car exhausts that also add to the formation of acid rain. The acid rain in turn comes down and erodes buildings and other things. In heavily industrialised areas of America, ladies have reported holes appearing in their tights when rain falls on them. In areas with plenty of limestone rocks, the effects are reduced because the acid reacts with the rocks and neutralises the rain. In areas without limestone, lakes become acidic, leading to the death of the wildlife. Trees are also killed as a direct result of acid rain. Many governments are ignoring the warnings and not controlling the emissions from their industry before it is too late.

Crude oil, known as petrol, is used in the manufacture of fertilisers, medicines, plastic, building materials, paints and to generate electricity. It is also used for the fuelling of transport such as cars and planes. Petrol contains hydrocarbons and sulphur. When the hydrocarbons and sulphur are burned for use they give off sulphur dioxide and carbon dioxide. These gases are harmful to the environment. Sulphur dioxide forms sulphuric acid and causes acid rain, carbon dioxide adds to the greenhouse effect. The greenhouse effect means that the levels of carbon dioxide and other greenhouse gases that usually prevent heat loss from the earth are increasing. This results in raised temperatures on earth leading to partial melting of the polar ice caps. If the ice caps melted too much some countries would be flooded, if they were all to melt then the whole world would be underwater.

Deforestation is another major impact man has on the environment, trees are chopped down to provide timber, or to free up land for other uses like arable cropping or for houses and roads. Deforestation though causes problems. It destroys the habitats of vast amounts of wildlife and lots of species are in danger of extinction due to the removal of trees. Also without trees to intercept rainfall and to hold soil together there is increased soil erosion. This soil erosion can remove nutrient rich soil leaving coarse sandy particles turning good soil to desert.

The greenhouse effect is also a possible major problem. Carbon dioxide from the combustion of fossil fuels increases the amount of carbon dioxide in the atmosphere and this new carbon dioxide increases the amount of heat that is re-radiated back down to earth. This means that slowly the earth is heating up, although some people feel that this is just due to the absence of a mini-ice age. However if the earth is undergoing a greenhouse like effect the polar ice caps could eventually come to melt and low lying areas of the earth could be flooded.

There is a need to produce more food for the population and a need to preserve the wildlife and the environment. It is essential to satisfy the needs of the expanding population but it is also essential to preserve the environment. Living organisms are dependent on each other, if a tiny little fungus or algae plants were destroyed then the rest of the food chain would be affected. The algae or fungi are the producers so the primary consumers have nothing to eat so they die and the secondary consumers then have nothing to eat so they die. Plants and can be used for many purposes which is why they are becoming extinct. Drugs have been derived from plants. Genetic variation also decreases with the loss of species and new genes can never be discovered e.g. for crop breeding. The reduction of trees is leading to more carbon dioxide in the air and therefore increasing global warming.

The government is trying to reverse some of the effects man has had on the environment by, for example, paying farmers to replace hedgerows in their fields which had previously been removed to make room for more crops. Factories have to monitor the amount of emissions that come from their chimneys very closely and if they emit too much sulphur dioxide or other harmful chemicals then the factory can be closed down. Factories also have to monitor the amount of chemicals that they pump into the drains, they have to neutralise the effluent before it is pumped into the main drainage system to prevent any chemicals getting into the main sewers and into the rivers and affecting the ecosystem of the rivers. Some waste can be recycled, at the water treatment works they can make the water clean enough, may be not to drink, but to water non-edible crops and for industrial processes and recreation.

Crop rotation is another way in which the land is being preserved a little more. Different crops are being grown in different places so that the same nutrients aren't being used from the same piece of soil every time and therefore the nutrients are being used in equal quantities. The nutrients in the soil then have time to replenish themselves over the years. In addition, natural fertilisers are being used like farmyard manure instead of phosphates and nitrates. This means that the nutrients are released slowly as they decay and therefore improve the structure of the soil.

Organic food production seems to be a very good idea. It protects the environment as it doesn't involve the use of herbicides and fertilisers and it allows the farmers to carry on producing food in large enough quantities. The government incentives are helping farmers to become established in the organic farming trades. With organic food becoming more popular with the consumer, the demand for organic produce is increasing. Organic food tends to be more expensive as the entire crop isn't perfect but it is environmentally friendly.

Man's effects on the environment are many but the effects are being slowed down and where possible reversed. The consequences of many years of abuse to the earth are being realised and people are trying to do something about it. Tillage operations that prepare the soil for planting and control weeds expose bare soil to possible erosion by wind and water. Global warming is being reduced as much as possible by the reduction of toxic emissions and wastewater is being recycled instead of pumped into rivers and seas. Man is trying to reverse and slow down the effects on the environment although some things cannot be reversed.