The condition of today’s environment has been affected by many factors, some of which are positive, which benefit the environment. In contrast, other environmental effects are negative, meaning they damage or cause harm to the environment. One factor, which affects the environment, is humans. The negative ways, which we affect the environment are, through the building, farming, pollution, and quarrying. However, there are some positive effects on the environment caused by humans, such as the conservation of endangered species, protection of the ozone layer, and the conservation of the earth’s resources. This essay, therefore, will be set out into two main parts. The first of these two parts will discuss how humans hurt the environment; this will focus on pollution. Secondly, I will discuss the positive effects we have on the environment; this section of the essay will discuss conservation and the protection of the ozone layer.
I will then conclude this essay by giving my personal view on how humans affect the environment and whether the overall effect is negative or positive. As mentioned above, there are many negative ways in which we as humans negatively affect the environment. One way in which we harm the environment is through our pollution. Polluting is a critical issue when discussing the environment and factors, which affect it. One form of pollution, which affects the environment, is air pollution. Air pollution involves the air being polluted by gases, dust and smoke from vehicles and industry. This type of pollution causes many problems such as various lung diseases, including cancer, bronchitis and emphysema, all of which can be lethal to both animals and humans alike. Some pollutants, which cause these diseases, are lead compounds, hydrocarbons and carbon monoxide, all released by vehicle engines.
Nitrogen oxides are also a cause of lung disease and cause acid rain, which leads to soil erosion and damages plant and tree roots, causing many to die. Acid rain has a similar effect on the fish, which can also die because of the rain. Other pollutants such as sulphur dioxide, one of the fatal gases, are released through the combustion of fuels and from factories. A major issue of air pollution is its affect on the ozone layer. CFCs or Chlorofluorohydrocarbons are released from aerosol spray cans and car engines, and nitrogen monoxide (NO) comes from the exhausts of some flight craft such as Concorde’s. Both of these gases react with ozone (O3) and are oxidized as a result. The chemical equations for the reaction of CFC and Ozone are as follows:
- Ozone + CFC –> Oxygen + Oxidation products
- The chemical equation for the reaction, which occurs between nitrogen monoxide and Ozone, is: Ozone + Nitrogen monoxide –> Oxygen + Nitrogen dioxide O3 (g) + NO (g) –> O2(g) + NO2(g)
These reactions have caused the Ozone layer to begin to become thinner. This is a bad thing because, in some areas, people will be left exposed to the harmful UV rays, from which the Ozone layer would usually protect us. This, in turn, puts people at risk of skin cancer and damages the plants and other living organisms. Another form of pollution is water pollution. Water pollution means that water is polluted by wastes from factories, oil and the runoff of surplus agrochemicals from the land. This type of pollution causes much damage to the environment; many businesses are located on riverbanks meaning that they discharge their waste into rivers. This has caused many of Britain’s largest rivers to become too dirty to keep fish alive. An example of this is in Mersey, where in the 1930s, fishers could make a living. However, now it is too foul to keep fish, meaning fishers can no longer earn a living in the area; the dumping of waste caused this by industries in the estuaries.
Thermal pollution is another type of water pollution. This is when power stations use the water from rivers for cooling and return the water to a higher temperature. When the temperature rises too much, the biological oxygen demand increases; in other words, the organisms in the water require more oxygen. This can cause many problems, such as the death of fish that cannot get the required amount of oxygen in time. A severe type of water pollution is pollution by agriculture. This involves the use of pesticides and fertilizers. When farmers use fertilizers, there is often excess fertilizer, which the plants do not absorb. This is washed into the lake, therefore providing the plants with an extra supply of nitrates and phosphates, meaning there is mass production of algae in the lake or an algae bloom. This means that the natural cycle of the lake is disrupted; the mass algae in the lake soon dies and is fed upon by bacteria.
The high bacterial activity means that much of the dissolved oxygen is consumed, causing many fish to die from lack of oxygen. This type of water pollution involving the accidental fertilization of lakes and rivers is known as eutrophication. In addition, there are certain harmful pesticides, which are also washed into the river. These are sometimes referred to as the ‘drins,’ dieldrin, endrin, and aldrin. These can cause many problems, such as liver cancer at high levels, and because fish do not excrete them, they can build up to 6000 times the level in the water. As I stated above, not all human effects on the environment are negative; many are positive. The main way, which we have a positive affect on the environment is through conservation. Conservation means saving or conserving something.
One thing we try to conserve for the benefit of the environment is the use of non-renewable energy resources. For example, we reduce the pollution usually caused by factories by using wind turbines, which cause no pollution at all. In addition, reducing the use of non-renewable energy sources, such as fossil fuels (coal, oil, and gas), reduces the number of dangerous gases polluting the air. Another example of conservation is the human conservation of species. This has been demonstrated through laws applied in certain countries to protect species such as elephants and their hunting. In addition, conservationist groups such as the Convention on international trade in endangered species (CITES) have asked governments to pass laws, which protect threatened species.
One of the most popular conservationist groups, the WWF (world wildlife fund, conserved a whole ecosystem of tigers in India in 1973. They made sure laws were passed to protect them, resulting in a dramatic increase in tigers. Their work has not stopped there; they have saved many animals such as the Arabian Oryx, Przewalski’s horse, Pere David’s deer and the European Bison through captive breeding programmes. In addition, the WWF proposed a plan called the world conservation strategy, which was aimed at political leaders and hoped to get them to focus on the economic and environmental problems. Other conservationist groups include Friends of the earth and Green peace, who try to persuade people to adopt environmentally friendly attitudes. Another strategy they use is to try to convince governments and political parties to adopt conservationist policies.
The problem with the ozone layer has become so serious that many leaders have felt the need to address the situation. This has been done in many countries. Two examples of this are the US and the UK. CFC’s the main cause of the ozone layer problem, have been banned in the USA. In the UK, the government has agreed to reduce the number of CFCs by 50%. In addition, CFC-free aerosols are being introduced in the UK, meaning they are ozone friendly. Over the past years, we as humans have had an overall negative effect on the environment. This has caused many of today’s environmental problems, such as the holes in the ozone layer and the greenhouse effect. However, we have also had many positive effects on the environment and have realized our past mistakes. This is shown through measures such as the reduction of CFCs in aerosols. Overall, our impact on the environment has been negative; however, I feel that in the future, we will continue to have a positive impact, and therefore create an overall positive effect on the environment.