Unit Focus 5.1 Human activities and how they affect the environment 5.2 Symptoms of an ailing Earth 5.3 Causal explanation to environmental destruction

Environment Crisis: This means the danger of gradual destruction of Earth. Causes: The constant changing human activities. TB: 58-59

5.1 Human activities and how they affect the environment

Negative Effects: 1.Mining of land rich in minerals creates mines later become derelict land when mining operations cease. Soil erosion occurs when the rain erodes the soil heaps and washes them down into rivers causing water pollution.

2.Construction of settlements can lead to irresponsible sewage dumping. 3.Industries that burn coal and other fossil fuels release carbon dioxide and poisonous gases into the atmosphere, causing air pollution. 4.Industries may discharge waste into the sea. Negative Effects:

5.Transport of imported oil can result in oil slicks due to leakage or accidents. 6.Increase in vehicular traffic also means increase in exhaust fumes released into the atmosphere, causing air pollution. Negative Effects:

Ecological catastrophe Human activities cause air and water pollution and the pollutants are added to the environment. This causes the imbalance of the eco- system or the destruction of one eco- system. Eg. Industrial waste endangers aquatic creatures.

The tragedy of Sahel 1. A drought is a period of dry conditions caused by the lack of rainfall. 2. The lack of rainfall during the drought will result in crop failures, thus resulting in a lack of food or famine. 3. The rainfall in the Sahel (between 1969 and 1990) was below the long-term average. The drought was associated with an increasingly arid regional climate.

The Bhopal accident 1.Pesticides are chemical substances that are used to kill pests which harm or destroy crops. 2.There is a need to increase food production. Killing pests will increase crop yields.

3.Methyl isocyanite, a toxic gas, is used in the manufacture of pesticides. A gas leak can cause an explosion, killing and blinding people and causing ill-health and disability. The over-use of such pesticides can cause ill-health in the long term.

Chernobyl’s nuclear blast 1.A nuclear power plant is used to generate electricity from nuclear power. 2.A small amount of uranium can generate a huge amount of electricity. The nucleus of an atom of uranium is split in two to release energy. The process is called nuclear fission.

3.Nuclear reactors produce radioactive wastes which could lead to serious health risks and death caused by cancer. 4.Nuclear power provides the energy needed but there are a lot of risks. Lives can be lost.

Effects of Environmental Crisis: A.Damage to human health polluted air with poisonous gases such as carbon monoxide, sulphur dioxide and nitrogen can cause irritation of the eyes, throat and skin. These gases may damage lung and subsequently affect breathing.

B.Damage to materials Chemical pollutants from factories can damage buildings. They discolour and corrode fine marbles and other finer materials and the buildings. Thus, the government must spend more money to restore the buildings. Effects of Environmental Crisis:

C.High economic cost As more people get sick because of the pollution, the government has to spend more money for building hospitals, clinics and other health care needs. The government also has to spend more money restoring public buildings damaged by pollution. Effects of Environmental Crisis:

5.3 Causal explanations to environmental destruction Read TB:

Causes of Environmental Crisis: 1.Population increase the increase in food production, industrial development, clearance of forests for more houses, roads and communication facilities and mining.

2.Technological changes more production of goods in factories need more raw materials and more fossil fuels to supply power. The increase mining activities cause environmental damage. The construction of modern HEP on rivers will destroy the natural environment of surrounding landscape. Waste disposal into rivers causes water pollution as well as the soil.

3.Human consumption pattern large amounts of fuels are burnt by road vehicles. The increased number of vehicles release harmful gases such as carbon dioxide, sulphur dioxide and nitrogen oxide into the air.

Read TB: 64 Other causes: greed and consumption habits of individuals. Population may increase, but if each individual lives within a certain levels of comfort or a sustainable level of development, then there should be sufficient resources from our Earth.