Lesson Notes By Weeks and Term v5 - Grade 9

Lesson Video

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Performance objectives

• Explain at least three ways humans negatively impact the environment.
• Describe the causes and effects of pollution in South Africa.
• Explain the concept of resource depletion, focusing on water and forests.
• Identify strategies to reduce our negative impact and live more sustainably.

Lesson summary

The environment is everything around us – the air, water, land, plants, and animals. As humans, we rely on these natural resources for survival: we need clean air to breathe, fresh water to drink, fertile soil to grow food, and materials to build our homes.

However, our activities often have a significant negative impact on the environment. Understanding this impact is crucial for Grade 9 learners in South Africa because the consequences of environmental degradation are already visible in our communities. Issues like water scarcity, pollution in townships, deforestation leading to soil erosion, and the loss of biodiversity are realities we face.

Lesson notes

2.1 Pollution: Pollution is the contamination of the environment with harmful substances, known as pollutants. These pollutants can be gases, liquids, or solids.

Air Pollution: This is the contamination of the air by pollutants such as smoke, dust, gases (e.g., carbon monoxide, sulfur dioxide, nitrogen oxides), and particulate matter.

Causes: Burning fossil fuels (coal, oil, and gas) in power plants, vehicles, and industries. Burning wood and coal for heating and cooking (common in informal settlements). Industrial processes release harmful gases. Mining activities release dust and heavy metals into the air.

Effects: Respiratory problems (asthma, bronchitis), acid rain (damages buildings and ecosystems), global warming (climate change), smog (reduces visibility and harms health). South African

Examples: High levels of air pollution in industrial areas like Sasolburg and Secunda, as well as in townships where coal burning is prevalent, leading to high rates of respiratory illnesses. The burning of tyres during protests contributes significantly to air pollution.

Water Pollution: This is the contamination of water bodies (rivers, lakes, oceans, groundwater) by pollutants such as sewage, industrial waste, fertilizers, pesticides, and oil spills.

Causes: Improper disposal of sewage, industrial effluent discharge into rivers and dams, agricultural runoff containing fertilizers and pesticides, oil spills from ships and pipelines, mining activities contaminating water sources with heavy metals and acid mine drainage.

Effects: Waterborne diseases (cholera, typhoid), harm to aquatic life (fish kills, algal blooms), contamination of drinking water sources, eutrophication (excessive nutrient enrichment leading to oxygen depletion). South African

Examples: The Vaal River is heavily polluted by sewage and industrial waste. Acid mine drainage from abandoned mines pollutes water sources in Gauteng and Mpumalanga. Agricultural runoff pollutes rivers in farming areas.

Land Pollution: This is the contamination of the land surface by pollutants such as solid waste (garbage), chemicals, pesticides, and industrial waste.

Causes: Improper disposal of solid waste (littering, illegal dumping), landfills leaking harmful chemicals, industrial activities contaminating soil with heavy metals, agricultural use of pesticides and herbicides, mining activities leaving behind contaminated land.

Effects: Soil contamination (affects plant growth and can contaminate food crops), groundwater contamination, visual pollution (litter), harm to wildlife. South African

Examples: Overfilled landfills in urban areas, illegal dumping in open spaces, contamination of agricultural land with pesticides and herbicides, derelict mining sites posing environmental hazards. 2.2 Resource Depletion: Resource depletion refers to the consumption of a resource faster than it can be replenished. This primarily focuses on non-renewable resources, but renewable resources can also be depleted if they are used unsustainably.

Water Depletion: South Africa is a water-stressed country. Our water resources are under increasing pressure due to population growth, urbanization, industrialization, and climate change.

Causes: Over-extraction of water from rivers and aquifers, inefficient irrigation practices, water leaks in municipal water systems, pollution reducing the availability of usable water, drought conditions exacerbated by climate change.

Effects: Water shortages, restrictions on water use, competition for water resources, impacts on agriculture and industry, ecological damage to rivers and wetlands. South African

Examples: The severe droughts experienced in the Western Cape in recent years, water restrictions in major cities, conflicts over water rights between different users (agriculture, industry, communities).

Deforestation: This is the clearing of forests for other land uses, such as agriculture, urbanization, and mining.

Causes: Clearing forests for agriculture (especially for commercial farming), harvesting timber for fuel and construction, mining activities destroying forests, urbanization expanding into forested areas.

Effects: Soil erosion (loss of topsoil), loss of biodiversity (habitat destruction), climate change (trees absorb carbon dioxide), flooding (forests help regulate water flow), reduced water quality. South African

Examples: Deforestation in KwaZulu-Natal and Limpopo due to agriculture and timber harvesting. The loss of indigenous forests contributes to soil erosion and biodiversity loss. 2.3 Climate Change: Climate change refers to long-term shifts in temperatures and weather patterns. These shifts may be natural, but since the 1800s, human activities have been the main driver of climate change, primarily due to burning fossil fuels (like coal, oil, and gas), which produces heat-trapping gases.