Lesson Notes By Weeks and Term v5 - Grade 9

Lesson Video

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Performance objectives

• Identify three major human impacts on the environment.
• Describe specific South African environmental challenges.
• Explain and estimate a 'carbon footprint'.
• Discuss sustainable practices to reduce our impact.
• Understand the link between human impact and biodiversity loss.

Lesson summary

The environment is everything around us: the air, water, land, plants, animals, and even the built structures. As humans, we rely on the environment for everything from the air we breathe and the water we drink, to the food we eat and the materials we use to build our homes.

However, our activities are having a significant and often negative impact on the environment, threatening its ability to sustain us and future generations. In South Africa, this is particularly important as many communities rely directly on natural resources for their livelihoods. Issues like water scarcity, pollution from mining, and the impacts of climate change directly affect people's lives and well-being.

Lesson notes

2. 1.

Pollution: Pollution is the contamination of the environment by harmful substances called pollutants. These pollutants can affect air, water, and land.

Air Pollution: Caused by the release of harmful gases and particles into the atmosphere. Sources include burning fossil fuels (coal, oil, petrol) in power stations, vehicles, and industries. In South Africa, coal-fired power stations are a significant source of air pollution, especially in areas like Mpumalanga. Air pollution contributes to respiratory problems like asthma, and also contributes to acid rain and climate change.

Example:* Burning coal for electricity releases sulfur dioxide (SO2), a major air pollutant. Factories also release pollutants.

Example relating to learners:* Using aerosol cans and burning rubbish both contribute to air pollution.

Water Pollution: Occurs when harmful substances contaminate water bodies like rivers, lakes, and oceans. Sources include industrial waste, sewage, agricultural runoff (fertilizers and pesticides), and mining activities. In South Africa, acid mine drainage (AMD) from abandoned mines is a major source of water pollution, especially in Gauteng and Mpumalanga. AMD can make water acidic and toxic to aquatic life and human health.

Example:* Untreated sewage released into rivers pollutes the water and can spread diseases like cholera and typhoid.

Example relating to learners:* Throwing litter into streams and rivers pollutes the water and harms wildlife.

Land Pollution: Occurs when waste materials contaminate the soil. Sources include landfills, industrial waste, agricultural chemicals, and improper disposal of hazardous waste. Land pollution can contaminate groundwater, affect plant growth, and pose risks to human health.

Example:* Improper disposal of e-waste (electronic waste like old computers and cell phones) can leach toxic metals into the soil.

Example relating to learners:* Littering on the playground pollutes the land and makes it unsafe. 2.

2. Deforestation: Deforestation is the clearing of forests for other uses, such as agriculture, urbanization, and logging. Forests play a vital role in absorbing carbon dioxide from the atmosphere, regulating water cycles, and providing habitats for countless species. Deforestation contributes to climate change, soil erosion, loss of biodiversity, and flooding.

Example:* Clearing land for cattle farms or crops can lead to deforestation.

Impact on South Africa:* Deforestation impacts indigenous forests and woodlands, affecting biodiversity and water resources. 2.

3. Resource Depletion: Resource depletion refers to the unsustainable use of natural resources such as water, minerals, and fossil fuels. As the human population grows and consumption patterns increase, the demand for these resources rises, leading to their depletion.

Example:* Overfishing can deplete fish stocks in the ocean, leading to the collapse of fisheries.

Water Scarcity in South Africa:* South Africa is a water-stressed country, and over-extraction of water for agriculture, industry, and domestic use is exacerbating water scarcity. 2.

4. Climate Change: Climate change refers to long-term shifts in temperature and weather patterns, largely caused by human activities, particularly the burning of fossil fuels. The burning of fossil fuels releases greenhouse gases (such as carbon dioxide) into the atmosphere, trapping heat and causing the Earth's temperature to rise. This can lead to a range of impacts, including rising sea levels, more frequent and intense heatwaves, droughts, floods, and changes in rainfall patterns.

Example:* Burning coal in power stations releases large amounts of carbon dioxide into the atmosphere.

Impact on South Africa:* South Africa is particularly vulnerable to climate change, with projected increases in temperature and decreases in rainfall in many areas. This will impact agriculture, water resources, and human health. 2.

5. Biodiversity Loss: Biodiversity refers to the variety of life on Earth, including plants, animals, fungi, and microorganisms. Human activities, such as habitat destruction, pollution, and climate change, are driving biodiversity loss at an alarming rate. Biodiversity is essential for maintaining healthy ecosystems, providing ecosystem services (such as pollination and water purification), and supporting human livelihoods.

Example:* Clearing forests for agriculture destroys habitats and can lead to the extinction of plant and animal species.

Impact on South Africa:* South Africa is a biodiversity hotspot, with a high concentration of unique species. Human activities are threatening many of these species with extinction. Poaching of endangered species like rhino is a significant problem. 2.

6. The Concept of Carbon Footprint: A carbon footprint is the total amount of greenhouse gases (primarily carbon dioxide) generated by our actions. It's a measure of our impact on climate change.