Summary
Pollution involves the introduction of harmful substances into the environment, often due to human activities, making it unfit for life. Pollutants — substances that cause pollution. Example: Mercury and lead from industrial waste.
- Eutrophication — a process where excess nutrients lead to overgrowth of algae in water bodies. Example: Algal blooms from excess fertilizers.
- Non-biodegradable plastics — plastics that do not break down easily and harm ecosystems. Example: Marine animals ingesting plastic.
- Greenhouse gases — gases that trap heat in the Earth's atmosphere, contributing to climate change. Example: Carbon dioxide and methane.
Exam Tips
Key Definitions to Remember
- Pollution
- Eutrophication
- Greenhouse gases
Common Confusions
- Mixing up causes and effects of pollution
- Confusing greenhouse effect with global warming
Typical Exam Questions
- What is eutrophication? Eutrophication is the process where excess nutrients in water bodies lead to excessive algae growth and oxygen depletion.
- How do non-biodegradable plastics affect marine life? Marine animals may ingest plastics or become entangled, leading to injury or death.
- What is the enhanced greenhouse effect? It is the increase in Earth's average temperature due to higher levels of greenhouse gases.
What Examiners Usually Test
- Understanding of the causes and effects of pollution
- Ability to explain processes like eutrophication
- Knowledge of the impact of greenhouse gases on climate change