Reducing the Effects of Environmental Issues
Section: 10. Chemistry of the Environment | Syllabus: Cambridge IGCSE Chemistry (0620)
Strategies to Reduce Climate Change
- Planting trees (they absorb CO₂ during photosynthesis)
- Reduction in livestock farming (livestock digestion is a major source of methane)
- Decreasing use of fossil fuels
- Increasing use of hydrogen and renewable energy, e.g. wind and solar power
Worked Example
- Question (based on a real exam question): which row shows one way to increase and one way to decrease the amount of carbon dioxide in the air - options included "wind generation of electricity" / "using solar power", and "using diesel vehicles" / "planting trees"?
- Answer: using diesel vehicles (increases CO₂ - burning diesel is combustion of a fossil fuel) / planting trees (decreases CO₂ - absorbed during photosynthesis). The wind/solar row is wrong because both of those methods decrease CO₂ - neither increases it.
Strategies to Reduce Acid Rain
- Using catalytic converters in vehicles (reduce oxides of nitrogen)
- Reducing emissions of sulfur dioxide, by:
- using low-sulfur fuels
- flue gas desulfurisation, using calcium oxide to react with and remove SO₂ from waste gases before they are released: CaO + SO₂ → CaSO₃
Common Mistakes
- ❌ Picking a strategy such as "wind power" or "solar power" as something that increases CO₂
- ✓ renewable energy sources like wind and solar don't involve combustion, so they only ever decrease (or have no effect on) CO₂ emissions - they can never be the "increases" side of a comparison
Interactive revision notes, videos and practice questions load below.