11.7.2 Strategies to Solve Acid Rain

1. Acid rain mitigation

• Measures to reduce emissions of sulphur dioxide and nitrogen oxides from industrial units, power plants, and vehicles are important for reducing acid rain.
• This can be achieved through:
• Introduction of anti-pollution technologies
• Use of cleaner fuels

(b) Flue gas desulfurization: - Flue gas desulfurization systems, such as wet or dry scrubbers in power plants and industrial units, can remove sulphur dioxide from flue gases before they are released into the atmosphere.

(c) Low sulphur fuels: - Promoting low sulphur fuels can also minimize the amount of sulphuric acid in the atmosphere that causes acid rain.

Simple explanation: Reduce SO₂ and NOₓ emissions by using cleaner fuels and pollution-control technology.

2. Catalytic converters in vehicles

• The promotion of catalytic converters in vehicle exhaust systems can reduce emissions of harmful gases and volatile organic compounds.
• Converters contain catalysts such as platinum, palladium, and rhodium, which transform harmful gases into less harmful substances.

Simple explanation: Catalytic converters help reduce the pollutants that cause acid rain.

Intermediate Level

Why These Strategies Work

• Renewable energy → no CO₂ emissions.
• Energy efficiency → less fuel burned → less CO₂.
• Afforestation → trees absorb CO₂.
• Sustainable agriculture → less N₂O and CH₄.
• Hydrogen economy → clean fuel, no CO₂.
• Circular economy → less waste → less CH₄ from landfills.

• Emission control → less SO₂ and NOₓ in the atmosphere.
• Flue gas desulfurization → removes SO₂ before it leaves the chimney.
• Low sulphur fuels → less SO₂ produced when burned.
• Catalytic converters → convert NOₓ to N₂.

Simple explanation: These strategies either reduce the production of pollutants or remove them before they enter the atmosphere.

The Paris Agreement

The Paris Agreement is an international treaty on climate change.

• Limit global warming to well below 2 °C above pre-industrial levels.
• Pursue efforts to limit warming to 1.5 °C.

• Countries submit nationally determined contributions (NDCs).
• Countries report on their emissions and progress.
• The agreement is legally binding in some aspects.

Simple explanation: The Paris Agreement is a global promise to fight climate change.

The Circular Economy

• Minimizing waste
• Promoting recycling
• Keeping materials in use for as long as possible

• Reduces greenhouse gas emissions.
• Conserves resources.
• Reduces pollution.

Simple explanation: Instead of "make, use, throw away," a circular economy is "make, use, recycle, reuse."

Flue Gas Desulfurization

Flue gas desulfurization (FGD) is a technology used to remove SO₂ from exhaust gases.

• Wet scrubbers — use a liquid to absorb SO₂.
• Dry scrubbers — use a dry reagent to absorb SO₂.

• Flue gas passes through a scrubber.
• SO₂ reacts with the scrubbing material (e.g., lime or limestone).
• The product is removed as a solid waste or used as a by-product.

Simple explanation: Scrubbers "wash" the SO₂ out of the exhaust gas before it goes up the chimney.

Important Points

• - Climate change strategies:
• 1. Transition to renewable energy (wind, solar, hydro, geothermal).
• 2. Energy efficiency.
• 3. Reduce CO₂ from transport (electric vehicles, public transport, walking, cycling).
• 4. Afforestation and reforestation (planting trees, forest regeneration).
• 5. Sustainable land use (organic fertilizers, sustainable agriculture).
• 6. Move to a low-carbon economy (hydrogen economy, circular economy).
• 7. International cooperation (Paris Agreement, policy support).
• - Acid rain strategies:
• 1. Emission control (reduce SO₂ and NOₓ).
• 2. Flue gas desulfurization (wet or dry scrubbers).
• 3. Low sulphur fuels.
• 4. Catalytic converters in vehicles.
• - Paris Agreement: limit global warming to well below 2 °C, aim for 1.5 °C.
• - Circular economy: minimize waste, promote recycling.
• - Strategies are interrelated — require a holistic approach.

Remember

• - Climate change: renewable energy, energy efficiency, green transport, afforestation, sustainable agriculture, hydrogen economy, circular economy, Paris Agreement.
• - Acid rain: emission control, flue gas desulfurization, low sulphur fuels, catalytic converters.
• - Paris Agreement: 2 °C target, 1.5 °C aim.
• - Circular economy: reduce, reuse, recycle.
• - Flue gas desulfurization: remove SO₂ from exhaust gases.
• - Strategies are interrelated.

Common Mistakes

• 1. Thinking only one strategy is enough. Solving environmental problems requires a combination of strategies.
• 2. Confusing the strategies for climate change and acid rain. Some overlap (e.g., reducing fossil fuel use helps both), but they have different specific strategies.
• 3. Thinking the Paris Agreement is legally binding for all countries. It has legally binding and non-binding aspects.
• 4. Forgetting the role of individuals. Individuals can contribute by using public transport, saving energy, and recycling.
• 5. Thinking flue gas desulfurization removes all pollutants. It specifically removes SO₂.
• 6. Confusing the circular economy with recycling. The circular economy is broader — it includes reducing, reusing, and recycling.

Quick Revision

• Transition to renewable energy (wind, solar, hydro, geothermal).
• Energy efficiency.
• Reduce CO₂ emissions from transport (electric vehicles, public transport, walking, cycling).
• Afforestation and reforestation.
• Sustainable land use (organic fertilizers, sustainable agriculture).
• Move to a low-carbon economy (hydrogen economy, circular economy).
• International cooperation and policy (Paris Agreement, policy support).
• Emission control (reduce SO₂ and NOₓ).
• Flue gas desulfurization (wet or dry scrubbers).
• Low sulphur fuels.
• Catalytic converters in vehicles.

60-Second Revision

• Climate change: renewable energy, efficiency, trees, green transport, Paris Agreement.
• Acid rain: emission control, scrubbers, low sulphur fuels, catalytic converters.
• Paris Agreement: 2 °C target, 1.5 °C aim.
• Circular economy: reduce, reuse, recycle.
• Warning: solving environmental problems requires a combination of strategies, not just one.