BEVAE-181 Solved Assignment 2024-2025 | How does air pollution affect the atmospheric processes?

BEVAE-181 Solved Assignment 2024-2025 | ENVIRONMENTAL STUDIES | IGNOU

Q. How does air pollution affect the atmospheric processes?

Air is a critical part of the Earth’s environment, supporting life, regulating temperature, and enabling weather systems. However, in today’s world, the quality of air is being affected due to increasing levels of air pollution caused by human activities like industrialization, vehicle emissions, deforestation, and burning of fossil fuels.

Air pollution refers to the presence of harmful or excessive substances like carbon dioxide (CO₂), sulfur dioxide (SO₂), nitrogen oxides (NOx), ozone (O₃), particulate matter (PM), and volatile organic compounds (VOCs) in the atmosphere.

These pollutants not only harm human health but also disturb important atmospheric processes such as temperature regulation, rainfall, cloud formation, and overall climate balance.

1. Global Warming and Greenhouse Effect

• Air pollutants like carbon dioxide, methane (CH₄), and nitrous oxide (N₂O) are greenhouse gases.

• They trap the heat radiated from the Earth’s surface and prevent it from escaping into space.

• This leads to a gradual increase in Earth’s average temperature — a phenomenon known as global warming.

Impacts:

• Melting of glaciers and polar ice caps

• Rising sea levels

• Increased frequency of heatwaves, droughts, and wildfires

2. Changes in Weather and Climate Patterns

• Air pollution alters the natural climate cycles by affecting temperature, humidity, wind patterns, and precipitation.

• High levels of particulate matter and aerosols in the air can reflect sunlight back into space, causing cooling in some areas, while greenhouse gases cause warming in others.

• These imbalances lead to unpredictable weather such as erratic rainfall, intense storms, and cyclones.

Example:
The South Asian monsoon is becoming more irregular due to rising air pollution levels in the Indo-Gangetic Plain.

3. Disruption of Cloud Formation and Rainfall

• Particulate matter (dust, smoke, soot) acts as cloud condensation nuclei (CCN), which affect the size and number of water droplets in clouds.

• More aerosols lead to the formation of smaller cloud droplets, making it harder for them to combine and fall as rain.

• This delays or reduces rainfall and contributes to droughts and water scarcity.

Example:
Urban areas experience a phenomenon known as “urban drought”, where rainfall reduces despite cloud presence.

4. Formation of Smog and Temperature Inversions

• In urban and industrial areas, a mixture of pollutants like ozone, nitrogen dioxide, and VOCs combine with sunlight to form photochemical smog.

• In winters, a temperature inversion can occur, where a layer of warm air traps cooler air below, preventing pollutants from dispersing.

• This causes smog to accumulate near the surface, reducing visibility and causing health issues.

Example:
Delhi and other North Indian cities suffer severe smog every winter due to stubble burning, vehicular pollution, and inversion layers.

5. Acid Rain Formation

• Sulfur dioxide (SO₂) and nitrogen oxides (NOx) released from industries, vehicles, and power plants react with water vapor in the air to form sulfuric and nitric acid.

• These acids come down with rainwater as acid rain.

Effects of Acid Rain:

• Damages crops, trees, and aquatic life

• Corrodes buildings and historical monuments (e.g., Taj Mahal)

• Changes soil chemistry, affecting plant growth

6. Ozone Layer Depletion

• Certain air pollutants like chlorofluorocarbons (CFCs) and halons break down ozone (O₃) molecules in the stratosphere.

• This weakens the ozone layer, which protects us from the harmful ultraviolet (UV) rays of the Sun.

Consequences:

• Increase in skin cancer and eye problems in humans

• Disruption of marine ecosystems due to UV exposure

• Decreased crop productivity due to cellular damage in plants

7. Reduced Visibility and Atmospheric Transparency

• Airborne pollutants like dust, smoke, and soot particles scatter and absorb sunlight.

• This reduces visibility and makes the sky appear hazy or dull.

• In some regions, visibility drops to just a few meters, affecting transportation and public safety.

Example:
Heavy fog mixed with pollution in cities like Delhi, Beijing, and Lahore causes frequent air traffic disruptions.

8. Effects on Natural Carbon and Water Cycles

• Air pollution interferes with natural carbon sequestration by damaging forests and ocean systems.

• Acid rain and ozone damage reduce the ability of trees and algae to absorb CO₂.

• Pollution particles alter cloud structure, delaying precipitation and affecting the water cycle.

9. Urban Heat Island Effect (UHIE)

• Air pollution contributes to the Urban Heat Island effect, where cities become significantly warmer than surrounding rural areas.

• Pollution from vehicles, factories, and ACs traps heat in built-up areas.

• UHIE affects local weather and increases energy consumption for cooling, further worsening air quality.

10. Long-Term Climate Change

• Continuous emissions of pollutants, especially greenhouse gases, are causing climate change.

• This leads to:

  • Rising sea levels due to melting ice

  • Shifting climatic zones

  • Loss of biodiversity

  • Increased frequency of extreme events like floods, storms, and wildfires

Conclusion

Air pollution is not just a local issue; it has global effects on atmospheric processes. From warming the planet to disturbing rainfall patterns and damaging the ozone layer, the impacts are deep and far-reaching. It affects natural systems, weather cycles, human health, agriculture, and ecosystems.

To protect our atmosphere and the planet, we must:

• Reduce emissions from vehicles and industries

• Promote clean energy and afforestation

• Use public transport and eco-friendly products

• Spread awareness about environmental protection

Only through collective efforts can we ensure a cleaner, healthier, and more stable atmosphere for future generations.