Unit 12: Global Environmental Issues & Ethics
1. Global Warming and Greenhouse Effect
Global warming is the unusually rapid increase in Earth’s average surface temperature over the past century primarily due to the greenhouse gases released as people burn fossil fuels.
- Greenhouse Gases (GHGs): Carbon dioxide (CO2), Methane (CH4), Nitrous oxide (N2O), and water vapor.
- Consequences: Melting of polar ice, rising sea levels, and unpredictable weather patterns (extreme heatwaves, floods).
2. Ozone Layer Depletion
The ozone layer in the stratosphere absorbs most of the sun's harmful ultraviolet (UV) radiation. Depletion of this layer allows more UV radiation to reach the Earth's surface.
- Cause: Use of Chlorofluorocarbons (CFCs) in refrigerators, air conditioners, and aerosol sprays.
- Effects: Skin cancer, cataracts in humans, and damage to terrestrial and aquatic plant life.
3. Acid Rain and its Impacts
Acid rain occurs when emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx) react with water molecules in the atmosphere to produce acids.
- Sources: Burning of coal and oil in power plants and exhaust from motor vehicles.
- Impacts: Leaching of soil nutrients, damage to aquatic life in lakes, and corrosion of buildings/statues (e.g., the Taj Mahal).
4. Environmental Ethics: Issues and Solutions
Environmental ethics is the part of philosophy that studies the moral relationship of human beings to the environment.
Major Philosophical Views:
- Anthropocentrism: Humans are the most important species and nature is for our use.
- Biocentrism: All living beings have intrinsic value.
- Ecocentrism: The entire ecosystem, including non-living components, has moral value.
5. Future Sustainable Solutions
To address these global issues, the focus must shift towards sustainable practices:
- Renewable Energy: Transitioning from coal to solar, wind, and tidal energy.
- Circular Economy: Designing products to be reused or recycled indefinitely.
- Green IT: Developing energy-efficient hardware and optimizing software to reduce the carbon footprint of data centers.
6. Exam Focus Enhancements
Exam Tips
- The "Magic Year": Mention 1987 (Montreal Protocol) when discussing the Ozone layer and 2015 (Paris Agreement) for Global Warming.
- Taj Mahal Example: Always cite the "Yellowing of the Taj Mahal" as a classic local example of Acid Rain impact.
- Definitions: Be precise with terms like "Greenhouse Effect" vs "Global Warming"—one is the process, the other is the result.
Common Mistakes
- Confusing Gases: Don't say CO2 causes the ozone hole. CFCs cause the hole; CO2 causes the warming.
- Ozone Layer Location: Remember the "Good" ozone is in the **Stratosphere**, while "Bad" ozone (smog) is in the **Troposphere**.
- Ignoring Ethics: Students often think ethics are "fluff." In an LPU exam, ethical questions are frequently worth 5-10 marks.
Frequently Asked Questions
Q: Is the Greenhouse Effect naturally bad?
A: No, without the natural greenhouse effect, the Earth would be too cold to support life. The problem is the "enhanced" greenhouse effect caused by human activity.
Q: What is the main objective of the Paris Agreement?
A: To keep global temperature rise this century well below 2 degrees Celsius above pre-industrial levels.