About this previous year paper
SCIENCE AND POLICY OF CLIMATE CHANGE (EEV021)
Section-wise Solved Answers & Notes
SECTION – A (10 × 2 = 20 Marks)
Very short & precise answers
(a) Climate change
Climate change refers to long-term changes in average temperature, rainfall, wind patterns, and other climatic conditions of the Earth, mainly due to natural causes and human activities.
(b) Energy balance
Energy balance is the balance between incoming solar radiation and outgoing heat energy from the Earth back into space.
(c) Greenhouse effect
The greenhouse effect is the process by which greenhouse gases trap heat in the Earth’s atmosphere, keeping the planet warm.
(d) Greenhouse gases
Greenhouse gases are atmospheric gases that absorb infrared radiation.
Examples:
• Carbon dioxide (CO₂) • Methane (CH₄)
• Nitrous oxide (N₂O) • Water vapour
• Ozone
(e) Influence of greenhouse gases on models
Greenhouse gases increase radiative forcing, leading to higher temperature predictions in climate models and altering circulation patterns.
(f) Polar model (short note)
Polar model explains cold air movement from polar regions toward lower latitudes, influencing global wind circulation and temperature distribution.
(g) Types of circulation models • Hadley circulation
• Ferrel circulation • Polar circulation
(h) Radiation (short note)
Radiation is the transfer of energy in the form of electromagnetic waves. Solar radiation heats the Earth, while terrestrial radiation cools it.
(i) Hadley vs Polar model
| Hadley Model | Polar Model |
|---|---|
| Operates near equator | Operates near poles |
| Warm air rises | Cold air sinks |
| Causes trade winds | Causes polar easterlies |
(j) Emissivity
Emissivity is the ability of a surface to emit thermal radiation compared to a perfect black body.
SECTION – B (Attempt Any Five)
(10 × 5 = 50 Marks)
(a) Nature of storms, cyclones & hurricanes
Storms are intense atmospheric disturbances involving strong winds, rain, thunder, or snow.
Cyclones:
• Form over warm ocean waters • Rotate counter-clockwise (Northern Hemisphere)
Hurricanes:
• Strong tropical cyclones • Wind speed > 119 km/h
• Cause flooding, wind damage, storm surge
(b) Paleo indicators of climate change
Paleo indicators provide evidence of past climate conditions.
Examples: • Ice cores – past temperature & CO₂
• Tree rings – rainfall & temperature • Ocean sediments – climate history
• Fossils – ancient ecosystems
(c) Effect of storm generation on ecosystem
• Destruction of forests and coral reefs • Soil erosion
• Loss of biodiversity • Flooding of wetlands
• Change in nutrient cycles
(d) Expected changes in storms due to warming
• Increased storm intensity • Higher rainfall
• More frequent extreme events • Increased coastal flooding
(e) Effects of global warming
• Rising sea level • Melting glaciers
• Heat waves • Changing rainfall patterns
• Loss of biodiversity
(f) Brief history of climate change
• Ice ages and interglacial periods • Industrial revolution increased CO₂
• Rapid warming observed after 1950 • Strong link to human activities
(g) Global warming & quantitative analysis
Global warming is the increase in Earth’s average temperature due to greenhouse gas emissions.
Quantitative indicators: • Global temperature rise (~1.1°C)
• CO₂ concentration (>420 ppm) • Sea-level rise (3–4 mm/year)
(h) Types of cyclones • Tropical cyclones
• Extra-tropical cyclones • Polar cyclones
SECTION – C (Attempt Any Two)
(15 × 2 = 30 Marks)
Q3. Role of United Nations (UN) in Climate Change
The UN plays a major role through:
• UNFCCC (1992) – Framework for climate action
• Kyoto Protocol (1997) – Emission reduction targets
• Paris Agreement (2015) – Limit global warming to below 2°C
• Climate finance & technology transfer
UN promotes global cooperation and sustainable development.
Q4. Mission of IPCC & Emission Restrictions
IPCC Mission
IPCC assesses: • Scientific basis of climate change
• Impacts and risks • Mitigation and adaptation options
International emission restrictions
• Kyoto Protocol • Paris Agreement
• Nationally Determined Contributions (NDCs) • Carbon trading & emission caps
Q5. Active federal legislation on climate change
Examples: • Clean Air Act (USA)
• Renewable energy policies • Emission standards for vehicles
• Energy efficiency regulations
Objectives:
• Reduce greenhouse gas emissions • Promote renewable energy
• Improve energy efficiency