Climate Change
Overview
Climate change is one of the most heavily tested topics in UPSC Prelims, appearing across environment, international relations, and current affairs sections. Questions frequently test your understanding of international agreements (UNFCCC, Kyoto, Paris), India's commitments, and the scientific basis of global warming. This topic bridges pure science with diplomacy and policy.
Mastery requires understanding the mechanism (greenhouse effect → warming → impacts), the institutional framework (UNFCCC and its protocols), and India's position (NDCs, Panchamrit pledges). Expect factual questions on specific targets, principles like "common but differentiated responsibilities," and recent IPCC findings. The topic also connects to renewable energy, biodiversity loss, and disaster management.
Key Concepts
- Greenhouse Effect: Natural process where atmospheric gases (CO₂, CH₄, N₂O, water vapour) trap outgoing infrared radiation, keeping Earth ~33°C warmer than it would otherwise be. Human activities have enhanced this effect.
- Global Warming vs Climate Change: Global warming refers specifically to rising average temperatures; climate change encompasses broader impacts—altered precipitation, sea-level rise, extreme weather events.
- Ocean Acidification: Oceans absorb ~25% of anthropogenic CO₂, forming carbonic acid. pH has dropped from 8.2 to ~8.1 since pre-industrial times (a 30% increase in acidity), threatening coral reefs and shellfish.
- Carbon Budget: The total amount of CO₂ that can still be emitted while limiting warming to 1.5°C or 2°C. IPCC estimates the remaining budget for 1.5°C is rapidly depleting.
- CBDR-RC Principle: "Common But Differentiated Responsibilities and Respective Capabilities"—developed nations bear greater historical responsibility and must lead in mitigation and finance.
- NDCs (Nationally Determined Contributions): Voluntary national climate action plans submitted under the Paris Agreement, reviewed every five years with a "ratchet mechanism" for increased ambition.
- Climate Finance: Developed countries committed to mobilising $100 billion annually (by 2020, extended to 2025) for developing nations' climate action; now being renegotiated toward a New Collective Quantified Goal.
- Mitigation vs Adaptation: Mitigation reduces emissions (renewable energy, efficiency); adaptation adjusts to impacts (flood defences, drought-resistant crops). Both are essential.
Formulas / Key Facts
| Fact | Detail |
|---|---|
| Pre-industrial CO₂ level | ~280 ppm |
| Current CO₂ level (2024) | ~420 ppm |
| Paris Agreement temperature goal | Limit warming to well below 2°C, pursue 1.5°C |
| Kyoto Protocol commitment periods | CP1: 2008–2012; CP2: 2013–2020 |
| UNFCCC adoption/entry into force | Adopted 1992 (Rio); entered into force 1994 |
| India's per capita emissions | ~2.4 tonnes CO₂/year (global avg ~4.7) |
| Major GHGs by warming potential | CO₂ (1), CH₄ (28–36), N₂O (265–298) over 100 years |
| Ocean pH change | From 8.2 to ~8.1 (30% more acidic) |
| IPCC established | 1988 by WMO and UNEP |
Worked Examples
Example 1: A question states: "Which of the following are greenhouse gases? 1. Carbon dioxide 2. Nitrogen 3. Methane 4. Ozone"
Solution: Nitrogen (N₂) is not a greenhouse gas—it neither absorbs nor emits infrared radiation significantly. CO₂, CH₄, and O₃ (tropospheric ozone) are GHGs. Answer: 1, 3, 4 only.
Example 2: "Consider the following statements about the Paris Agreement:
- It replaced the Kyoto Protocol entirely.
- It follows a bottom-up approach through NDCs.
- It is legally binding in terms of emission reduction targets.
Which statements are correct?"
Solution: Statement 1 is incorrect—Paris builds upon the UNFCCC framework; Kyoto's second commitment period ran until 2020. Statement 2 is correct—countries determine their own NDCs. Statement 3 is partially misleading—while the Paris Agreement is legally binding as a treaty, the specific emission targets within NDCs are not legally binding (only procedural aspects are). Answer: Only 2 is fully correct.
Example 3: "What are India's Panchamrit pledges announced at COP26?"
Solution: Five commitments—(1) 500 GW non-fossil energy capacity by 2030; (2) 50% energy from renewables by 2030; (3) Reduce total projected carbon emissions by 1 billion tonnes by 2030; (4) Reduce carbon intensity of economy by 45% by 2030; (5) Achieve net-zero by 2070.
Common Mistakes
- Confusing Kyoto's binding targets with Paris's voluntary NDCs → Kyoto imposed legally binding targets on Annex I (developed) countries; Paris has universal participation but nationally determined, non-binding targets.
- Thinking UNFCCC is an agreement with specific targets → UNFCCC is the parent framework convention (1992) that established the Conference of Parties (COP) system; Kyoto and Paris are protocols/agreements under it with specific commitments.
- Assuming India has no binding commitments → While NDC targets aren't legally binding internationally, India has incorporated several targets into national policy and updated its NDCs in 2022.
- Mixing up Annex I and Non-Annex I under Kyoto → Annex I = developed countries with binding targets; Non-Annex I = developing countries (including India, China) with no binding Kyoto targets.
- Overlooking ocean acidification as separate from warming → Ocean acidification is a direct chemical consequence of CO₂ absorption, distinct from (though related to) temperature-driven ocean warming.
Quick Reference
- UNFCCC (1992) → Framework; Kyoto (1997) → Binding targets for developed; Paris (2015) → Universal NDCs, 1.5/2°C goal
- India's Net-Zero target: 2070 (announced COP26, Glasgow)
- IPCC AR6 (2021–2023): Confirmed human influence "unequivocal"; 1.5°C likely breached by early 2030s
- COP meets annually; major recent COPs: Paris (21), Glasgow (26), Sharm el-Sheikh (27), Dubai (28)
- GWP ranking: SF₆ > HFCs > N₂O > CH₄ > CO₂
- Loss and Damage Fund: Operationalised at COP28 (2023) for climate-vulnerable nations