In the dynamic and ever-evolving landscape of the UPSC Civil Services Examination, the Environment and Ecology section has emerged as a kingmaker. With its significant and consistently high weightage in both Prelims and General Studies Paper 3, a strong command of this subject is non-negotiable for any serious aspirant. However, its vastness, encompassing everything from basic ecological concepts to complex international climate negotiations, often leaves students overwhelmed.
How do you navigate this vast ocean of information? How do you distinguish the ‘important’ from the ‘good to know’? This article is your strategic compass. We have meticulously analyzed a decade of UPSC question papers, tracked the latest trends in environmental news, and identified the core concepts that form the backbone of this subject. The result is a curated list of the 20 most crucial questions that you absolutely must master.
This is more than a Q&A list; it’s a comprehensive guide designed to build deep conceptual clarity and provide structured, Mains-ready answers. Here, you will find:
- A breakdown of the most vital topics in Ecology, Biodiversity, and Climate Change.
- Detailed, well-structured answers covering foundational concepts and current affairs.
- In-depth analysis of key environmental laws, international conventions, and policies.
- A practical and effective strategy to conquer the Environment syllabus.
Part 1: Ecology & Ecosystem Fundamentals
Q1. Differentiate between a Food Chain and a Food Web. Explain the 10% energy transfer law and its implications.
Answer:
• Food Chain: A linear sequence of organisms where nutrients and energy are transferred from one organism to another. It shows a single pathway of energy flow, e.g., Grass → Grasshopper → Frog → Snake.
• Food Web: A more realistic representation of an ecosystem, consisting of multiple interconnected food chains. It shows that most organisms feed on more than one type of organism, creating a complex web of interactions.
• Lindeman’s 10% Energy Transfer Law: This law states that during the transfer of energy from one trophic level to the next, only about 10% of the energy is stored as biomass and passed on. The remaining 90% is lost as metabolic heat.
Implications: This inefficient energy transfer is why food chains are typically limited to 4-5 trophic levels. There is simply not enough energy remaining at the top to support a larger population of apex predators. It also highlights why a vegetarian diet is more energy-efficient than a non-vegetarian one, as humans consuming plants (producers) are at a lower trophic level.
Q2. What is Ecological Succession? Differentiate between Primary and Secondary Succession.
Q3. Explain the concept of Eutrophication. What are its causes and consequences?
Q4. What are Ecological Pyramids? Explain why the pyramid of energy is always upright.
Part 2: Biodiversity & Conservation
Q5. Differentiate between in-situ and ex-situ conservation methods. Provide examples for each.
Answer: Both are methods of biodiversity conservation.
• In-situ Conservation (On-site): This involves protecting species within their natural habitats. It is the most ideal and holistic approach as it conserves the entire ecosystem and the evolutionary processes. This method is also more cost-effective for conserving a large number of species.
» Examples: National Parks, Wildlife Sanctuaries, Biosphere Reserves, Tiger Reserves, and Sacred Groves.
• Ex-situ Conservation (Off-site): This involves the conservation of species outside their natural habitats in a man-made environment. This is usually done for species that are critically endangered and cannot survive in their natural habitat due to extreme threats.
» Examples: Zoological Parks (Zoos), Botanical Gardens, Seed Banks, Gene Banks, and Cryopreservation (storing genetic material at very low temperatures).
Q6. What are Biodiversity Hotspots? What are the criteria for a region to be declared a hotspot, and name the hotspots in India.
Q7. What is the IUCN Red List? Explain the significance of key categories like Critically Endangered (CR), Endangered (EN), and Vulnerable (VU).
Q8. Discuss the key features and schedules of the Wildlife (Protection) Act, 1972.
Part 3: Climate Change & Global Action
Q9. Trace the evolution of global climate negotiations from the UNFCCC to the Paris Agreement. What is the core principle of the Paris Agreement?
Q10. What is the role of the Intergovernmental Panel on Climate Change (IPCC)? Why are its Assessment Reports significant?
Q11. Explain India’s Nationally Determined Contributions (NDCs) under the Paris Agreement, including the updated ‘Panchamrit’ targets.
Answer: NDCs are climate action plans submitted by each country under the Paris Agreement, outlining how they will reduce their emissions and adapt to climate impacts. India’s updated NDCs, known as ‘Panchamrit’ (five nectars), announced at COP26, are:
1. Non-Fossil Fuel Capacity: To increase India’s non-fossil fuel energy capacity to 500 Gigawatts (GW) by 2030.
2. Renewable Energy Share: To meet 50% of its energy requirements from renewable energy by 2030.
3. Emission Reduction: To reduce the total projected carbon emissions by one billion tonnes from now until 2030.
4. Emission Intensity: To reduce the carbon intensity of its economy by 45% by 2030, over 2005 levels.
5. Net Zero Target: To achieve the target of Net Zero emissions by the year 2070. These targets demonstrate India’s commitment to climate action while upholding the principle of ‘Common But Differentiated Responsibilities and Respective Capabilities’ (CBDR-RC).
Q12. What are Carbon Sequestration and Carbon Credits? How do they help in mitigating climate change?
Part 4: Environmental Pollution
Q13. Differentiate between primary and secondary air pollutants. Explain the formation of Photochemical Smog and its impact on health.
Q14. What are the key principles of the Solid Waste Management Rules, 2016? Discuss the concept of Extended Producer Responsibility (EPR).
Q15. What is Ocean Acidification? Explain its causes and its devastating impact on marine ecosystems, especially coral reefs.
Q16. What is plastic pollution? Discuss the significance and challenges of the plastic waste management rules in India.
Part 5: Environmental Laws & Conventions
Q17. The Environment (Protection) Act, 1986 is considered an “umbrella” legislation. Explain why.
Q18. Discuss the purpose and key provisions of the Forest Rights Act (FRA), 2006.
Q19. Explain the objectives of the following international conventions: Ramsar Convention, CITES, and Bonn Convention.
Answer:
• Ramsar Convention (1971): It is an intergovernmental treaty for the conservation and wise use of wetlands and their resources. Its mission is to halt the worldwide loss of wetlands and to conserve those that remain. Wetlands designated as internationally important are called Ramsar Sites.
• CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora, 1973): Its primary objective is to ensure that international trade in specimens of wild animals and plants does not threaten their survival. It subjects international trade in selected species to certain controls through a licensing system (Appendices I, II, III).
• Bonn Convention (Convention on the Conservation of Migratory Species of Wild Animals, 1979): It aims to conserve terrestrial, aquatic, and avian migratory species throughout their range. It is the only global convention specializing in the conservation of migratory species, their habitats, and their migration routes.
Q20. What is the National Green Tribunal (NGT)? Discuss its role and significance in environmental justice in India.
Strategy: How to Conquer Environment for UPSC
Mastering Environment requires a smart and integrated approach:
- Build a Strong Foundation: Start with the relevant chapters from NCERT Science textbooks (Classes 7-10) and the Class 12 Biology textbook (last four chapters on Ecology).
- One Standard Reference Book: Choose one standard book like ‘Environment’ by Shankar IAS or a similar reputed source and use it as your base reference.
- Newspaper is Non-Negotiable: This subject is highly dynamic. Read a quality newspaper (The Hindu/Indian Express) daily. Focus on news related to climate change (COP meetings), new species discoveries, pollution reports, and government policies.
- Government Reports & Websites: Keep an eye on the websites of the Ministry of Environment, Forest and Climate Change (MoEFCC) and reports like the India State of Forest Report (ISFR).
- Solve PYQs Religiously: Analyzing Previous Year Questions is the single best way to understand the demand of the exam and the type of questions asked.
Frequently Asked Questions (FAQs)
1. Is a science background necessary for the Environment section?
Not at all. UPSC tests general understanding, application, and awareness, not specialized scientific knowledge. A non-science student can score exceptionally well with a dedicated and strategic approach.
2. How to remember the details of so many international conventions?
Create a table. For each convention, note down: 1) The Year, 2) The Core Objective (e.g., Wetlands, Migratory Species), 3) Whether it’s legally binding, and 4) India’s status (signatory/ratified). Regular revision is key.
3. What is the weightage of Environment in UPSC Prelims?
The weightage has been consistently high. You can expect anywhere from 15 to 20+ questions from Environment and Ecology, often including questions that overlap with Geography and Agriculture, making it one of the most crucial subjects for clearing the Prelims cut-off.
Conclusion: The Environment section is not just a part of the syllabus; it’s a reflection of the most pressing challenges facing our planet today. A thorough understanding of these issues is vital for a future administrator. By focusing on these core themes, building strong conceptual foundations, and staying updated with current affairs, you can turn this subject into a high-scoring asset. Embrace the challenge, stay curious, and you will be well on your way to success.