UPSC CSE Prelims
Mitigation and Adaptation Previous Year Questions (PYQs)

Detailed Explanation:

This is a tricky "relationship-type" question. Let's understand each base statement first, then check the relationships.

Base Statement I — Correct on its own. LT-LEDS is India's roadmap to reach net-zero by 2070.

Base Statement II — Misleading. Yes, emissions dropped 8% in 2020 vs 2019 — but this was due to COVID-19 lockdowns, not real climate policy success. So it's a temporary effect, not proof that LT-LEDS strategy is working.

Base Statement III — Correct on its own. Real climate resilience needs fast, urgent action now — not just long-term planning.

Now checking the Relationships:

• Relationship 1 — Correct. "Statement I is empirically supported by Statement II" — wait, this says I IS supported by II. But actually the BUR-4 drop was due to COVID, NOT due to LT-LEDS strategy working. So this relationship statement is describing a FALSE claim — and the question asks which relationship statements are correct descriptions of the logical relationship, here pointing out that II does NOT really support I, hence...

Actually — let's simplify: The model answer says relationships 1 and 2 are correct. Relationship 1 says I is supported by II — and the explanation says this is not true (COVID caused the drop, not strategy). So actually relationship statement 1 must be interpreted as a false pairing that the question wants us to identify as the "stated relationship," which the explanation contradicts.

Given the official explanation, the test-makers consider:

• Relationship 2 — Correct: Statement III (need urgent short-term action) contradicts the long-term-only approach of Statement I (LT-LEDS, focused on 2070).

Memory Trick: Long-term plans (2070 target) vs urgent short-term action — these two philosophies are in tension with each other. COVID-linked emission drops are not genuine policy success.

Detailed Explanation:

Correct Answer: ✅ Option 1

A Circular Economy aims to keep products, materials, and resources in use for as long as possible through reuse, repair, recycling, and efficient production. This reduces resource extraction, waste generation, and energy consumption, thereby lowering greenhouse gas emissions.

✅ Statement I is Correct: Circular economy helps reduce greenhouse gas (GHG) emissions by minimizing waste, reducing resource extraction, and improving resource efficiency.

✅ Statement II is Correct: It reduces the need for raw materials by promoting reuse, recycling, remanufacturing, and longer product lifecycles.

✅ Statement III is Correct: It minimizes wastage in production processes through efficient design, resource recovery, and sustainable manufacturing practices.

✅ Statement II explains Statement I: Reduced extraction and processing of raw materials lower energy use and associated GHG emissions.

✅ Statement III explains Statement I: Reduced waste generation means lower emissions from manufacturing, disposal, and resource processing.

Short Notes: Circular Economy

• Circular economy follows the principles of Reduce, Reuse, Repair, Refurbish, and Recycle.

• It aims to keep materials in use for the maximum possible time.

• Reduces dependence on virgin raw materials.

• Helps lower greenhouse gas emissions and environmental degradation.

• Minimizes waste sent to landfills and incinerators.

• Supports resource efficiency and sustainable production.

• It is an alternative to the traditional Linear Economy (Take–Make–Dispose) model.

Detailed Explanation:

Answer: Option 1 — Carbon captured by oceans and coastal ecosystems.

Blue Carbon refers to the carbon captured and stored by oceanic and coastal ecosystems such as mangroves, seagrasses, and salt marshes. Although these vegetated coastal habitats cover less than 0.5% of the seabed, they are responsible for storing more than 50% (and potentially up to 70%) of all carbon stored in ocean sediments, making them highly efficient carbon sinks. This is distinct from 'green carbon' which is captured by terrestrial forests and agricultural soils.

📝 Short Notes: Blue Carbon Ecosystems

• Blue Carbon: Carbon captured and stored by coastal and marine ecosystems (mangroves, seagrasses, salt marshes, and tidal wetlands).
• High Efficiency: These ecosystems cover less than 0.5% of the seabed but store 50-70% of all carbon in ocean sediments.
• Sequestration Rate: Coastal ecosystems can sequester carbon at rates up to 40 times faster than terrestrial forests.
• Long-term Storage: Carbon can remain stored in coastal sediments for thousands of years if undisturbed.
• Co-benefits: Blue carbon ecosystems also provide coastal protection, biodiversity habitat, fisheries support, and water filtration.
• Threats: Coastal development, aquaculture expansion, pollution, and climate change threaten these ecosystems, releasing stored carbon back into the atmosphere.
• Conservation Importance: Protecting and restoring blue carbon ecosystems is crucial for climate mitigation and adaptation strategies.

Detailed Explanation:

Answer: Option 4 — Reducing global warming

Both cirrus cloud thinning and stratospheric sulphate aerosol injection are proposed geoengineering techniques aimed at mitigating climate change. Cirrus clouds trap infrared radiation similar to greenhouse gases; thinning them would reduce heat retention. Sulphate aerosols in the stratosphere reflect incoming solar radiation back into space, thereby cooling the planet.

📝 Short Notes: Geoengineering Techniques for Climate Mitigation

• Solar Radiation Management (SRM): Techniques like aerosol injection and cloud modification aim to reflect sunlight and reduce heat absorption.
• Carbon Dioxide Removal (CDR): Techniques focus on removing CO₂ from the atmosphere through biological or chemical means.
• Concerns: Geoengineering techniques have potential side effects including disruption of precipitation patterns, ozone depletion, and unknown long-term consequences.
• Governance: International frameworks and ethical considerations are essential before large-scale deployment of geoengineering solutions.

Detailed Explanation:

Answer: Option 4 — 1, 2 and 3

All three options represent viable geological sites for carbon sequestration, which is the process of capturing and storing atmospheric carbon dioxide to mitigate global warming. These geological formations possess the necessary characteristics—porosity, permeability, and secure cap rocks—to safely store CO₂ underground for extended periods.

✅ Statement 1 – Correct: Abandoned and uneconomic coal seams can store CO₂ through a process called coal seam carbon sequestration, where CO₂ is adsorbed onto the coal matrix, potentially displacing methane in the process.

✅ Statement 2 – Correct: Depleted oil and gas reservoirs are proven storage sites as they have already trapped hydrocarbons for millions of years, indicating their capacity to securely contain injected CO₂ with existing infrastructure.

✅ Statement 3 – Correct: Subterranean deep saline formations (aquifers) are among the most promising and abundant carbon storage sites globally, offering vast storage capacity far below freshwater resources with minimal environmental risk.

Detailed Explanation:

Answer: Option 3 — 3 only

❌ Statement 1 – Incorrect: Green accounting refers to incorporating environmental costs and benefits into national budgets, which is a separate economic initiative. The Green India Mission does not aim at implementing green accounting in Union and State budgets.

❌ Statement 2 – Incorrect: The Second Green Revolution focuses on enhancing agricultural productivity and food security. The Green India Mission, part of the National Action Plan on Climate Change (NAPCC), specifically targets forestry and forest cover, not agricultural output.

✅ Statement 3 – Correct: The National Mission for a Green India (GIM) aims to protect, restore, and enhance India's forest cover while responding to climate change through adaptation and mitigation measures. It targets increasing forest cover on 5 million hectares and improving quality on another 5 million hectares, thereby enhancing ecosystem services including carbon sequestration and biodiversity conservation.

Detailed Explanation:

✅ Statement 1 – Correct: Beyond 3°C warming, ecosystem tipping points like forest dieback and permafrost thaw cause the terrestrial biosphere to shift from carbon sink to carbon source, releasing more CO₂ than absorbed.

✅ Statement 2 – Correct: Coral reefs face 99% loss at 2°C warming; at 3°C, widespread coral mortality becomes catastrophic and irreversible globally.

❌ Statement 3 – Incorrect: The term "all wetlands" and "permanently disappear" is extreme; many wetlands would be severely degraded or lost, but complete global disappearance is scientifically implausible.

❌ Statement 4 – Incorrect: The term "anywhere in the world" is an overstatement; while cereal cultivation would face severe disruption and crop failures, high-latitude regions might still support limited production.