Climate Change: UPSC Previous Year Questions (Environment and Ecology)

Explanation

Statement I is Correct: It is estimated that around 4-8 percent of the world’s carbon dioxide (CO₂) emissions come from the manufacture of cement, making it a major contributor to global warming

Statement II is correct but doesn’t explain statement I: Silica-bearing clay is mixed with limestone while manufacturing cement. Limestone, primarily composed of calcium carbonate (CaCO₃)₃), begins to decompose at temperatures around 825°C (1517°F). This process, called calcination, breaks down the limestone into calcium oxide (CaO) and carbon dioxide (CO₂). Thus the step of mixing Silica bearing clay and limestone contribute to the Carbon dioxide emission from cement industry.

Statement III is correct and explains Statement I: A significant portion of the emissions are an intrinsic part of the production of clinker. In the process of making cement clinker, limestone, which is primarily calcium carbonate (CaCO₃)₃), is heated to high temperatures (1450°C or 2640°F) in a kiln. This process, called calcination, decomposes the limestone into calcium oxide (CaO), commonly known as lime, and carbon dioxide (CO₂). The lime then reacts with other raw materials like clay and silica to form the clinker, which is the main ingredient in cement.

Explanation

COP 28 was held in Dubai, UAE in December 2023. It introduced the COP28 Declaration on Climate and Health to reduce health sector greenhouse gas emissions, enhance climate-resilient health systems, and address climate-related health risks like air pollution and extreme weather. $1 billion was pledged by entities like the Rockefeller Foundation and Green Climate Fund for climate-health initiatives.

Statement I is correct: India abstained from signing due to concerns over reducing greenhouse gas emissions from cooling systems critical for healthcare infrastructure, especially in remote areas. Highlighted that cooling systems for vaccines and medicines ensure healthcare resilience, and decarbonization could disrupt service delivery. This aligned with India’s G20 presidency (2023) focus on resilient healthcare.

Statement II is incorrect: The COP28 Declaration is non-binding, encouraging voluntary actions like assessing health sector emissions, developing action plans, and promoting low-carbon health systems, active mobility, and sustainable diets. It operates outside UNFCCC/Paris Agreement frameworks, not mandating decarbonization. India raised concerns about cooling-related emissions feasibility, not mandatory requirements.

Statement III is correct: India argued that decarbonizing the health sector, particularly cooling systems for vaccine storage and hospitals, could compromise healthcare resilience in tropical climates and remote areas. A Kenyan delegate noted India’s concern that emission reductions could hinder medical demands in underserved regions. India’s G20 priorities (2023) emphasized healthcare access, medical countermeasures, and digital health platforms, supported by its low per-capita emissions (<4% of global GHG emissions) and developing nation status.

Explanation

Article 6 of the Paris Agreement (2015, COP21) provides a framework for international cooperation to achieve climate goals through market-based and non-market-based mechanisms, enabling countries to meet their Nationally Determined Contributions (NDCs). It’s central to discussions on climate finance, GHG reduction, and SDG alignment.

Statement I is correct:

Article 6 is a cornerstone of the Paris Agreement, frequently discussed at COP summits--COP26 (Glasgow, 2021) and COP29 (Baku, 2024). It enables international cooperation for NDCs, addresses carbon markets and non-market approaches (NMAs), and mobilizes up to $1 trillion in climate finance by 2050. Highlighted by the World Bank and UNFCCC, it ensures environmental integrity and supports sustainable development. In India, with <4% of global GHG emissions, Article 6 is key in climate negotiations. Delays in rule finalization--e.g., COP25 (Madrid, 2019)--due to concerns like double counting underscore its importance.

Statement II is correct:

Article 6.2 allows bilateral trading of ITMOs with corresponding adjustments to avoid double counting. Article 6.4 sets up a UN-supervised Paris Agreement Crediting Mechanism (PACM), succeeding the Kyoto Protocol’s CDM, issuing A6.4ERs with 2% cancellation and 5% share for the Adaptation Fund. As per the World Bank and IISD, these rules--finalized at COP26 and advanced at COP29--enhance market integrity and climate finance. This explains Statement I, as carbon markets drive debates on market integrity, double counting, and private sector investment (e.g., $1 trillion potential by 2050).

Statement III is correct:

Article 6.8 promotes non-market approaches (NMAs) like tech transfers, policy coordination, and adaptation finance. Recognized by UNFCCC and Legal Response International, NMAs support equity, climate resilience, and SDGs, especially for nations like India, making Article 6 central in climate talks. This also explains Statement I, as NMAs address equity and cooperation, key topics in climate negotiations, especially for developing nations like India

Explanation

Direct Air Capture (DAC) is an emerging negative emission technology that extracts carbon dioxide (CO₂) directly from the atmosphere. It is gaining attention for its potential to mitigate climate change by enabling carbon sequestration, utilization in products, and synthetic fuel production

Statement I is correct:

DAC uses chemical processes with liquid solvents (e.g., potassium hydroxide) or solid sorbents to extract CO₂ from the atmosphere. Captured CO₂ is sequestered in deep geological formations like saline aquifers or depleted oil/gas reservoirs for permanent storage, preventing atmospheric release. As of 2024, 27 DAC plants capture about 0.01 Mt CO₂/year, with plans for 130 facilities targeting 65 Mt CO₂/year by 2030 (IEA Net Zero Emissions scenario). DACCS is critical for carbon dioxide removal (CDR), essential to limit warming to 1.5°C (NASA, IPCC). Especially important for hard-to-abate sectors (e.g., aviation). India’s low per-capita emissions (<4% global GHG) make DACCS a strategic offset tool.

Statement II is correct:

CO₂ is a feedstock for industrial uses:

Plastics production (polycarbonates, polyurethanes) locks CO₂ for decades to centuries, offering durable sequestration. Food processing: carbonation of beverages, modified atmosphere packaging, with a global CO₂ market of 230 Mt/year. WRI highlights CO₂ use in plastics/concrete as more durable than short-term uses like beverages. DAC CO₂ use supports India’s food processing sector (Make in India focus). Despite costs ($400-740/tCO), policy support (e.g., US 45Q tax credits) enhances viability.

Statement III is correct:

DAC CO₂ combined with renewable hydrogen produces synthetic kerosene (power-to-liquid fuels) via processes like Fischer-Tropsch. SAFs are drop-in fuels compatible with existing aircraft, helping decarbonize aviation. DACCU mitigates CO₂ and non-CO₂ effects (contrails). Costs currently $1.50-4.50/gallon, expected to fall by 2050. India emits about 2% global aviation GHG, potentially benefiting from SAF adoption to meet CORSIA goals.

Explanation

India, the third-largest global CO₂ emitter (2.8 Gt CO₂, 2023), has low per capita emissions (1.9-2.0 t CO₂/capita, 2022-2023) due to its 1.43 billion population (2022). Coal dominates power sector (75-76% electricity generation), followed by industry and transport.

Statement I is incorrect: Per capita CO₂ emissions measure annual emissions per person. IEA (2024) reports India’s at 2.0 t CO₂/capita (2023), Statista (2024) cites 1.89-2.0 t CO₂/capita (2022-2023), up from 1.79 t CO₂/capita (2021) due to economic growth and coal reliance. Our World in Data (2022) confirms 1.9 t CO₂/capita, below global average (4.6 t CO₂/capita) but above 0.5 t CO₂/capita. Worldometer (2022) notes 1.89 t CO₂/capita, historically 0.44 t (1980). Low emissions reflect large population and biomass use (13% lack electricity, Carbon Brief).

Statement II is correct: CO₂ emissions from fuel combustion (coal, oil, natural gas) reached 2.8 Gt CO₂ (2023, IEA), making India the second-largest emitter in Asia-Pacific after China (12.6 Gt CO₂). Emissions grew 7.2% (2023) due to coal-powered electricity (75% generation) and industrial growth (steel, cement).

Statement III is correct: Electricity and heat production, driven by coal-fired power plants (75% generation, 1,317 TWh, 2023, CEA Annual Report 2023-24), is India’s largest CO₂ source, contributing over 50% emission increase (1.4 Gt COe, Statista). Carbon intensity is 713 g CO₂/kWh, above global average (480 g CO₂/kWh). Industrial processes (cement, steel) and transport (oil-based) are secondary sources.

Explanation

Wet-bulb temperature is the lowest temperature that air can reach through the process of evaporation of water under current atmospheric conditions. It is measured by wrapping a thermometer bulb in a wet cloth and exposing it to air flow; as water evaporates from the cloth, it cools the thermometer, and the resulting temperature is the wet-bulb temperature.

Statement 1 is incorrect: Flooding, tropical cyclones and droughts in the Peninsular India are significant impacts of climate change. These are not the direct implications of the wet-bulb temperatures exceeding 35°C. The World Bank’s warning in its report titled Climate Investment Opportunities in India’s Cooling Sector, specifically relates to heat and humidity, not to hydrometeorological events like floods or cyclones.

Statement 2 is correct: This statement directly reflects the core implication of the World Bank’s report titled "Climate Investment Opportunities in India’s Cooling Sector". At wet-bulb temperatures above 35°C, humans and animals cannot cool themselves through sweating, leading to life-threatening conditions.