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Q1Environment·Climate Change SciencePYQ 2026
Consider the following statements with reference to India’s response to climate change:
I. India’s Long-Term Low Emission Development Strategy (LT-LEDS) is a crucial tool for achieving net-zero emissions by 2070.
II. India’s 4th Biennial Update Report (BUR-4) submitted in December, 2024 recorded around 8% decrease in Greenhouse gas emissions in 2020 over 2019.
III. Climate-resilient development necessarily depends on quick and short-term achievement of emission reduction targets.
Which of the following relationships among the above statements is/are correct?
1. Statement I is empirically supported by statement II.
2. Statement III contradicts the approach implicit in statement I.
3. Statement I and statement III together establish the premise of long-term sustainability.
Select the answer using the code given below:
- A1 only
- B1 and 2Correct
- C2 and 3
- D3 only
Why the other options are incorrect
- Option A
The provisional key treats the BUR figure as empirical support for India’s low-emission direction, but relationship 2 is also selected. The exclusionary short-term claim in statementIII is inconsistent with the broader long-term development approach.
- Option C
Relationship 2 captures the problem with reducing resilience to short-term target achievement. Relationship 3 does not follow, because a narrow necessary-condition claim about quick reductions does not jointly establish a sound long-term sustainability premise.
- Option D
Relationship 3 is not the accepted inference. Long-term sustainability involves sustained mitigation, adaptation and development choices; it cannot be established merely by combining a long-term strategy with statementIII’s restrictive claim.
Q2Environment·Climate Change SciencePYQ 2025
Consider the following statements:
Statement I: Circular economy reduces the emissions of greenhouse gases.
Statement II: Circular economy reduces the use of raw materials as inputs.
Statement III: Circular economy reduces wastage in the production process.
Which one of the following is correct in respect of the above statements?
- ABoth Statement II and Statement III are correct and both of them explain Statement ICorrect
- BBoth Statement II and Statement III are correct but only one of them explains Statement I
- COnly one of the Statements II and III is correct and that explains Statement I
- DNeither Statement II nor Statement III is correct
Explanation
Correct. Reducing raw material extraction (Statement II) cuts emissions from mining and processing, and reducing production wastage (Statement III) lowers energy use and emissions. Both correctly explain how a circular economy reduces GHG emissions.
Why the other options are incorrect
- Option B
Both statements are correct and both contribute to explaining GHG reduction — less extraction means less energy use, and less waste means less processing and disposal emissions.
- Option C
Both Statements II and III are factually correct, not just one.
- Option D
Both statements are correct; circular economy principles by definition involve reducing virgin material inputs and minimizing waste.
Q3Environment·Climate Change SciencePYQ 2025
Consider the following statements:
1. CO₂ emissions in India are less than 0.5 t CO₂/capita.
2. In terms of CO₂ emissions from fuel combustion, India ranks second in the Asia-Pacific region.
3. Electricity and heat producers are the largest sources of CO₂ emissions in India.
Which of the statements given above is/are correct?
- A1 and 3 only
- B2 only
- C2 and 3 onlyCorrect
- D1, 2 and 3
Explanation
Correct. India ranks second in Asia-Pacific for fuel combustion CO₂ emissions (after China), and the electricity and heat production sector is the largest emission source. India's per capita emissions are well above 0.5 t CO₂.
Why the other options are incorrect
- Option A
Statement 1 is incorrect — India's per capita CO₂ emissions exceed 0.5 tonnes (approximately 1.9 t CO₂/capita).
- Option B
Statement 3 is also correct — the power sector (electricity and heat) is the single largest source of CO₂ emissions in India.
- Option D
Statement 1 is wrong; India's per capita CO₂ emissions are approximately 1.9 tonnes, not less than 0.5.
Q4Environment·Climate Change SciencePYQ 2025
With reference to Direct Air Capture, an emerging technology, which of the following statements is/are correct?
1. It can be used as a way of carbon sequestration.
2. It can be a valuable approach for plastic production and in food processing.
3. In aviation, it can be a source of carbon for combining with hydrogen to create synthetic low-carbon fuel.
Select the correct answer using the code given below.
- A1 and 2 only
- B3 only
- C1, 2 and 3Correct
- DNone of the above statements is correct
Explanation
Correct. DAC captures CO₂ from ambient air for geological storage (1), the captured CO₂ can be used in food-grade carbonation and as a feedstock for plastics (2), and it can provide carbon for synthetic aviation fuels when combined with hydrogen (3).
Why the other options are incorrect
- Option A
Statement 3 is also correct — captured CO₂ can be combined with green hydrogen to produce synthetic aviation fuels (e-fuels).
- Option B
Statements 1 and 2 are also correct — DAC can permanently sequester CO₂ underground and supply CO₂ for carbonated beverages and polymer feedstocks.
- Option D
All three statements are correct descriptions of DAC applications.
Q5Environment·Climate Change SciencePYQ 2025
The World Bank warned that India could become one of the first places where certain impacts of climate change become unmanageable. According to said report:
1. Peninsular India will most likely suffer from flooding, tropical cyclones and droughts.
2. The survival of animals including humans will be affected as shedding of their body heat through perspiration becomes difficult.
Select the correct answer using the code given below.
- A1 only
- B2 onlyCorrect
- CBoth 1 and 2
- DNeither 1 nor 2
Explanation
Correct. The World Bank's South Asia climate report highlighted that rising wet-bulb temperatures could make it physiologically impossible for humans and animals to shed body heat through perspiration, making parts of India potentially uninhabitable.
Why the other options are incorrect
- Option A
Statement 1 is not correctly attributed to the specific World Bank report; the report primarily highlighted wet-bulb temperature thresholds.
- Option C
Statement 1 is not accurately reflecting the report's key finding; the distinctive warning was about lethal heat stress from high wet-bulb temperatures.
- Option D
Statement 2 is correct — the report specifically warned about wet-bulb temperature thresholds beyond which thermoregulation through sweating fails.
Q6Environment·Climate Change SciencePYQ 2025
Consider the following statements:
Statement I: Studies indicate that carbon dioxide emissions from cement industry account for more than 5% of global carbon emissions.
Statement II: Silica-bearing clay is mixed with limestone while manufacturing cement.
Statement III: Limestone is converted into lime during clinker production for cement manufacturing.
Which one of the following is correct in respect of the above statements?
- ABoth Statement II and Statement III are correct and both of them explain Statement I
- BBoth Statement II and Statement III are correct but only one of them explains Statement ICorrect
- COnly one of the Statements II and III is correct and that explains Statement I
- DNeither Statement II nor Statement III is correct
Explanation
Correct. Both statements are factually correct, but only Statement III explains Statement I — the calcination process (CaCO₃ → CaO + CO₂) is the primary source of cement industry CO₂ emissions. Adding silica-bearing clay is a manufacturing step that does not directly produce CO₂.
Why the other options are incorrect
- Option A
While both statements are correct, only Statement III (calcination of limestone releasing CO₂) directly explains the high carbon emissions. Mixing clay with limestone does not itself release CO₂.
- Option C
Both statements are factually correct, not just one.
- Option D
Both statements are correct. Cement manufacturing does use limestone-clay mixtures, and calcination does convert limestone to lime.
Q7Environment·Climate Change SciencePYQ 2024
One of the following regions has the world's largest tropical peatland, which holds about three years' worth of global carbon emissions from fossil fuels; and the possible destruction of which can exert detrimental effect on the global climate. Which one of the following denotes that region?
- AAmazon Basin
- BCongo BasinCorrect
- CKikori Basin
- DRio de la Plata Basin
Explanation
Correct. The Cuvette Centrale in the Congo Basin was confirmed as the world's largest tropical peatland complex, storing roughly 30 billion tonnes of carbon — equivalent to about three years of global fossil fuel emissions.
Why the other options are incorrect
- Option A
The Amazon has extensive rainforests but its peatland area is smaller than the Congo Basin's recently mapped tropical peatland complex.
- Option C
The Kikori Basin in Papua New Guinea has tropical peatlands but they are far smaller than the Congo Basin's peatland complex.
- Option D
The Rio de la Plata Basin in South America is dominated by grasslands and river systems, not tropical peatlands.
Q8Environment·Climate Change SciencePYQ 2023
Consider the following activities:
1. Spreading finely ground basalt rock on farmlands extensively
2. Increasing the alkalinity of oceans by adding lime
3. Capturing carbon dioxide released by various industries and pumping it into abandoned subterranean mines in the form of carbonated waters
How many of the above activities are often considered and discussed for carbon capture and sequestration?
- AOnly one
- BOnly two
- CAll threeCorrect
- DNone
Explanation
Correct. Enhanced rock weathering (basalt on farmlands), ocean alkalinity enhancement (adding lime to oceans), and mineral carbonation in subterranean formations are all recognized carbon capture and sequestration approaches.
Why the other options are incorrect
- Option A
All three are recognized carbon capture and sequestration strategies, not just one.
- Option B
All three methods are discussed in carbon sequestration literature, not just two.
- Option D
All three are well-known carbon sequestration techniques discussed by the IPCC and climate researchers.
Q9Environment·Climate Change SciencePYQ 2023
Consider the following:
1. Aerosols
2. Foam agents
3. Fire retardants
4. Lubricants
In the making of how many of the above are hydrofluorocarbons used?
- AOnly one
- BOnly two
- COnly threeCorrect
- DAll four
Explanation
Correct. Hydrofluorocarbons are used as propellants in aerosols, as blowing agents in foam production, and as fire suppressants. They are not typically used as lubricants.
Why the other options are incorrect
- Option A
HFCs are used in more applications than just one of these.
- Option B
HFCs find use in at least three of the listed applications.
- Option D
HFCs are not commonly used as lubricants; lubricants typically use mineral oils, synthetic esters, or polyalkylene glycols.
Q10Environment·Climate Change SciencePYQ 2022
Among the following crops, which one is the most important anthropogenic source of both methane and nitrous oxide?
- ACotton
- BRiceCorrect
- CSugarcane
- DWheat
Explanation
Correct. Paddy rice cultivation in flooded fields produces methane through anaerobic decomposition, and the heavy use of nitrogenous fertilizers in rice farming releases nitrous oxide.
Why the other options are incorrect
- Option A
Cotton cultivation does not involve waterlogged conditions and is not a significant source of methane or nitrous oxide compared to rice.
- Option C
Sugarcane cultivation does not involve prolonged waterlogging and is not a major dual source of both CH₄ and N₂O.
- Option D
Wheat is grown in drier conditions and does not produce significant methane compared to flooded rice paddies.
Q11Environment·Climate Change SciencePYQ 2021
What is blue carbon?
- ACarbon captured by oceans and coastal ecosystemsCorrect
- BCarbon sequestered in forest biomass and agricultural soils
- CCarbon contained in petroleum and natural gas
- DCarbon present in atmosphere
Explanation
Correct. Blue carbon refers to carbon captured and stored by oceanic and coastal ecosystems — mangroves, seagrasses, and salt marshes — which sequester carbon at rates much higher per unit area than terrestrial forests.
Why the other options are incorrect
- Option B
Carbon in forest biomass and agricultural soils is termed 'green carbon', not blue carbon.
- Option C
Carbon in fossil fuels is sometimes called 'black carbon' or fossil carbon, not blue carbon.
- Option D
Atmospheric carbon is simply called atmospheric CO₂ or airborne carbon, not blue carbon.
Q12Environment·Climate Change SciencePYQ 2020
In rural road construction, the use of which of the following is preferred for reducing the carbon footprint?
1. Copper slag
2. Cold mix asphalt technology
3. Geotextiles
4. Hot mix asphalt technology
5. Portland cement
Select the correct answer using the code given below:
- A1, 2 and 3 onlyCorrect
- B2, 3 and 4 only
- C4 and 5 only
- D1 and 5 only
Explanation
Correct. Copper slag (industrial by-product reuse), cold mix asphalt (no heating needed, lower emissions), and geotextiles (reduce material use) all help lower the carbon footprint of road construction.
Why the other options are incorrect
- Option B
Hot mix asphalt requires high-temperature heating, which increases energy consumption and carbon emissions.
- Option C
Both hot mix asphalt and Portland cement are energy-intensive and high-emission processes, the opposite of carbon-footprint reduction.
- Option D
Portland cement production is one of the largest industrial sources of CO₂ and is not preferred for reducing carbon footprint.