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?

(d) Neither Statement II nor Statement III is correct

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?

(d) Neither Statement II nor Statement III is correct

Consider the following statements: Statement I. At the 28th United Nations Climate Change Conference (COP28), India refrained from signing the 'Declaration on Climate and Health'. Statement II. The COP28 Declaration on Climate and Health is a binding declaration; and if signed, it becomes mandatory to decarbonize health sector. Statement III. If India's health sector is decarbonized, the resilience of its health-care system may be compromised. Which one of the following is correct in respect of the above statements?

(d) Neither Statement II nor Statement III is correct

Consider the following statements: Statement I. Article 6 of the Paris Agreement on climate change is frequently discussed in global discussions on sustainable development and climate change. Statement II. Article 6 of the Paris Agreement on climate change sets out the principles of carbon markets. Statement III. Article 6 of the Paris Agreement on climate change intends to promote inter-country non-market strategies to reach their climate targets. Which one of the following is correct in respect of the above statements?

(d) Neither Statement II nor Statement III is correct

With reference to ‘Direct Air Capture’, an emerging technology, which of the following statements is/are correct? I. It can be used as a way of carbon sequestration. II. It can be a valuable approach for plastic production and in food processing. III. 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.

(d) None of the above statements is correct

Consider the following statements: Statement-I. The European Parliament approved The Net-Zero Industry Act recently. Statement-II. The European Union intends to achieve carbon neutrality by 2040 and therefore aims to develop all of its own clean technology by that time. Which one of the following is correct in respect of the above statements?

(a) Both Statement-I and Statement-II are correct and Statement-II explains Statement-I

(b) Both Statement-I and Statement-II are correct, but Statement-II does not explain Statement-I

(d) Statement-I is incorrect, but Statement-II is correct

Consider the following statements: Statement-I. Carbon markets are likely to be one of the most widespread tools in the fight against climate change. Statement-II. Carbon markets transfer resources from the private sector to the State. Which one of the following is correct in respect of the above statements?

(a) Both Statement-I and Statement-II are correct and Statement-II is the correct explanation for Statement-I

(d) Statement-I is incorrect but Statement-II is correct

(b) Carbon sequestered in forest biomass and agricultural soils

(c) Carbon contained in petroleum and natural gas

(d) Carbon present in atmosphere

Environment & ecology

Prelims · Environment & ecology · 53 questions

Climate change & agreements

Every UPSC Prelims question on this topic, 2016–2026, newest first. Tap an option to check yourself; the answer and explanation open below it.

Asked in 11 of 11 years · most in 2016 (6)

UPSC syllabus: “General issues on Environmental ecology, Bio-diversity and Climate Change - that do not require subject specialization.” See the full syllabus →

Showing 1–30 of 53, newest first.

Prelims 2026 · Q21

Medium Provisional key

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:

Answer & explanation

Answer: (b) 1 and 2

India's LT-LEDS (submitted to the UNFCCC in November 2022) lays out a gradual, long-horizon path to net-zero by 2070, and BUR-4 reported that national emissions in 2020 fell 7.93 per cent from 2019, which is data consistent with that path. Statement III's stress on quick, short-term targets runs against the long-term logic of statement I, so the two cannot together form a premise of long-term sustainability.

✓ 1. BUR-4 records that total GHG emissions including LULUCF fell by 7.93 per cent in 2020 over 2019, a measured figure that gives empirical backing to the net-zero pathway of statement I (though the 2020 fall was partly due to the pandemic).
✓ 2. The LT-LEDS works toward 2070 through low-carbon development 'in accordance with national circumstances', a long-term, phased approach; insisting on quick short-term cuts contradicts it.
✗ 3. Because statement III is at odds with statement I, the two cannot jointly establish a premise of long-term sustainability.

Remember · LT-LEDS (Nov 2022, COP27): pathway to net-zero by 2070. BUR-4 (Dec 2024): 2020 emissions 2,437 MtCO2e with LULUCF, down 7.93% from 2019.

Sources

India's Long-Term Low-Carbon Development Strategy, submitted to the UNFCCC (MoEFCC, 2022) ↗ “India will strive towards net-zero by 2070 through low carbon development in accordance with national circumstances.”
India: Fourth Biennial Update Report to the UNFCCC (MoEFCC, 2024) ↗ “Total national GHG emissions (including LULUCF) have decreased by 7.93 per cent with respect to 2019 and increased by 98.34 per cent since 1994”

Question and answer: UPSC's provisional GS Paper I (2026, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2026 · Q23

Easy Provisional key

Which of the following best explain(s) the rationale for protecting mangrove ecosystems in the context of climate resilience?

1.Mangroves reduce tidal energy and store freshwater, making them ideal sites for paddy cultivation in saline estuarine belts.
2.Their salt-sensitive roots filter seawater, making mangroves key to converting coastal land into freshwater aquaculture zones.
3.By withstanding tidal surges and offering biomass resources, mangroves function both as natural bio-shields and livelihood bases for rural communities.

Select the answer using the code given below:

Answer & explanation

Answer: (d) 3 only

Mangroves are salt-tolerant forests of tidal creeks and estuaries that absorb the force of storm surges and tsunami waves while supplying fuelwood, fish and other products to coastal people. They are neither freshwater stores for paddy nor salt-sensitive filters for freshwater fish farming; clearing them for such uses actually weakens coastal resilience.

✗ 1. Mangroves grow in saline tidal water and do not store freshwater; converting them to paddy fields removes the very buffer that protects the coast.
✗ 2. Mangrove species are salt-tolerant, not salt-sensitive, and their value lies in standing forest, not in turning coasts into freshwater aquaculture ponds.
✓ 3. Along with beaches and dunes, mangroves absorb the destructive force of storm and tsunami waves, and they provide wood, fuel and fisheries that support coastal livelihoods.

Remember · Mangroves: salt-tolerant tidal forests; natural bio-shields against cyclones and tsunamis, carbon sinks and livelihood sources. India has about 4,992 sq km of mangroves.

📘 Read it in NCERT: Class 11 Fundamentals of Physical Geography, Ch 6 (practise this chapter) · Class 11 India: Physical Environment, Ch 5 (practise this chapter) · Class 8 Curiosity, Ch 12 (practise this chapter)

Sources

NCERT Class 11 · Fundamentals of Physical Geography, Chapter 6 “Then come the barriers, beaches, beach dunes and mangroves, if any, to absorb the destructive force of storm and tsunami waves.”
NCERT Class 11 · India: Physical Environment, Chapter 5 “They consist of a number of salt-tolerant species of plants. Crisscrossed by creeks of stagnant water and tidal flows, these forests give shelter to a wide variety of birds.”
NCERT Class 8 · Curiosity, Chapter 12 “The Sundarbans protect us by slowing down strong winds and waves during storms and floods.”

Question and answer: UPSC's provisional GS Paper I (2026, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2026 · Q40

Hard Provisional key

Which one of the following is the first Plan Vivo certified Reducing Emissions from Deforestation and Forest Degradation (REDD+) project in India?

Answer & explanation

Answer: (c) Khasi Hills Community REDD+ project

The Khasi Hills Community REDD+ Project in East Khasi Hills, Meghalaya, is the project the Plan Vivo Foundation describes as India's first community-based REDD+ programme. It began in 2011 and is run with community groups and certified under Plan Vivo.

✓ (c) Plan Vivo's own project page calls the Khasi Hills Community REDD+ Project India's first community-based REDD+ programme. It protects and restores 27,000 ha of cloud forest in East Khasi Hills, Meghalaya, with 86 community groups taking part.
✗ (d) Plan Vivo, the certifying body, gives the 'India's first' description to the Khasi Hills project, so another project, including Sikkim Mamley Kamrang, cannot carry it.
✗ (a) Plan Vivo describes the Meghalaya project (option c) as India's first community-based REDD+ programme, so the Uttarakhand project is not the first.

Remember · Khasi Hills Community REDD+ Project (East Khasi Hills, Meghalaya): India's first community-based REDD+ programme, started 2011 and certified under Plan Vivo.

Sources

Plan Vivo Foundation: Khasi Hills Community REDD+ Project, India ↗ · reference work “The Khasi Hills Community REDD+ Project is India’s first community-based REDD+ programme and protects and restores 27,000 ha of cloud forest, in addition to preserving sacred groves and watersheds.”

Question and answer: UPSC's provisional GS Paper I (2026, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 1 Oct 2026 (how we verify). Permalink ·

Prelims 2026 · Q45

Easy Provisional key

Which of the following statements with regard to Green Hydrogen is/are correct?

1.It is decarbonized hydrogen obtained from natural gas reforming combined with carbon capture and storage (CCS).
2.It is produced using electrolysis of water with electricity generated by renewable energy.
3.National Green Hydrogen Mission of India aims for abatement of nearly 50 MMT of annual greenhouse gas emissions by 2030.

Select the answer using the code given below:

Answer & explanation

Answer: (b) 2 and 3 only

Green hydrogen is made by splitting water with electricity from renewable sources. Hydrogen made from natural gas or coal with carbon capture is a different colour, blue hydrogen. The National Green Hydrogen Mission does list nearly 50 MMT of annual greenhouse gas abatement among its targets.

✗ 1. Hydrogen from natural gas or coal combined with carbon capture (CCS/CCU) is blue hydrogen, not green.
✓ 2. Electrolysis of water run on renewable electricity is the definition of green hydrogen; its carbon intensity depends on how clean the power is.
✓ 3. The Mission's stated outcomes for 2030 include abatement of nearly 50 MMT of annual greenhouse gas emissions, alongside 5 MMT a year of green hydrogen capacity.

Remember · Green = electrolysis + renewable power. Blue = fossil gas/coal + carbon capture. Grey = fossil gas/coal without capture. NGHM 2030: 5 MMT/yr, about 50 MMT emissions abated.

Sources

PIB Explainer: National Hydrogen Mission (January 2023): green hydrogen ↗ “Green Hydrogen: It is produced using electrolysis of water with electricity generated by renewable energy. … Blue Hydrogen: It is produced via natural gas or coal gasification combined with carbon capture storage (CCS) or carbon capture use (CCU) technologies to reduce carbon emissions. … Cumulative reduction in fossil fuel imports over Rs. One lakh crore Abatement of nearly 50 MMT of annual greenhouse gas emissions”

Question and answer: UPSC's provisional GS Paper I (2026, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2026 · Q92

Easy Provisional key

A bond whose proceeds are used only to finance or refinance a combination of both environmental and social projects is called:

Answer & explanation

Answer: (c) Sustainability Bond

The label depends on what the proceeds fund. Green bonds fund environmental projects, social bonds fund social projects, and a sustainability bond funds a combination of both green and social projects.

✓ (c) Sustainability bonds apply proceeds exclusively to finance or re-finance a combination of green and social projects.
✗ (a) A green bond finances projects with clear environmental benefits only.
✗ (b) A social bond finances projects that address a specific social issue or achieve positive social outcomes, not a combination of environmental and social projects.
✗ (d) ‘Sovereign’ describes the issuer (a government), not the use of proceeds.

Remember · Use of proceeds decides the label: green = environment, social = social outcomes, sustainability = both together.

Sources

World Bank Treasury, IBRD Sustainable Development Bonds ↗ “World Bank Sustainable Development Bonds support the financing of a combination of green and social, i.e. “sustainable development”, projects, programs, and activities in member countries.”
ICMA: Green, Social and Sustainability Bonds, a high-level mapping to the SDGs (June 2019) ↗ · reference work “Sustainability Bonds are any type of bond instrument where the proceeds will be exclusively applied to finance or re-finance a combination of green and social projects … Green Bonds are any type of bond instrument where the proceeds will be exclusively applied to finance or re-finance projects with clear environmental benefits … Social Bonds finance projects that directly aim to address or mitigate a specific social issue and/or seek to achieve positive social outcomes, especially but not exclusively for a target population(s).”

Question and answer: UPSC's provisional GS Paper I (2026, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 1 Oct 2026 (how we verify). Permalink ·

Prelims 2025 · Q9

Easy

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?

Answer & explanation

Answer: (a) Both Statement II and Statement III are correct and both of them explain Statement I

A circular economy keeps materials in use through reuse, repair and recycling instead of the 'take–make–dispose' model. Using fewer fresh raw materials cuts the energy spent extracting and processing them, and cutting waste cuts the emissions from producing and disposing of it, so both II and III explain the fall in greenhouse gas emissions.

✓ Statement-I The European Parliament lists a reduction in total annual greenhouse gas emissions among the benefits of a circular economy.
✓ Statement-II Reusing and recycling products slows the use of natural resources, so fewer virgin raw materials are needed; this lowers emissions from mining and processing.
✓ Statement-III Better design and efficient production reduce waste and the energy and resources consumed, which also lowers emissions.

Remember · Circular economy = reduce, reuse, repair, recycle. Fewer raw materials and less waste mean less energy use and lower greenhouse gas emissions.

Sources

European Parliament, Circular economy: definition, importance and benefits (2023) ↗ “Parliament wants Europeans to switch to a circular economy by using raw materials more efficiently and reducing waste. … Another benefit from the circular economy is a reduction in total annual greenhouse gas emissions. Creating more efficient and sustainable products from the start would help to reduce energy and resource consumption”

Question and answer: UPSC's official GS Paper I (2025, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2025 · Q29

Easy

Consider the following statements:

I.Without the atmosphere, temperature would be well below freezing point everywhere on the Earth's surface.
II.Heat absorbed and trapped by the atmosphere maintains our planet's average temperature.
III.Atmosphere's gases, like carbon dioxide, are particularly good at absorbing and trapping radiation.

Which of the statements given above are correct?

Answer & explanation

Answer: (c) I, II and III

All three describe the natural greenhouse effect. The Earth's surface re-radiates sunlight as infrared heat; gases such as carbon dioxide, methane and water vapour absorb much of it, which keeps the global average near 15°C. Remove that blanket and the surface would be about 33°C colder, below freezing.

✓ I Without the atmosphere's greenhouse effect the average surface temperature would fall by roughly 33°C, from about 15°C to around −18°C, too cold for life.
✓ II The heat that the atmosphere absorbs and traps is what holds the planet's average temperature at a life-supporting level.
✓ III Carbon dioxide, methane and water vapour absorb the infrared heat re-radiated by the surface and stop it escaping to space.

Remember · Natural greenhouse effect: CO2, CH4, water vapour trap outgoing infrared; keeps Earth ≈ 15°C instead of ≈ −18°C (a 33°C difference).

📘 Read it in NCERT: Class 9 Exploration, Ch 13 (practise this chapter)

Sources

NCERT Class 9 · Exploration, Chapter 13 “Greenhouse gases like CO2, CH4 and water vapour absorb this re-radiated heat, preventing it from escaping into space. Without the atmosphere, the Earth would be too cold for life to survive.”
NASA Science: What is the greenhouse effect? ↗ “If carbon dioxide were removed, the terrestrial greenhouse effect would collapse, and Earth's surface temperature would drop significantly, by approximately 33°C (59°F). … Part of what makes Earth so amenable is its natural greenhouse effect, which maintains an average temperature of 15 ° C (59 ° F) .”

Question and answer: UPSC's official GS Paper I (2025, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2025 · Q31

Medium

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?

Answer & explanation

Answer: (b) Both Statement II and Statement III are correct but only one of them explains Statement I

Cement is among the largest single industrial sources of carbon dioxide, about 7% of global emissions according to the International Energy Agency. Both manufacturing facts are true, but only Statement III explains the emissions: heating limestone (calcium carbonate) to make lime releases carbon dioxide directly, on top of the fuel burnt in the kiln. Mixing silica-bearing clay with limestone is simply part of the recipe.

✓ Statement I The International Energy Agency puts the cement sector's share of global carbon dioxide emissions at about 7%, which is well above 5%.
✓ Statement II Cement needs limestone plus silica and alumina, which come mainly from clay or shale; this is true but does not by itself produce the carbon dioxide.
✓ Statement III In the kiln, calcium carbonate breaks down into calcium oxide (lime) and carbon dioxide; this 'process emission' is the main reason cement is so carbon-intensive, so III explains I.

Remember · Cement CO2 is about 7% of global emissions (IEA); most comes from calcination (CaCO3 → CaO + CO2) in clinker making, the rest from kiln fuel.

📘 Read it in NCERT: Class 10 Science, Ch 1 (practise this chapter) · Class 10 Contemporary India – II, Ch 6 (practise this chapter)

Sources

International Energy Agency: Cement technology roadmap plots path to cutting CO2 emissions 24% by 2050 (copy of the IEA news page) ↗ “The cement sector is the third-largest industrial energy consumer in the world, responsible for 7% of industrial energy use, and the second industrial emitter of carbon dioxide, with about 7% of global emissions.”
NCERT Class 10 · Science, Chapter 1 “Decomposition of calcium carbonate to calcium oxide and carbon dioxide on heating is an important decomposition reaction used in various industries. Calcium oxide is called lime or quick lime. It has many uses – one is in the manufacture of cement.”
NCERT Class 10 · Contemporary India – II, Chapter 6 “This industry requires bulky and heavy raw materials like limestone, silica and gypsum.”

Question and answer: UPSC's official GS Paper I (2025, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2025 · Q32

Hard

Consider the following statements:

Statement I: At the 28th United Nations Climate Change Conference (COP28), India refrained from signing the 'Declaration on Climate and Health'.
Statement II: The COP28 Declaration on Climate and Health is a binding declaration; and if signed, it becomes mandatory to decarbonize health sector.
Statement III: If India's health sector is decarbonized, the resilience of its health-care system may be compromised.

Which one of the following is correct in respect of the above statements?

Answer & explanation

Answer: (c) Only one of the Statements II and III is correct and that explains Statement I

India is not among the signatories of the COP28 UAE Declaration on Climate and Health (Dubai, December 2023); the list on the COP28 site goes from Iceland straight to Indonesia. The declaration is a political declaration whose commitments are made 'according to our national circumstances', so Statement II is wrong.

✓ Statement I India did not sign: the list of signatories on the COP28 site names 151 signatories, including the European Union, and India is not among them. The declaration was launched on COP28's inaugural Health Day, 3 December 2023.
✗ Statement II The declaration is not a mandate: its signatories commit to better integrating health into climate policy and to promoting steps such as assessing health-system emissions and developing action plans and decarbonisation targets, all 'according to our national circumstances'. Signing does not make decarbonising the health sector mandatory.
✓ Statement III UPSC's official key treats this as correct; we could not confirm India's stated reason from an official source, so we do not explain it here.

Remember · COP28 (Dubai, 2023) Declaration on Climate and Health: first Health Day at a COP, 151 signatories; India is not on the list. Commitments are 'according to our national circumstances', not mandatory.

Sources

COP28 UAE Presidency: COP28 UAE Declaration on Climate and Health ↗ · reference work “To achieve these aims - according to our national circumstances - we commit to pursuing the better integration of health considerations into our climate policy processes, … Promoting steps to curb emissions and reduce waste in the health sector, such as by assessing the greenhouse gas emissions of health systems, and developing action plans, nationally determined decarbonization targets, … 54. Hungary 55. Iceland 56. Indonesia 57. Iran 58. Iraq 59. Ireland 60. Israel 61. Italy”
WHO: COP28 UAE Declaration on climate and health ↗ “In a historic milestone marking the inaugural Health Day at the 28th UN Climate Change Conference (COP28), global leaders united in endorsing the health and climate change declaration,”

Question and answer: UPSC's official GS Paper I (2025, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 1 Oct 2026 (how we verify). Permalink ·

Prelims 2025 · Q34

Medium

Consider the following statements:

Statement I: Article 6 of the Paris Agreement on climate change is frequently discussed in global discussions on sustainable development and climate change.
Statement II: Article 6 of the Paris Agreement on climate change sets out the principles of carbon markets.
Statement III: Article 6 of the Paris Agreement on climate change intends to promote inter-country non-market strategies to reach their climate targets.

Which one of the following is correct in respect of the above statements?

Answer & explanation

Answer: (a) Both Statement II and Statement III are correct and both of them explain Statement I

Article 6 is the Paris Agreement's provision on voluntary cooperation between countries. It covers market approaches (carbon-market rules) and non-market approaches, so II and III are both true. Because it is the Agreement's route for cross-border carbon trading and other cooperation, it features regularly in climate and sustainable-development talks, which is what Statement I says; II and III explain that.

✓ Statement I Article 6 deals with international cooperation on carbon markets and non-market approaches, so it is a regular subject in climate and sustainable-development negotiations.
✓ Statement II Article 6.2 lays down the principles for voluntary cooperative approaches that transfer mitigation outcomes between countries (sustainable development, environmental integrity, transparency, robust accounting), and 6.4 sets up a mechanism for emission reductions.
✓ Statement III Article 6.8 recognises non-market approaches that help countries implement their nationally determined contributions, and 6.9 defines a framework to promote them.

Remember · Article 6 of the Paris Agreement: 6.2 = voluntary cooperative approaches (internationally transferred mitigation outcomes), 6.4 = a mitigation mechanism under COP/CMA authority, 6.8 = non-market approaches.

Sources

UNFCCC: Paris Agreement (English text), Article 6.2 ↗ “Parties shall, where engaging on a voluntary basis in cooperative approaches that involve the use of internationally transferred mitigation outcomes towards nationally determined contributions, promote sustainable development and ensure environmental integrity and transparency … Parties recognize the importance of integrated, holistic and balanced non-market approaches being available to Parties to assist in the implementation of their nationally determined contributions, in the context of sustainable development and poverty eradication”

Question and answer: UPSC's official GS Paper I (2025, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2025 · Q35

Easy

Which one of the following launched the ‘Nature Solutions Finance Hub for Asia and the Pacific’?

Answer & explanation

Answer: (a) The Asian Development Bank (ADB)

The Asian Development Bank (ADB) launched the Nature Solutions Finance Hub for Asia and the Pacific at COP28 in Dubai on 4 December 2023. It aims to attract at least $2 billion into investment programmes that include nature-based solutions, especially from capital markets and private capital.

✓ (a) ADB's own news release calls it 'ADB's Nature Solutions Finance Hub for Asia and the Pacific' and says ADB launched it at COP28.
✗ (b) The Asian Infrastructure Investment Bank is a separate regional lender and is not the launcher of this hub, though it too works in the Asia-Pacific.
✗ (d) The IBRD (World Bank) did not launch this hub; the initiative belongs to ADB, as its own release says.

Remember · Nature Solutions Finance Hub for Asia and the Pacific: launched by ADB at COP28 (Dubai, 4 December 2023), aiming to draw at least $2 billion into nature-based solutions.

Sources

ADB news release: ADB and Partners Launch Nature Financing Initiative for Asia and the Pacific (4 December 2023) ↗ · reference work “The Asian Development Bank (ADB) today launched a Nature Solutions Finance Hub for Asia and the Pacific at COP28 which aims to attract at least $2 billion into investment programs that incorporate nature-based solutions”

Question and answer: UPSC's official GS Paper I (2025, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2025 · Q36

Medium

With reference to ‘Direct Air Capture’, an emerging technology, which of the following statements is/are correct?

I.It can be used as a way of carbon sequestration.
II.It can be a valuable approach for plastic production and in food processing.
III.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.

Answer & explanation

Answer: (c) I, II and III

Direct air capture (DAC) pulls CO2 straight out of ambient air. The captured CO2 can be stored underground, which removes it from the atmosphere, or used as a carbon feedstock for products such as food and beverages, chemicals and some plastics, and, combined with hydrogen, for synthetic aviation fuel. All three statements describe real uses.

✓ I Capturing CO2 from the air and storing it permanently removes it from the atmosphere; this is carbon removal by sequestration.
✓ II Air-captured CO2 can serve as a climate-neutral feedstock for a range of products, from food and beverages to chemicals, and some plastics are among the CO2-based products.
✓ III Air-captured CO2 combined with hydrogen is used to make synthetic hydrocarbon fuels, notably for aviation.

Remember · Direct air capture takes CO2 from ambient air: store it (carbon removal) or use it (food and beverages, chemicals, plastics, and synthetic fuels made with hydrogen).

Sources

IEA: Direct Air Capture: A key technology for net zero (2022), Abstract ↗ · reference work “Capturing CO2 directly from the air and permanently storing it removes the CO2 from the atmosphere, providing a way to balance emissions that are difficult to avoid … Air-captured CO2 can also be used as a climate-neutral feedstock to produce a range of products, from synthetic aviation fuels to food and beverages. … Early commercial efforts to develop synthetic aviation fuels using air-captured CO2 and hydrogen have started, reflecting the important role that these fuels could play”

Question and answer: UPSC's official GS Paper I (2025, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2025 · Q38

Medium

Consider the following statements:

I.Carbon dioxide (CO2) emissions in India are less than 0.5 t CO2/capita.
II.In terms of CO2 emissions from fuel combustion, India ranks second in Asia-Pacific region.
III.Electricity and heat producers are the largest sources of CO2 emissions in India.

Which of the statements given above is/are correct?

Answer & explanation

Answer: (c) II and III only

India emits about 2 tonnes of CO2 per person, four times the 0.5 t in Statement I. It is the world's third-largest emitter, behind China and the United States, so within Asia-Pacific it is second after China. Power and heat generation is the biggest emitting activity, so II and III are correct.

✗ I The IEA puts India's per capita emissions at around 2 tonnes, less than half the world average of 4.6 tonnes, but far above 0.5 t.
✓ II India is the third-largest source of global energy-related CO2 (after China and the US). China is the only bigger emitter in Asia-Pacific, which makes India second in the region.
✓ III India's own report to the UNFCCC shows energy industries (mainly electricity and heat generation) as the largest contributor within the energy sector, with a 56.53% share of the sector's 2020 emissions.

Remember · India's CO2: about 2 t per person (world about 4.6 t); third-largest emitter globally, second in Asia-Pacific after China; power and heat generation is the largest source.

Sources

IEA: CO2 Emissions in 2023 (per capita) ↗ · reference work “However, India’s per capita emissions remain very low, at around 2 tonnes, less than half the world average of 4.6 tonnes. … India surpassed the European Union to become the third largest source of global emissions in 2023.”
Government of India: India's Fourth Biennial Update Report to the UNFCCC (BUR-4), GHG inventory 2020 ↗ “Within the energy sector, energy industries are the largest contributor with a 56.53 per cent (12,65,328 GgCO2e) of total emissions”

Question and answer: UPSC's official GS Paper I (2025, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2025 · Q64

Medium

The World Bank warned that India could become one of the first places where wet-bulb temperatures routinely exceed 35 °C. Which of the following statements best reflect(s) the implication of the above-said report?

I.Peninsular India will most likely suffer from flooding, tropical cyclones and droughts.
II.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.

Answer & explanation

Answer: (c) Both I and II

UPSC's official answer: (c) · the answer UPSC accepted, and the one that counts in the exam

What we believe is right: (b)

Statement II is the direct implication. Wet-bulb temperature combines heat and humidity; 'as the wet-bulb temperature approaches your core temperature, you lose the ability to cool down' (NASA), and the World Bank treats 35 °C as the point where heat waves 'break the human survivability limit'.
Statement I is not an implication of that warning. The World Bank report (Climate Investment Opportunities in India's Cooling Sector, 2022) projects the 35 °C threshold for 'the Chota Nagpur Plateau and North-Eastern India', and nowhere mentions floods, tropical cyclones, droughts or peninsular India.
A warning about heat stress does not imply a forecast of flooding and cyclones for a different region, so a strict reading accepts II only: (b).
UPSC's key accepts both, presumably reading the warning as one face of climate change over India whose other faces are floods, cyclones and drought.

UPSC's key accepts both statements; the report itself supports only II, giving (b). In the exam, when the stem says 'best reflect(s) the implication' and 'Both' is offered, UPSC has accepted a broad climate-impact statement alongside the direct one; but know what the report actually says.

World Bank (2022): Climate Investment Opportunities in India's Cooling Sector, the warning ↗“Soon India could become one of the first places in the world to experience heat waves that break the human survivability limit”
World Bank (2022): Climate Investment Opportunities in India's Cooling Sector, where 35 °C is projected ↗“climate models project that these temperatures could exceed the survivability threshold (that is, 35°C) at a few locations in the Chota Nagpur Plateau and North-Eastern India under future climate scenarios”
NASA Science: Too Hot to Handle, how wet-bulb temperature stops the body cooling ↗“But as the wet-bulb temperature approaches your core temperature, you lose the ability to cool down.”

This box is Minimalist IAS's analysis, with its sources; it does not change UPSC's answer.

UPSC's key accepts both statements. Statement II is the direct implication: wet-bulb temperature combines heat and humidity, and as it nears the body's core temperature sweat can no longer evaporate fast enough to shed heat, so survival itself is threatened. Statement I is counted as the wider implication: the key reads the warning as a sign of a climate system under stress over India, whose other faces are flooding, tropical cyclones and drought.

✓ I UPSC's key counts this as an implication. The report's warning of routine 35 °C wet-bulb readings signals a warmer, moister atmosphere over India; the key reads the hazards that go with such warming — heavier rain and flooding, stronger cyclones on the peninsula's coasts, longer dry spells — as part of what the warning implies.
✓ II Wet-bulb temperature combines heat and humidity. Near the body's core temperature, sweat cannot evaporate enough to cool the body (NASA), and the World Bank treats 35 °C as that survivability threshold.

Remember · Wet-bulb temperature combines heat and humidity. Near 35 °C sweat cannot cool the body, so survival is at risk; the World Bank flagged India as an early case.

Sources

World Bank (2022): Climate Investment Opportunities in India's Cooling Sector ↗ “Soon India could become one of the first places in the world to experience heat waves that break the human survivability limit … climate models project that these temperatures could exceed the survivability threshold (that is, 35°C) at a few locations in the Chota Nagpur Plateau and North-Eastern India under future climate scenarios”
NASA Science: Too Hot to Handle: How Climate Change May Make Some Places Too Hot to Live ↗ “As long as the wet-bulb temperature is well below your skin temperature, your body can release heat to your surroundings through radiation and sweating. But as the wet-bulb temperature approaches your core temperature, you lose the ability to cool down.”

Question and answer: UPSC's official GS Paper I (2025, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 1 Oct 2026 (how we verify). Permalink ·

Prelims 2024 · Q16

Medium

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?

Answer & explanation

Answer: (b) Congo Basin

The Cuvette Centrale peatlands of the Congo Basin, spread across the Republic of Congo and the Democratic Republic of the Congo, form the world's largest tropical peatland. They lock away carbon equal to about three years of global greenhouse gas emissions, which would be released if the peat were drained or degraded.

✓ (b) The Congo Basin peat swamp forest stores around 29 billion tonnes of carbon, roughly three years of global emissions; the 2018 Brazzaville Declaration was signed to protect it.
✗ (a) The Amazon has peatlands too, but the single largest tropical peatland complex is the Congo Basin's Cuvette Centrale.
✗ (c) The Kikori Basin is a river basin in Papua New Guinea, rich in forest but not the world's largest tropical peatland.

Remember · Cuvette Centrale, Congo Basin: world's largest tropical peatland, ~29 billion tonnes of carbon ≈ three years of global emissions; Brazzaville Declaration (2018).

Sources

UNEP press release: Historic agreement signed to protect the world's largest tropical peatland ↗ “There is a lot at stake in the protection of these peatlands: the equivalent of three years of global greenhouse gas emissions are stored in the Congo Basin, emissions that could be released if the peatlands are degraded or the natural wetlands drained.”
UNEP story: Critical ecosystems — Congo Basin peatlands ↗ “The peat swamp forest of the Congo Basin stores around 29 billion tons of carbon – approximately equivalent to three years’ worth of global greenhouse gas emissions”

Question and answer: UPSC's official GS Paper I (2024, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2024 · Q26

Medium

Which one of the following is the correct description of "100 Million Farmers"?

Answer & explanation

Answer: (a) It is a platform for accelerating the transition towards food and water systems that are net-zero (carbon), nature-positive and that aims to increase farmer resilience.

100 Million Farmers is a World Economic Forum platform, launched in 2021, that brings companies, governments, farmer groups and financiers together to shift food and water systems to net-zero, nature-positive farming by 2030 while making farmers more resilient. The name refers to its goal of reaching 100 million farmers.

✓ (a) The WEF describes it as a multi-stakeholder platform for net-zero, nature-positive food systems by 2030 that backs local solutions, farmer incentives and resilience, including through regenerative and climate-smart practices.
✗ (b) An international network devoted to organic animal husbandry is a different body; 100 Million Farmers deals with climate and nature outcomes across farming, not organic livestock specifically.
✗ (d) Organising farmers into producer organisations for market access is a common policy tool, but it is not the purpose of this WEF climate-and-nature platform.

Remember · 100 Million Farmers = World Economic Forum platform (2021) for net-zero, nature-positive food and water systems and farmer resilience by 2030.

Sources

World Economic Forum: 100 Million Farmers, Breakthrough Models for Financing a Sustainability Transition (Insight Report, January 2024) ↗ · reference work “This implementation is part of the 100 Million Farmers platform, which accelerates sustainable agri-food practices and supports private and public sector leaders in collective action efforts that position food and farmers as central pillars of the global climate and nature agenda.”
Sustainability Magazine: 100 Million Farmers, the move to net-zero (2 May 2021) ↗ · reference work “The World Economic Forum has announced 100 Million Farmers, a platform moving towards “ Net-zero and nature-positive food systems by 2030 , ” which encourages “local solutions” as well as empowering farmers.”

Question and answer: UPSC's official GS Paper I (2024, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2024 · Q46

Medium

Consider the following materials:

1.Agricultural residues
2.Corn grain
3.Wastewater treatment sludge
4.Wood mill waste

Which of the above can be used as feedstock for producing Sustainable Aviation Fuel?

Answer & explanation

Answer: (c) 1, 2, 3 and 4

Sustainable Aviation Fuel is made from renewable, non-petroleum feedstocks, and the US Department of Energy's list of them names all four materials: agricultural residues, corn grain, wet waste such as wastewater treatment sludge, and wood mill waste.

✓ 1. Agricultural residues are named on the DOE list of SAF feedstocks. They are a typical waste-based biomass source.
✓ 2. Corn grain is also on the list. It is a starch crop, which is why it feeds ethanol-based routes to jet fuel. ICAO's India study notes that maize supplies part of India's ethanol, and that ethanol can be turned into jet fuel by the alcohol-to-jet route.
✓ 3. Wet wastes, specifically manures and wastewater treatment sludge, are listed as feedstocks. ICAO's India study also mentions sewage sludge as a wet waste that can be turned into biocrude for SAF.
✓ 4. Wood mill waste is on the list. ICAO's India study lists sawdust and bark from sawmills among forest-based SAF feedstocks.

Remember · SAF feedstocks are broad: crops such as corn, crop and forest residues, wood mill waste, municipal solid waste, wet waste such as sludge, and fats, oils and greases.

Sources

US Department of Energy (BETO), Sustainable Aviation Fuel: Reducing Emissions from Commercial Flight ↗ “These resources include corn grain; oil seeds; algae; other fats, oils, and greases; agricultural residues; forest harvesting residues; wood mill waste; municipal solid waste streams; wet wastes (manures, wastewater treatment sludge); and dedicated energy crops.”
US Department of Energy, Alternative Fuels Data Center: Sustainable Aviation Fuel ↗ “SAF can be produced from non-petroleum-based renewable feedstocks including, but not limited to, the food and yard waste portion of municipal solid waste, woody biomass, fats/greases/oils, and other feedstocks.”
ICAO (ACT-SAF), Feasibility Study on the Use of Sustainable Aviation Fuels in India (copy of the ICAO PDF) ↗ “Other types of residues include sawdust and bark generated at sawmills, tall oil, and black liquor from kraft pulping. … through hydrothermal liquefaction of wet wastes such as sewage sludge. … Sugarcane provides most ethanol production, with the remainder from food grains such as maize and surplus rice stocks determined by the Food Corporation of India.”

Question and answer: UPSC's official GS Paper I (2024, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2024 · Q96

Medium

Consider the following statements:

Statement-I: The European Parliament approved The Net-Zero Industry Act recently.
Statement-II: The European Union intends to achieve carbon neutrality by 2040 and therefore aims to develop all of its own clean technology by that time.

Which one of the following is correct in respect of the above statements?

Answer & explanation

Answer: (c) Statement-I is correct, but Statement-II is incorrect

Statement-I is correct: the European Parliament approved the Net-Zero Industry Act on 25 April 2024. Statement-II is wrong on two counts. The EU's goal is net-zero emissions by 2050, not 2040, and the Act aims for the EU to produce about 40% of its own annual needs for net-zero technologies by 2030, not all of them.

✓ Statement-I The European Parliament adopted the Act on 25 April 2024 by 361 votes to 121, with 45 abstentions. At that stage the Council still had to adopt it formally for it to become law.
✗ Statement-II The EU's climate target is a 55% cut in net emissions by 2030 and net-zero by 2050. The Act sets a target of 40% of annual deployment needs for net-zero technologies to be produced in Europe by 2030. It does not aim at making all clean technology in the EU.

Remember · EU Net-Zero Industry Act (Parliament vote 25 April 2024): target 40% of annual deployment needs of net-zero technologies made in the EU by 2030; EU climate neutrality target is 2050.

Sources

MEPs adopt plans to boost Europe's Net-Zero technology production (European Parliament press release, 25 April 2024) ↗ “On Thursday, Parliament approved the Net-Zero industry Act to bolster EU production in technologies needed for decarbonisation. … sets a target for Europe to produce 40% of its annual deployment needs in net-zero technologies by 2030”
Net Zero Industry Act: boosting clean technologies in Europe (European Parliament) ↗ “In 2030 net greenhouse gas emissions must be down by 55 percent as compared to 1990 levels, while by 2050, net emissions must come down to zero.”

Question and answer: UPSC's official GS Paper I (2024, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2023 · Q20

Medium

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?

Answer & explanation

Answer: (c) Only three

Hydrofluorocarbons (HFCs) replaced ozone-depleting CFCs and HCFCs in cooling, aerosol propellants, foam blowing and fire suppression. Lubricants are not an HFC application, so three of the four are correct.

✓ 1. HFCs serve as propellants in aerosol cans, one of the uses listed by the US EPA and UNEP.
✓ 2. HFCs are used as blowing agents to make insulating and other foams.
✓ 3. Some HFCs are used as fire-suppression (fire-extinguishing) agents, a replacement for ozone-depleting halons.
✗ 4. Lubricants are oils and greases; HFCs are gases used as refrigerants, propellants, blowing agents and fire suppressants, not as lubricants.

Remember · HFCs: refrigerants, AC, aerosols, foam blowing, fire suppression, solvents. Not ozone-depleting but potent greenhouse gases; phased down under the Kigali Amendment (2016).

Sources

US EPA, Background on HFCs and the AIM Act ↗ “HFCs are used in applications such as air conditioning, refrigeration, fire suppression, solvents, foam blowing agents, and aerosols.”
UNEP OzonAction, About the Montreal Protocol ↗ “HFCs are now widespread in air conditioners, refrigerators, aerosols, foams and other products. While these chemicals do not deplete the stratospheric ozone layer, some of them have high GWPs ranging from 12 to 14,000.”

Question and answer: UPSC's official GS Paper I (2023, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2023 · Q23

Hard

Consider the following statements:

Statement-I: Carbon markets are likely to be one of the most widespread tools in the fight against climate change.
Statement-II: Carbon markets transfer resources from the private sector to the State.

Which one of the following is correct in respect of the above statements?

Answer & explanation

Answer: (b) Both Statement-I and Statement-II are correct and Statement-II is not the correct explanation for Statement-I

Carbon markets put a price on each tonne of emissions and are spreading fast, from the EU's emissions trading system to India's Carbon Credit Trading Scheme (2023). When governments auction emission allowances, money does flow from companies to the State, but that revenue is a by-product; markets are popular because pricing carbon makes polluters cut emissions where it is cheapest.

✓ Statement-I Emissions trading and carbon-credit markets are among the most widely adopted climate policy tools; India notified its own Carbon Credit Trading Scheme in June 2023 to put a price on a tonne of CO2-equivalent.
✓ Statement-II Where allowances are auctioned, companies pay the government: EU ETS auctions raise revenue for national budgets and climate funds. This transfer is not why carbon markets are used, so Statement-II does not explain Statement-I.

Remember · Carbon market = cap (or intensity target) + tradable permits/credits → carbon gets a price. Auctioned permits raise public revenue. India: Carbon Credit Trading Scheme, 2023 (BEE administers).

Sources

Economic Survey 2023-24, Ch 6, Indian Carbon Market ↗ “The regulations on the Carbon Credit Trading Scheme (CCTS), also called the Indian Carbon Market, were notified by the Ministry of Power on 28 June 2023.”
European Commission, EU ETS: Auctioning ↗ “Auctioning of allowances in the EU ETS raises revenues for national budgets, the Innovation Fund, the Modernisation Fund and starting in 2026, the Social Climate Fund.”

Question and answer: UPSC's official GS Paper I (2023, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2023 · Q68

Medium

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?

Answer & explanation

Answer: (c) All three

All three activities are discussed as ways to capture and lock away carbon dioxide. Spreading crushed basalt (enhanced weathering) and adding lime to the sea (ocean alkalinity enhancement) are carbon-removal options assessed by the IPCC, and abandoned mines are listed among niche sites for underground CO2 storage.

✓ 1. Enhanced weathering spreads crushed silicate rock such as basalt on soil so that it reacts with atmospheric CO2. The IPCC cites estimates that spreading basalt on farmland in 12 countries could remove up to 2 GtCO2 a year by 2050.
✓ 2. Ocean alkalinity enhancement adds alkaline material such as lime to the sea so that it takes up and stores more CO2. The IPCC notes this idea goes back to a 1995 proposal to dissolve highly reactive lime in surface ocean water.
✓ 3. The IPCC's report on CO2 capture and storage names abandoned mines, along with basalts and salt caverns, as niche options for geological storage of captured CO2.

Remember · Enhanced weathering (crushed basalt on land), ocean alkalinity enhancement (lime in the sea) and storing captured CO2 underground, even in abandoned mines, are all discussed for carbon removal.

Sources

IPCC AR6 Working Group III, Chapter 12: enhanced weathering (Cross-sectoral Perspectives) ↗ “Beerling et al. (2020) estimate that up to 2 GtCO2 yr–1 could be removed by 2050 by spreading basalt onto 35–59% (weighted mean 53%) of agricultural land of 12 countries. … The use of enhanced ocean alkalinity for carbon storage was first proposed by Kheshgi (1995) who considered the creation of highly reactive lime that would readily dissolve in the surface ocean and sequester CO2.”
IPCC Special Report on Carbon Dioxide Capture and Storage, Chapter 5: Underground geological storage ↗ “Other geological media and/or structures – including basalts, oil or gas shale, salt caverns and abandoned mines – may locally provide niche options for geological storage of CO2.”

Question and answer: UPSC's official GS Paper I (2023, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2023 · Q99

Easy

Consider the following heavy industries:

1.Fertilizer plants
2.Oil refineries
3.Steel plants

Green hydrogen is expected to play a significant role in decarbonizing how many of the above industries?

Answer & explanation

Answer: (c) All three

All three. Green hydrogen, made by splitting water with renewable electricity, can replace the fossil-based hydrogen that fertilizer plants and refineries use today and the coal and coke that steel plants use for reducing iron ore. The Government of India names all three sectors in its National Green Hydrogen Mission.

✓ 1. Ammonia for nitrogenous fertilizers is made from hydrogen obtained from natural gas. Green hydrogen, or green ammonia made from it, can replace that and cut gas imports.
✓ 2. Refineries already use large amounts of hydrogen made from fossil fuels; swapping it for green hydrogen lowers a refinery's carbon footprint.
✓ 3. Hydrogen can replace coal and coke in iron and steel production, one of the biggest carbon-emitting industries; the Mission funds pilot projects for low-carbon steel.

Remember · Green hydrogen targets hard-to-abate sectors: fertilizer (green ammonia), refining, steel, and long-haul transport and shipping. India's mission aims at 5 MMT a year by 2030.

Sources

PIB, National Green Hydrogen Mission (NGHM) (Internet Archive copy) ↗ “Green Hydrogen has the potential to replace the utilization of imported fossil fuels across various sectors including fertilizer production, petroleum refining, the mobility sector, steel production and shipping propulsion applications.”
PIB, Explainer: National Hydrogen Mission (January 2023) ↗ “In industry, hydrogen can potentially replace the coal and coke in iron and steel production.”

Question and answer: UPSC's official GS Paper I (2023, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2022 · Q21

Easy

Among the following crops, which one is the most important anthropogenic source of both methane and nitrous oxide?

Answer & explanation

Answer: (b) Rice

Paddy is grown in standing water, and bacteria decomposing organic matter in that oxygen-free soil release methane; the heavy nitrogen fertiliser used on rice, poorly taken up by the plant, adds nitrous oxide. No other field crop contributes so much of both gases.

✓ (b) Flooded paddy fields are one of the largest human-made sources of methane (about a tenth of global methane emissions), and fertiliser applied to rice releases nitrous oxide as well.
✗ (d) Wheat is grown on drained, aerated soil, so it produces little methane; its fertiliser gives some nitrous oxide but not both gases on rice's scale.
✗ (c) Sugarcane is a heavy user of water and fertiliser, but it is not grown under continuous flooding, so it is not a major methane source.

Remember · Flooded rice = anaerobic soil = methane; nitrogen fertiliser = nitrous oxide. Alternate wetting and drying, SRI and direct-seeded rice cut paddy methane.

Sources

World Bank blog: Greening the rice we eat ↗ “significant greenhouse gas (GHG) emissions—methane, nitrous oxide (N 2 O) and carbon dioxide (CO 2 ) are byproducts of rice farming and the rice value chain. Rice is responsible for 10% of global methane emissions”
PIB: Measures to Reduce Methane Emissions (Ministry of Environment, Forest and Climate Change, 24 July 2023) ↗ “As per India’s third Biennial Update Report, India’s methane emissions in 2016 (excluding LULUCF) were 409 million tone CO 2 e of which, 73.96% was from Agriculture sector”

Question and answer: UPSC's official GS Paper I (2022, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2022 · Q22

Easy

"System of Rice Intensification" of cultivation, in which alternate wetting and drying of rice fields is practised, results in:

1.Reduced seed requirement
2.Reduced methane production
3.Reduced electricity consumption

Select the correct answer using the code given below:

Answer & explanation

Answer: (d) 1, 2 and 3

SRI transplants young seedlings singly at wide spacing and keeps the field moist rather than flooded. Fewer seedlings means far less seed; drying the soil between irrigations curbs methane-producing bacteria; and less irrigation means less pumping, so less electricity. All three follow.

✓ 1. Because one young seedling is planted per hill at wide spacing, SRI needs only a small fraction of the seed used in conventional transplanted rice.
✓ 2. Methane forms in oxygen-free, waterlogged soil. Alternate wetting and drying lets air into the soil, so methane emission falls; ICAR lists SRI among its methane-mitigation technologies for rice.
✓ 3. SRI uses roughly a fifth to a third less water than flooded paddy. Where fields are irrigated by electric pumps, less water pumped means lower electricity use.

Remember · SRI: young single seedlings, wide square spacing, moist (not flooded) soil, weeding that aerates the soil — less seed, less water, less methane, similar or higher yield.

Sources

FAO Science, Technology and Innovation Portal: System of rice intensification (SRI) ↗ “the rice growing areas can be extended using the same quantity of water (climate change adaptation). The technique requires less seed and fertiliser.”
PIB: Measures to Reduce Methane Emissions (Ministry of Environment, Forest and Climate Change, 24 July 2023) ↗ “has developed several technologies with mitigation potential for methane from rice viz. (a) System for Rice Intensification – The technique has potential to enhance rice yield from 36-49% with about 22-35% less water than conventional transplanted rice”

Question and answer: UPSC's official GS Paper I (2022, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2022 · Q41

Medium

"Climate Action Tracker" which monitors the emission reduction pledges of different countries is a:

Answer & explanation

Answer: (a) Database created by coalition of research organisations

The Climate Action Tracker is an independent research project run jointly by two research organisations, Climate Analytics and NewClimate Institute. It has assessed countries' climate pledges and actions since 2009 and belongs to no UN or treaty body.

✓ (a) It is a collaboration of two research organisations, Climate Analytics and NewClimate Institute, that compares each government's targets and policies with the Paris Agreement goal. UNEP's Emissions Gap Report itself uses it as one of the independent assessments.
✗ (b) The IPCC (properly the Intergovernmental Panel on Climate Change) assesses climate science for governments. The Tracker is a separate, independent project and not a wing of it.
✗ (c) It is not a committee of the UNFCCC, the climate treaty secretariat; it is an outside analysis that tracks what governments do.
✗ (d) It is not an agency promoted and financed by UNEP and the World Bank; UNEP only cites it, alongside other independent studies.

Remember · Climate Action Tracker: independent tracker of national climate pledges, run by Climate Analytics and NewClimate Institute since 2009. Not an IPCC, UNFCCC or UNEP body.

Sources

UNEP, Emissions Gap Report 2015, Annex B (Additional INDC assessment information) ↗ “The Climate Action Tracker has evaluated climate action proposals by countries since 2009.”
Climate Action Tracker, About (what is CAT?) ↗ · reference work “A collaboration of two organisations, Climate Analytics and NewClimate Institute, the CAT has been providing this independent analysis to policymakers since 2009.”

Question and answer: UPSC's official GS Paper I (2022, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 1 Oct 2026 (how we verify). Permalink ·

Prelims 2022 · Q42

Hard

Consider the following statements:

1."The Climate Group" is an international non-profit organization that drives climate action by building large networks and runs them.
2.The International Energy Agency in partnership with the Climate Group launched a global initiative "EP100".
3.EP100 brings together leading companies committed to driving innovation in energy efficiency and increasing competitiveness while delivering on emission reduction goals.
4.Some Indian companies are members of EP100.
5.The International Energy Agency is the Secretariat to the "Under2 Coalition".

Which of the statements given above are correct?

Answer & explanation

Answer: (b) 1, 3 and 4 only

Statements 1, 3 and 4 are correct. The Climate Group, not the International Energy Agency, launched EP100 and is the secretariat of the Under2 Coalition, so statements 2 and 5 fail.

✓ 1. The Climate Group is an international non-profit that describes its method as building and running networks of businesses and governments, such as EP100 and the Under2 Coalition.
✗ 2. EP100 was launched by The Climate Group in 2016 as an action of the We Mean Business coalition. The International Energy Agency did not launch it.
✓ 3. EP100 is a campaign inviting influential companies to pledge to double their energy productivity, that is, to get more economic output from each unit of energy used, which cuts emissions and raises competitiveness.
✓ 4. Mahindra & Mahindra, the tractor maker, joined EP100 in April 2016 and pledged to double its energy productivity by 2030.
✗ 5. The Climate Group has acted as secretariat of the Under2 Coalition, the network of state and regional governments, since 2015. The IEA holds no such role.

Remember · The Climate Group runs EP100 (energy productivity, business) and is secretariat of the Under2 Coalition (sub-national governments). Mahindra & Mahindra is an Indian member.

Sources

UNFCCC, Under2 Coalition press release, COP22 Marrakech (2016) ↗ “The Climate Group, an international non-profit that works with business, state and regional leaders to promote a prosperous, low-carbon future was announced as Secretariat of the Under2 Coalition at last year’s COP in Paris.”
The Climate Group, About us ↗ · reference work “We do this by building large and influential networks and holding organisations accountable, turning their commitments into action.”
The Climate Group, Under2 Coalition ↗ · reference work “Climate Group acts as the Under2 Coalition’s secretariat, supporting and accelerating collective climate ambition.”
Sustainable Energy for All, Businesses join new global campaign to boost energy productivity (The Climate Group press release, 11 May 2016) ↗ · reference work “The Climate Group launched a new global program on energy productivity - EP100 , an action of the We Mean Business coalition, at the Energy Efficiency Global Forum (EE Global) in Washington D.C. today … They join Mahindra & Mahindra Ltd. , the world’s largest manufacturer of tractors, who joined EP100 last month and pledged to double their energy productivity by 2030 on a baseline of 2008-2009. … EP100 is a global campaign to encourage the world’s most influential businesses to pledge to double their energy productivity, in order to get more economic output from each unit of energy input.”

Question and answer: UPSC's official GS Paper I (2022, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 1 Oct 2026 (how we verify). Permalink ·

Prelims 2022 · Q80

Easy

Which one of the following best describes the term “greenwashing”?

Answer & explanation

Answer: (a) Conveying a false impression that a company’s products are eco-friendly and environmentally sound

Greenwashing means misleading people into believing that a company or other entity is doing more for the environment than it really is. Option (a) says exactly this, in terms of a company's products.

✓ (a) It is a deceptive claim of environmental friendliness, for example labelling a product 'green' or 'eco-friendly' without real proof. The UN treats it as an obstacle to climate action because it promotes false solutions.
✗ (b) Leaving environmental costs out of a country's accounts is a gap in national accounting (green accounting), not greenwashing.
✗ (c) Ignoring ecological damage during infrastructure building is environmental negligence, not a false green claim.
✗ (d) Making provision for environmental costs in a project is a genuine safeguard, the opposite of misleading claims.

Remember · Greenwashing: a false or exaggerated claim that a company, product or policy is environmentally friendly; it misleads consumers and delays real climate action.

Sources

United Nations, Greenwashing: the deceptive tactics behind environmental claims ↗ “By misleading the public to believe that a company or other entity is doing more to protect the environment than it is”

Question and answer: UPSC's official GS Paper I (2022, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2021 · Q19

Easy

What is blue carbon?

Answer & explanation

Answer: (a) Carbon captured by oceans and coastal ecosystems

'Blue carbon' is the carbon taken up and stored by the ocean and by coastal ecosystems such as mangroves, tidal marshes and seagrass meadows. Per unit area these habitats lock away more carbon than land forests, mostly in their waterlogged soils.

✓ (a) The term refers to carbon stored in marine and coastal ecosystems; the colour 'blue' signals water.
✗ (b) Carbon held in forests and farm soils on land is usually called 'green carbon', not blue carbon.
✗ (c) Carbon in petroleum and natural gas is fossil carbon; burning it releases carbon dioxide rather than storing it.

Remember · Blue carbon = carbon stored by oceans and coastal ecosystems (mangroves, salt marshes, seagrasses); green carbon = land vegetation and soils.

Sources

IUCN Issues Brief: Blue carbon ↗ “Blue carbon is the carbon stored in coastal and marine ecosystems. Coastal ecosystems such as mangroves, tidal marshes and seagrass meadows sequester and store more carbon per unit area than terrestrial forests”
NOAA National Ocean Service: What is Blue Carbon? ↗ “Blue carbon is the term for carbon captured by the world's ocean and coastal ecosystems.”

Question and answer: UPSC's official GS Paper I (2021, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2021 · Q24

Medium

With reference to the 'New York Declaration on Forests', which of the following statements are correct?

1.It was first endorsed at the United Nations Climate Summit in 2014.
2.It endorses a global timeline to end the loss of forests.
3.It is a legally binding international declaration.
4.It is endorsed by governments, big companies and indigenous communities.
5.India was one of the signatories at its inception.

Select the correct answer using the code given below.

Answer & explanation

Answer: (a) 1, 2 and 4

The New York Declaration on Forests was launched at the UN Secretary-General's Climate Summit in New York on 23 September 2014. It is a voluntary political pledge, not a treaty, signed by a mixed coalition of governments, companies, NGOs and indigenous peoples' groups, with the shared goal of ending natural forest loss by 2030. India is not among its endorsers.

✓ 1. It was endorsed on 23 September 2014 at the Climate Summit convened in New York by UN Secretary-General Ban Ki-moon.
✓ 2. Its headline goals are to halve natural forest loss by 2020 and end it by 2030, alongside restoring 350 million hectares of degraded land.
✗ 3. It is a voluntary political declaration; it creates no legal obligations.
✓ 4. The launch coalition included 32 national governments, 18 sub-national governments, 40 companies, 16 indigenous peoples' groups and 49 NGOs and civil-society bodies.
✗ 5. India does not appear on the list of national government endorsers, either in 2014 or later.

Remember · NYDF (2014, UN Climate Summit, New York): voluntary, multi-stakeholder; end natural forest loss by 2030, restore 350 million ha. India has not endorsed it.

Sources

Forest Carbon Partnership Facility (World Bank), UNSG 2014 Climate Summit ↗ · reference work “On September 23, 2014 , at the Climate Summit in New York, a coalition of over 150, including 32 national governments, 18 sub-national governments, 40 companies, 16 Indigenous Peoples groups, and 49 NGOs/CSOs, endorsed the New York Declaration on Forests with the shared goal of ending natural forest loss by 2030.”
Forest Declaration Assessment, What is the New York Declaration on Forests? ↗ · reference work “The New York Declaration on Forests (NYDF) is a voluntary, multi-stakeholder political declaration calling for global action to protect, restore, and sustainably manage the world’s forests.”
Forest Declaration Assessment, NYDF Endorsers (national governments list) ↗ · reference work “Guyana 2014 Indonesia 2014 Japan 2014 Kenya 2014 Republic of Korea 2014”

Question and answer: UPSC's official GS Paper I (2021, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

Prelims 2021 · Q29

Medium

The 'Common Carbon Metric', supported by UNEP, has been developed for

Answer & explanation

Answer: (a) assessing the carbon footprint of building operations around the world

The Common Carbon Metric (2009) is a UNEP-backed method for measuring energy use and reporting greenhouse gas emissions from the operation of buildings, so that the carbon footprint of buildings anywhere can be assessed and compared on the same basis. It has nothing to do with farm carbon trading or national inventories.

✓ (a) Its full title is the 'Common carbon metric for measuring energy use and reporting greenhouse gas emissions from building operations', published by UNEP in 2009 through its Sustainable Buildings and Climate Initiative.
✗ (c) National emissions are reported through greenhouse gas inventories under the UNFCCC, not through this building-level metric.
✗ (d) The metric measures individual buildings' operational emissions, not global fossil-fuel emissions per unit time.

Remember · UNEP's Common Carbon Metric (2009) = a universal way to measure the operational carbon footprint of buildings (energy use and emissions per square metre or per occupant).

Sources

UNEP Knowledge Repository, Common carbon metric for measuring energy use and reporting greenhouse gas emissions from building operations (2009) ↗ “Supported by the United Nations Environment Programme, this new 'Common Carbon Metric' will allow emissions from buildings around the world to be consistently assessed and compared, and improvements measured.”

Question and answer: UPSC's official GS Paper I (2021, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ·

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