Climate change and international conventions: previous-year questions
49 real UPSC Prelims questions (2011–2026) with the official answer and a clear explanation. 17 of them came in the last five papers.
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Questions per year, counted from the official papers.
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Which one of the following statements best describes the term ‘Social Cost of Carbon’ ?
It is a measure, in monetary value, of the
Answer (a) & explanation
It measures the long-term damage from one tonne of CO₂ (a). The social cost of carbon puts a money value on the harm caused by emitting one more tonne of CO₂ in a given year: lost crops, health damage, floods, heat and lower productivity, added up over time. Governments use it to weigh the costs and benefits of climate policies and regulations. Option (b) describes a country's fossil fuel demand, not damage. Option (c) describes the burden on a climate refugee. Option (d) describes an individual's carbon footprint.
Notice the related ideas of carbon pricing: a carbon tax and emissions trading. India launched its Carbon Credit Trading Scheme in 2023 under the Energy Conservation Act.
Answer as per the official UPSC answer key.
In the context of which of the following do some scientists suggest the use of cirrus cloud thinning technique and the injection of sulphate aerosol into stratosphere?
Answer (d) & explanation
Both techniques aim to reduce global warming (d). They are geoengineering, or solar radiation management, ideas. Sulphate aerosols sprayed into the stratosphere would reflect sunlight back to space, copying big volcanic eruptions such as Mount Pinatubo (1991), which cooled the Earth by about 0.5°C. Cirrus cloud thinning would let more heat escape to space, because thin, high cirrus clouds trap outgoing heat. They are not for artificial rain (a), which uses cloud seeding with silver iodide; nor for cyclones (b); nor for solar wind (c).
Notice the risks: changed monsoons, ozone damage, and termination shock if it stops suddenly. Delhi tried cloud seeding against smog in 2025.
Answer as per the official UPSC answer key.
Which of the following statements are correct about the deposits of ‘methane hydrate’?
- 1. Global warming might trigger the release of methane gas from these deposits.
- 2. Large deposits of ‘methane hydrate’ are found in Arctic Tundra and under the seafloor.
- 3. Methane in atmosphere oxidizes to carbon dioxide after a decade or two.
Which of the statements given above are correct?
Answer (d) & explanation
All three statements are correct (d). Methane hydrate, or "fire ice", is methane trapped in ice-like crystals. It is stable only under cold and high pressure. Statement 2 is right because big deposits lie in Arctic permafrost and in seafloor sediments along continental margins. Statement 1 is right because warming could melt them and release methane, a strong greenhouse gas. This could set off a feedback loop, the "clathrate gun" idea. Statement 3 is right because methane in air lasts about a decade before it oxidises into CO₂ and water.
Methane is over 80 times stronger than CO₂ over 20 years. Notice India's interest: the National Gas Hydrate Programme found deposits in the Krishna–Godavari basin.
Answer as per the official UPSC answer key.
Which of the following statements best describes “carbon fertilization” ?
Answer (a) & explanation
Option (a) describes carbon fertilization. Plants use CO₂ for photosynthesis. When there is more CO₂ in the air, many plants, especially C3 plants such as wheat and rice, photosynthesise faster and grow more, and their stomata lose less water. This is the carbon fertilization effect, and satellites show a greening of the Earth partly because of it. Option (b) is the greenhouse effect or global warming. Option (c) is ocean acidification. Option (d) is not a scientific term.
Notice the limits: the benefit fades when nitrogen or water is short, and studies show crops grown under high CO₂ have less protein, zinc and iron. So more CO₂ is not good news for nutrition. C4 plants such as maize gain much less.
Answer as per the official UPSC answer key.
The Partnership for Action on Green Economy (PAGE), a UN mechanism to assist countries transition towards greener and more inclusive economies, emerged at
Answer (b) & explanation
PAGE emerged from Rio+20 (b). At the UN Conference on Sustainable Development (Rio+20) in Rio de Janeiro, 2012, the outcome document "The Future We Want" backed the green economy as a tool for sustainable development and poverty eradication. In response, PAGE was launched in 2013 to help countries shape green economy policies. Five UN agencies run it together: UNEP, ILO, UNDP, UNIDO and UNITAR. Johannesburg 2002 (a) was the World Summit on Sustainable Development. Paris 2015 (c) produced the Paris Agreement. The New Delhi summit (d) is TERI's annual event.
Rio+20 also started the process that produced the SDGs (2015). Notice the follow-up: India is not a PAGE partner country, but the idea links to its LiFE mission.
Answer as per the official UPSC answer key.
“Momentum for Change : Climate Neutral Now” is an initiative launched by
Answer (c) & explanation
The UNFCCC Secretariat launched it (c). Momentum for Change is a UNFCCC programme, started in 2011, that honours practical climate solutions, such as women-led projects and climate finance ideas. Climate Neutral Now, launched in 2015, invites people, companies and governments to measure their emissions, cut them, and offset the rest using UN-certified credits. The IPCC (a) assesses climate science and does not run such schemes. UNEP (b) runs other programmes, and the WMO (d) deals with weather and climate data.
Notice the related Article 6 carbon markets of the Paris Agreement, whose rules were finalised at COP29 (Baku, 2024). India launched its own Carbon Credit Trading Scheme (2023).
Answer as per the official UPSC answer key.
With reference to ‘Global Climate Change Alliance’, which of the following statements is/are correct?
- 1. It is an initiative of the European Union.
- 2. It provides technical and financial support to targeted developing countries to integrate climate change into their development policies and budgets.
- 3. It is coordinated by World Resources Institute (WRI) and World Business Council for Sustainable Development (WBCSD).
Select the correct answer using the code given below :
Answer (a) & explanation
Statements 1 and 2 are correct (a). The Global Climate Change Alliance was started by the European Union in 2007 (1) and became GCCA+ in 2014. It gives technical and financial support to poor, climate-exposed countries, mainly small island states (SIDS) and least developed countries (LDCs). The aim is to help them build climate change into their development policies and budgets (2), with a focus on adaptation and disaster risk reduction. Statement 3 is wrong because WRI and WBCSD run the GHG Protocol, not the GCCA.
Notice the trap: UPSC mixes up who runs which climate body. Remember these pairs: GCCA belongs to the EU, the CCAC to UNEP with partner countries, REDD+ to the UN or World Bank, and the GHG Protocol to WRI and WBCSD.
The WRI–WBCSD pairing belongs to the GHG Protocol.
Answer as per the official UPSC answer key.
Consider the following statements :
- 1. Climate and Clean Air Coalition (CCAC) to Reduce Short Lived Climate Pollutants is a unique initiative of G20 group of countries.
- 2. The CCAC focuses on methane, black carbon and hydrofluorocarbons.
Which of the statements given above is/are correct ?
Answer (b) & explanation
Only statement 2 is correct (b). Statement 1 is wrong because the Climate and Clean Air Coalition (CCAC) was started in 2012 by UNEP and six countries: Bangladesh, Canada, Ghana, Mexico, Sweden and the USA. It is not a G20 body. Statement 2 is right because it targets short-lived climate pollutants: methane, black carbon, HFCs and tropospheric ozone. These stay in the air only days to years, so cutting them slows warming quickly and also cleans the air.
India joined the CCAC in 2019. Notice the related efforts: the Global Methane Pledge (COP26, 30% cut by 2030), which India has not signed, and the Kigali Amendment (2016) to phase down HFCs, which India ratified in 2021.
Answer as per the official UPSC answer key.
In the context of mitigating the impending global warming due to anthropogenic emissions of carbon dioxide, which of the following can be the potential sites for carbon sequestration ?
- 1. Abandoned and uneconomic coal seams
- 2. Depleted oil and gas reservoirs
- 3. Subterranean deep saline formations
Select the correct answer using the code given below :
Answer (d) & explanation
All three are possible storage sites (d). Geological carbon sequestration, part of CCS (carbon capture and storage), pumps CO₂ deep underground. Unmineable coal seams absorb CO₂ onto the coal and can release methane in exchange, a method called ECBM (1). Depleted oil and gas fields once held gas safely for millions of years, and injecting CO₂ can also push out leftover oil (enhanced oil recovery) (2). Deep saline aquifers have the largest storage capacity of all (3).
Norway's Sleipner project has stored CO₂ in a saline formation since 1996. Notice India's steps: NITI Aayog's CCUS report (2022) and ONGC's EOR trials. Remember the other carbon sinks too: oceans, forests and soils.
Answer as per the official UPSC answer key.
The term ‘Intended Nationally Determined Contributions’ is sometimes seen in the news in the context of
Answer (b) & explanation
Intended Nationally Determined Contributions were climate pledges countries set for themselves before the Paris Agreement (2015), so the term relates to combating climate change (b). Once a country ratified the Agreement, its INDC became its NDC. The term has nothing to do with refugee pledges (a), AIIB capital (c) or the SDGs (d).
India pledged to cut emissions intensity of GDP by 33–35% from 2005 levels by 2030, and raised this to 45% in 2022, along with 50% of power capacity from non-fossil sources by 2030 and net zero by 2070. Notice how Paris replaced top-down targets with nationally decided ones.
Answer as per the official UPSC answer key.
What is/are the importance/importances of the ‘United Nations Convention to Combat Desertification’?
- 1. It aims to promote effective action through innovative national programmes and supportive international partnerships.
- 2. It has a special/particular focus on South Asia and North Africa regions, and its Secretariat facilitates the allocation of major portion of financial resources to these regions.
- 3. It is committed to bottom-up approach, encouraging the participation of local people in combating the desertification.
Select the correct answer using the code given below.
Answer (c) & explanation
Statements 1 and 3 are correct (c). The UNCCD (1994) promotes action through national action programmes and supportive international partnerships (1). It is committed to a bottom-up, community-led approach involving local people (3). Statement 2 is wrong: its special regional focus is Africa, not South Asia and North Africa, and the Secretariat does not allocate most funds to particular regions.
India hosted COP14 in Greater Noida in 2019 and aims to restore 26 million hectares of degraded land by 2030. Notice how desertification links to food security, migration and climate change.
South Asia never had special focus. Africa is the region the treaty highlights.
Answer as per the official UPSC answer key.
Consider the following pairs :
| Terms sometimes seen in the news | Their origin
| 1. Annex-I Countries | Cartagena Protocol
| 2. Certified Emissions Reductions | Nagoya Protocol
| 3. Clean Development Mechanism | Kyoto Protocol
Which of the pairs given above is/are correctly matched?
Answer (c) & explanation
Only pair 3 is correct (c). The Clean Development Mechanism comes from the Kyoto Protocol (1997). Pair 1 is wrong: Annex-I countries, the industrialised nations, are listed under the UNFCCC (1992), not the Cartagena Protocol. Pair 2 is wrong: Certified Emission Reductions are carbon credits earned under Kyoto's CDM, not the Nagoya Protocol.
Cartagena (2000) deals with the safe movement of living modified organisms, and Nagoya (2010) with access to genetic resources and benefit-sharing; both come under the CBD. Notice how the Paris Agreement's Article 6 carbon market now takes the place of the CDM, so these old terms still matter.
Cartagena and Nagoya are both CBD protocols, so neither belongs with climate terms.
Answer as per the official UPSC answer key.
Which of the following best describes/describe the aim of ‘Green India Mission’ of the Government of India?
- 1. Incorporating environmental benefits and costs into the Union and State Budgets thereby implementing the ‘green accounting’
- 2. Launching the second green revolution to enhance agricultural output so as to ensure food security to one and all in the future
- 3. Restoring and enhancing forest cover and responding to climate change by a combination of adaptation and mitigation measures
Select the correct answer using the code given below.
Answer (c) & explanation
Only statement 3 is correct (c). The Green India Mission, one of the eight missions under the National Action Plan on Climate Change (2008), aims to protect, restore and enhance forest cover and respond to climate change through both adaptation and mitigation. Statement 1 is wrong: green accounting in budgets is not its aim. Statement 2 is wrong: a second green revolution in farm output is an agriculture goal, not this mission's.
The mission seeks to improve forest and tree cover on millions of hectares and boost ecosystem services. Notice how it links to India's NDC promise of an extra carbon sink of 2.5–3 billion tonnes of CO₂ equivalent.
Answer as per the official UPSC answer key.
Which of the following statements is/are correct?
Proper design and effective implementation of UN-REDD+ Programme can significantly contribute to
- 1. protection of biodiversity
- 2. resilience of forest ecosystems
- 3. poverty reduction
Select the correct answer using the code given below.
Answer (d) & explanation
All three are correct (d). REDD+ (Reducing Emissions from Deforestation and forest Degradation, plus conservation, sustainable management and enhancing carbon stocks) pays developing countries for keeping forests standing. UN-REDD, started in 2008, is run jointly by the FAO, UNDP and UNEP. If it is well designed, it brings co-benefits: standing forests protect biodiversity (1), healthy and connected forests are more resilient to climate stress (2), and payments that reach forest communities help reduce poverty (3).
The word "proper design" in the question is the clue. Badly designed REDD+ can push out tribal people. That is why safeguards on indigenous rights matter, and in India they link with the Forest Rights Act, 2006.
Answer as per the official UPSC answer key.
What is ‘Greenhouse Gas Protocol’?
Answer (a) & explanation
The GHG Protocol is an accounting tool (a). It was built by the World Resources Institute (WRI) and the World Business Council for Sustainable Development (WBCSD). It is the most widely used standard for measuring and managing emissions. It sorts emissions into Scope 1 (direct), Scope 2 (purchased electricity) and Scope 3 (the value chain). It is not a UN financial incentive (b); that describes REDD+ or climate funds. It is not a treaty with a 2022 target (c), and it is not a World Bank REDD+ initiative (d), such as the Forest Carbon Partnership Facility.
Notice how this matters today. SEBI's BRSR reporting for listed companies and India's Carbon Credit Trading Scheme both rely on this kind of emissions accounting.
Answer as per the official UPSC answer key.
With reference to ‘Agenda 21’, sometimes seen in the news, consider the following statements :
- 1. It is a global action plan for sustainable development.
- 2. It originated in the World Summit on Sustainable Development held in Johannesburg in 2002.
Which of the statements given above is/are correct?
Answer (a) & explanation
Only statement 1 is correct (a). Agenda 21 is a non-binding, global action plan for sustainable development in the 21st century. Statement 2 is wrong because it was adopted at the Rio Earth Summit (UNCED), 1992, not at Johannesburg. The World Summit on Sustainable Development, Johannesburg 2002 (Rio+10) only reviewed how it was being carried out. Rio also produced the UNFCCC, the CBD, the Rio Declaration and the Forest Principles.
Its local version, Local Agenda 21, asked city governments to make their own plans. Notice the order of events: Stockholm 1972, Rio 1992, Johannesburg 2002, Rio+20 2012 ("The Future We Want"), and then the SDGs/Agenda 2030 in 2015, which carry Agenda 21's ideas forward.
Johannesburg was the review summit. Rio 1992 is where Agenda 21 began.
Answer as per the official UPSC answer key.
With reference to the Agreement at the UNFCCC Meeting in Paris in 2015, which of the following statements is/are correct?
- 1. The Agreement was signed by all the member countries of the UN and it will go into effect in 2017.
- 2. The Agreement aims to limit the greenhouse gas emissions so that the rise in average global temperature by the end of this century does not exceed 2°C or even 1.5°C above pre-industrial levels.
- 3. Developed countries acknowledged their historical responsibility in global warming and committed to donate $ 1000 billion a year from 2020 to help developing countries to cope with climate change.
Select the correct answer using the code given below.
Answer (b) & explanation
Only statement 2 is correct (b). The Paris Agreement (COP21, 2015) aims to keep the rise in global temperature well below 2°C above pre-industrial levels and to try to limit it to 1.5°C (2). Statement 1 is wrong because it came into force on 4 November 2016, after the 55-country, 55%-of-emissions threshold was crossed. Not every UN member had signed it. Statement 3 is wrong because the finance goal was $100 billion a year, not $1,000 billion, and it was a collective goal, not an admission of historical blame.
At COP29 (Baku, 2024) a new goal (NCQG) of $300 billion a year by 2035 was set. Notice that countries set their own targets (NDCs). India's include net zero by 2070 and 50% non-fossil power capacity, which it reached in 2025.
Watch the zero: the goal was 100 billion dollars, not 1000.
Answer as per the official UPSC answer key.
Consider the following statements :
- 1. The Sustainable Development Goals were first proposed in 1972 by a global think tank called the ‘Club of Rome’.
- 2. The Sustainable Development Goals have to be achieved by 2030.
Which of the statements given above is/are correct?
Answer (b) & explanation
Only statement 2 is correct (b). The SDGs were proposed at Rio+20 (2012), with Colombia and Guatemala pushing the idea. The UN adopted them in September 2015 as Agenda 2030: 17 goals and 169 targets to be met by 2030 (2). They replaced the eight MDGs (2000–2015). Statement 1 is wrong because the Club of Rome's 1972 report The Limits to Growth warned about resource limits but never proposed the SDGs.
In India, NITI Aayog tracks progress through its SDG India Index, and Kerala and Uttarakhand usually rank at the top. Notice the related term sustainable development, made popular by the Brundtland Report, Our Common Future (1987): meeting today's needs without harming future generations.
Answer as per the official UPSC answer key.
With reference to ‘Forest Carbon Partnership Facility’, which of the following statements is/are correct?
- 1. It is a global partnership of governments, businesses, civil society and indigenous peoples.
- 2. It provides financial aid to universities, individual scientists and institutions involved in scientific forestry research to develop eco-friendly and climate adaptation technologies for sustainable forest management.
- 3. It assists the countries in their ‘REDD+ (Reducing Emissions from Deforestation and Forest Degradation+)’ efforts by providing them with financial and technical assistance.
Select the correct answer using the code given below.
Answer (c) & explanation
Statements 1 and 3 are correct (c). The Forest Carbon Partnership Facility (World Bank, 2008) brings together governments, businesses, civil society and indigenous peoples (1). Its Readiness Fund and Carbon Fund help countries prepare for REDD+ and pay them for verified emission cuts (3). Statement 2 is wrong: it does not give research grants to universities or individual scientists.
REDD+ pays developing countries to keep forests standing, also rewarding conservation and sustainable management. Notice how forests are treated as climate assets, linking this to the BioCarbon Fund in the previous question.
Answer as per the official UPSC answer key.
What is Rio+20 Conference, often mentioned in the news?
Answer (a) & explanation
Rio+20 was the UN Conference on Sustainable Development, held in Rio de Janeiro in 2012, twenty years after the 1992 Earth Summit (a). It was not a WTO ministerial (b), an IPCC meeting (c) or a CBD Conference of Parties (d).
Its outcome document, "The Future We Want", started the process that led to the Sustainable Development Goals, adopted in 2015 with 17 goals and a 2030 deadline. It also highlighted the green economy. The 1992 summit had produced the UNFCCC, the CBD and Agenda 21. Notice how this chain of summits shapes today's development agenda.
Answer as per the official UPSC answer key.