UPSC Prelims 2025 Environment questions: topic-wise weightage
UPSC Prelims 2025 asked 13 environment questions in GS Paper I, spread over 3 topics. See the environment weightage for 2025 below, then attempt each question with the official answer and an explanation.
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Environment 2025: questions by topic
- Biodiversity and species1
- Climate change and international conventions7
- Pollution, environmental laws and green technology5
Counted from the 13 questions on this page, tagged by topic in the Battle IAS PYQ bank.
Seeing 13 Environment questions spread over 3 topics can feel overwhelming. That's exactly why the Battle IAS PYQ Book maps every question topic by topic, so you know what to study first. Download free sample
Biodiversity and species 1
Regarding Peacock tarantula (Gooty tarantula), consider the following statements :
- I. It is an omnivorous crustacean.
- II. Its natural habitat in India is only limited to some forest areas.
- III. In its natural habitat, it is an arboreal species.
Which of the statements given above is/are correct?
Answer (d) & explanation
Statements II and III are correct (d). Statement II is right: the peacock tarantula (Gooty tarantula) is found only in a few forest patches of the Eastern Ghats, mainly in Andhra Pradesh. Statement III is right: it lives in tree holes, so it is arboreal. Statement I is wrong: it is a spider, an arachnid, not a crustacean, and it eats insects, not plants. So options (a), (b) and (c) fail.
Notice its status: it is Critically Endangered on the IUCN Red List, mainly due to deforestation and the pet trade, valued for its bright blue colour. It is named after Gooty town, where it was first found. Its bite is painful but rarely dangerous.
"crustacean" sounds scientific. Spiders are arachnids; crabs and prawns are crustaceans.
Answer as per the official UPSC answer key.
Climate change and international conventions 7
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 (c) & explanation
Only Statement III is correct and it explains Statement I (c). Statement I is right: India stayed out of the COP28 (Dubai, 2023) Declaration on Climate and Health. Statement III is right and is the reason: India worried that cutting emissions from health care now could limit the growth of its still-expanding health system and its resilience. Statement II is wrong: the declaration is voluntary, not binding; signing it would not make decarbonisation mandatory. So options (a), (b) and (d) fail.
Notice the bigger picture: COP28 also launched the Global Stocktake call to "transition away" from fossil fuels and set up the Loss and Damage Fund. India stresses equity and common but differentiated responsibilities.
"binding" is the error. COP declarations are political pledges, not treaties.
Answer as per the official UPSC answer key.
Consider the following statements :
- Statement I : Scientific studies suggest that a shift is taking place in the Earth’s rotation and axis.
- Statement II : Solar flares and associated coronal mass ejections bombarded the Earth’s outermost atmosphere with tremendous amount of energy.
- Statement III : As the Earth’s polar ice melts, the water tends to move towards the equator.
Which one of the following is correct in respect of the above statements?
Answer (b) & explanation
Both II and III are correct, but only III explains I (b). Statement I is right: studies show a shift in Earth's rotation and axis. Statement III is right and is the reason: melting polar ice moves mass towards the equator. Like a spinning skater stretching her arms, the Earth slows a little and its axis drifts. Statement II is right: solar flares and coronal mass ejections did hit the upper atmosphere hard, as in May 2024, but they do not move the planet's mass, so they do not explain I.
Notice another human factor: heavy pumping of groundwater has also shifted the axis, studies found. Solar storms instead cause auroras and can disrupt satellites, GPS and power grids.
Answer as per the official UPSC answer key.
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 (a) & explanation
Both II and III are correct and both explain Statement I (a). Article 6 of the Paris Agreement lets countries work together to meet their targets. Statement II is right: Articles 6.2 and 6.4 set up carbon markets, for trading credits between countries and through a UN-run mechanism. Statement III is right: Article 6.8 covers non-market approaches, such as joint finance, technology and capacity building. Both halves are why it is discussed so much, so options (b), (c) and (d) fail.
Notice the progress: rules for Article 6 carbon markets were finally agreed at COP29 in Baku (2024). India's own Carbon Credit Trading Scheme (2023) builds a domestic market, and India has signed Article 6.2 deals, such as with Japan.
Answer as per the official UPSC answer key.
Which one of the following launched the ‘Nature Solutions Finance Hub for Asia and the Pacific’?
Answer (a) & explanation
The Asian Development Bank launched the hub (a). The Asian Development Bank (ADB) launched the Nature Solutions Finance Hub for Asia and the Pacific in 2024. It aims to draw private money, at least $2 billion, into projects that protect or restore nature, such as mangroves, forests and watersheds. Option (b) is wrong: the AIIB, based in Beijing, did not launch it. Option (c) is wrong: the New Development Bank is the BRICS bank in Shanghai. Option (d) is wrong: the IBRD is the main lending arm of the World Bank.
Notice that the ADB is based in Manila, set up in 1966, with Japan and the USA as top shareholders. India is a founder member and among its largest borrowers.
Answer as per the official UPSC answer key.
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 (c) & explanation
Statements II and III are correct (c). Statement II is right: India is second in the Asia-Pacific region in CO₂ emissions from fuel burning, after China, and third in the world. Statement III is right: electricity and heat producers, mainly coal-based power plants, are the largest single source. Statement I is wrong: India emits about 2 tonnes of CO₂ per person, far below the world average of about 4.7 tonnes, but well above 0.5 tonnes. So options (a), (b) and (d) fail.
Notice India's targets: net zero by 2070, 50% of power capacity from non-fossil sources by 2030, a goal already reached in 2025, and cutting emissions intensity of GDP by 45% from 2005 levels.
India's per-capita figure is "low" compared with others, but not as low as 0.5 t.
Answer as per the official UPSC answer key.
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 (c) & explanation
Both statements are counted correct (c). Statement II is right: wet-bulb temperature combines heat and humidity. At about 35°C, sweat no longer evaporates, so the body cannot cool itself, threatening the survival of humans and animals. Statement I is counted too in UPSC's key: the warming that drives such heat also brings heavier floods, stronger cyclones and longer droughts to peninsular India. So options (a), (b) and (d) fail.
Notice where the risk is high: humid coastal and plains areas, like the Indo-Gangetic plains and the Odisha coast. The World Bank report was on investment in cooling. India's Heat Action Plans, first made in Ahmedabad in 2013, aim to cut heat deaths.
Answer as per the official UPSC answer key.
Which organization has enacted the Nature Restoration Law (NRL) to tackle climate change and biodiversity loss?
Answer (a) & explanation
The European Union enacted the Nature Restoration Law (a). The European Union adopted its Nature Restoration Law in 2024. It requires member states to restore at least 20% of the EU's damaged land and sea areas by 2030, and all ecosystems in need by 2050. Options (b), (c) and (d) are wrong: only a body that makes laws can "enact" one. The World Bank, OECD and FAO give loans, advice or technical help, but cannot pass binding laws.
Notice the link to the Kunming-Montreal Global Biodiversity Framework (2022), whose "30 by 30" target asks for 30% of land and sea to be protected by 2030. The EU law faced strong protests from farmers before it passed narrowly.
Answer as per the official UPSC answer key.
Pollution, environmental laws and green technology 5
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 (b) & explanation
Both II and III are correct, but only III explains I (b). Statement I is right: cement gives about 7–8% of the world's CO₂. Statement II is right: silica-bearing clay is mixed with limestone to make cement, but that step releases no carbon. Statement III is right and is the reason: heating limestone (CaCO₃) in a kiln gives lime (CaO) and CO₂. This calcination step, plus the fuel burnt for the high heat, causes most of the emissions. So options (a), (c) and (d) fail.
Notice the fixes: blending in fly ash or slag, LC3 (limestone calcined clay cement), and carbon capture. India is the world's second-largest cement producer after China, and its carbon market covers cement.
Answer as per the official UPSC answer key.
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 (c) & explanation
All three statements are correct (c). Direct Air Capture (DAC) pulls CO₂ straight from the open air using chemical filters or liquids. Statement I is right: the gas can be stored underground, a way of carbon sequestration. Statement II is right: it can be used as a raw material for plastics, and in food processing and fizzy drinks. Statement III is right: joined with green hydrogen, it can make synthetic low-carbon aviation fuel. So options (a), (b) and (d) fail.
Notice the difference from carbon capture and storage (CCS) at a factory chimney, where CO₂ is far more concentrated. DAC is still very expensive and energy-hungry. The world's largest plant, Mammoth, runs in Iceland.
Answer as per the official UPSC answer key.
Consider the following :
- I. Cigarette butts
- II. Eyeglass lenses
- III. Car tyres
How many of them contain plastic?
Answer (c) & explanation
All three contain plastic (c). Item I is right: cigarette filters are made of cellulose acetate, a plastic, and are among the most common litter on beaches. Item II is right: most spectacle lenses are polycarbonate or other plastics, not glass. Item III is right: tyres contain synthetic rubber and polymer fibres, and tyre wear is a big source of microplastics in air and water. So options (a), (b) and (d) fail.
Notice that microplastics, pieces under 5 mm, are now found in human blood, lungs and even the placenta. India banned many single-use plastic items from July 2022. Talks on a global plastics treaty have not yet reached agreement.
Answer as per the official UPSC answer key.
Consider the following statements :
- Statement I : Activated carbon is a good and an attractive tool to remove pollutants from effluent streams and to remediate contaminants from various industries.
- Statement II : Activated carbon exhibits a large surface area and a strong potential for adsorbing heavy metals.
- Statement III : Activated carbon can be easily synthesized from environmental wastes with high carbon content.
Which one of the following is correct in respect of the above statements?
Answer (a) & explanation
Both II and III are correct and both explain Statement I (a). Statement II is right: activated carbon is full of tiny pores, so one gram has a huge surface area, often over 1,000 m², on which pollutants and heavy metals stick (adsorption). That makes it work well. Statement III is right: it can be made cheaply from coconut shells, rice husk and other carbon-rich waste, which makes it attractive. Both explain Statement I, so options (b), (c) and (d) fail.
Notice the spelling: adsorption means sticking to a surface; absorption means soaking in. Activated carbon is used in water filters, gas masks, and treating poisoning in hospitals. India's coconut-growing south is a big producer.
Answer as per the official UPSC answer key.
Artificial way of causing rainfall to reduce air pollution makes use of
Answer (a) & explanation
Silver iodide and potassium iodide are used (a). Cloud seeding sprays particles into suitable clouds so that water droplets or ice crystals form around them. Silver iodide is the standard agent, as its crystal shape is close to ice, and potassium iodide is used with it. Rain then washes dust and smoke out of the air. Options (b), (c) and (d) are wrong: silver nitrate, potassium nitrate and potassium chloride are not the usual agents, though common salt is used in some warm-cloud seeding.
Notice the catch: seeding needs clouds with enough moisture; it cannot make rain from a clear sky. Delhi tried cloud seeding against smog with IIT Kanpur in 2025, with little success because the air was too dry.
Answer as per the official UPSC answer key.
All years by topic
Every question from 2011 to 2026, grouped by syllabus topic, with year-wise trends.