Prelims GS I · 245 questions · 2011–2026
Environment & ecology: every Prelims question, by topic
UPSC syllabus: “General issues on Environmental ecology, Bio-diversity and Climate Change - that do not require subject specialization.” Below, the topics inside it — most asked first — and how often each came up year by year.
Environment & ecology in Prelims 2022: 16 questions
All years →- Q21 · Climate change & agreementsAmong the following crops, which one is the most important anthropogenic source of both methane and nitrous oxide?…
- Q30 · Protected areas & conservationConsider the following pairs: Hokera Wetland — Punjab Renuka Wetland — Himachal Pradesh Rudrasagar Lake — Tripura Sasthamkotta Lake — Tamil Nadu…
- Q41 · Climate change & agreements"Climate Action Tracker" which monitors the emission reduction pledges of different countries is a:…
- Q42 · Climate change & agreementsConsider the following statements: "The Climate Group" is an international non-profit organization that drives climate action by building large networks and runs them. The International Energy Agency …
- Q43 · Ecology & ecosystems"If rainforests and tropical forests are the lungs of the Earth, then surely wetlands function as its kidneys." Which one of the following functions of wetlands best reflects the above statement?…
- Q44 · Pollution & wasteIn the context of WHO Air Quality Guidelines, consider the following statements: The 24-hour mean of PM2.5 should not exceed 15 µg/m3 and annual mean of PM2.5 should not exceed 5 µg/m3. In a year, the…
- Q45 · Biodiversity, plants & animalsWith reference to "Gucchi" sometimes mentioned in the news, consider the following statements: It is a fungus. It grows in some Himalayan forest areas. It is commercially cultivated in the Himalayan f…
- Q46 · Pollution & wasteWith reference to polyethylene terephthalate, the use of which is so widespread in our daily lives, consider the following statements: Its fibres can be blended with wool and cotton fibres to reinforc…
- Q47 · Biodiversity, plants & animalsWhich of the following is not a bird?…
- Q49 · Ecology & ecosystems"Biorock technology" is talked about in which one of the following situations?…
- Q50 · Ecology & ecosystemsThe "Miyawaki method" is well known for the:…
- Q75 · Environmental laws, bodies & conventionsWhich one of the following has been constituted under the Environment (Protection) Act, 1986?…
- Q80 · Climate change & agreementsWhich one of the following best describes the term “greenwashing”?…
- Q89 · Environmental laws, bodies & conventionsWith reference to Indian laws about wildlife protection, consider the following statements: Wild animals are the sole property of the government. When a wild animal is declared protected, such animal …
- Q90 · Biodiversity, plants & animalsCertain species of which one of the following organisms are well known as cultivators of fungi?…
- Q100 · Pollution & wasteConsider the following: Carbon monoxide Nitrogen oxide Ozone Sulphur dioxide…
Environment & ecology in UPSC Prelims at a glance
UPSC has asked 245 questions on Environment & ecology in GS Paper I from 2011 to 2026 — about 15 a year, the most in 2014 (23). The most-asked topic is Biodiversity, plants & animals (62 questions).
| Year | 2011 | 2012 | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 | 2026 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Questions | 16 | 18 | 17 | 23 | 15 | 17 | 13 | 11 | 18 | 12 | 20 | 16 | 13 | 14 | 13 | 9 |
Counted from UPSC's own papers in the Vault, each question under its main subject · updated 8 Nov 2026.
- Biodiversity, plants & animals62 questions · asked in 15 of 16 years
- Pollution & waste43 questions · asked in 15 of 16 years
- Climate change & agreements40 questions · asked in 14 of 16 years
- Environmental laws, bodies & conventions40 questions · asked in 15 of 16 years
- Ecology & ecosystems33 questions · asked in 11 of 16 years
- Protected areas & conservation27 questions · asked in 13 of 16 years
Latest questions
- 2026 · Q21 · Climate change & agreementsConsider 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…
- 2026 · Q22 · Biodiversity, plants & animalsWith respect to the Western Hoolock Gibbons, which of the following statements is/are correct?…
- 2026 · Q23 · Ecology & ecosystemsWhich of the following best explain(s) the rationale for protecting mangrove ecosystems in the context of climate resilience?…
- 2026 · Q27 · Biodiversity, plants & animalsWhich of the following statements with regard to the arrival of Amur Falcons at Doyang Lake in Nagaland each year from Mongolia is/are correct?…
- 2026 · Q32 · Protected areas & conservationWith reference to Madhav National Park, which of the following statements is/are correct?…
The same ground in Mains
These official Mains syllabus lines cover Environment & ecology. Prelims facts become Mains arguments.
Environment & ecology PYQs as a PDF — free
All 48 PDFs →Every Environment & ecology question from 2011 to 2026, topic-wise, with answers and explanations — 120 pages. Free; sign up once.
Environment & ecology PYQs: quick answers
How many Environment & ecology questions has UPSC asked in Prelims from 2011 to 2026?
245 questions in GS Paper I — about 15 a year, the most in 2014 (23). Every one is on this page, under its topic, with UPSC's answer and an explanation.
Which Environment & ecology topic does UPSC ask most in Prelims?
Biodiversity, plants & animals: 62 questions between 2011 and 2026, asked in 15 of 16 years. The topics are listed above, most asked first, each with its year-by-year trend.
Are the answers UPSC's official answer keys?
From 2016, yes: every answer is from UPSC's final answer key (2016–2025); for 2011–2015, where UPSC published no key online, each answer is worked out from official sources and reviewed independently; for 2026 UPSC has so far published a provisional key, and those answers are labelled. Explanations cite official sources — NCERT and government pages first.
Can I download the Environment & ecology PYQs as a PDF?
Yes — a print-ready PDF of every Environment & ecology question with answers and explanations (120 pages, 2.4 MB), free after a one-time sign-up, from the Vault's downloads page.
Counted from UPSC's own papers in the Vault; answers are UPSC's keys.
