259 previous year UPSC Prelims Environment and Ecology questions are on this page, from 1996 to 2025, in 10 chapters. Species, Pollution, Environmental Laws and Conventions and Climate Change are the largest, and recent papers lean on statement-pairs about news items: Direct Air Capture, the Nature Restoration Law, PFAS and the Peacock tarantula. Filter by chapter to revise one area, or by year for a single paper.
Explanations state facts as of the year each question was asked; words like “recently” refer to that year.
Showing 71–80 of 259 questions
The Common Carbon Metric’ is a protocol developed by United Nations Environment Program’s Sustainable Buildings & Climate Initiative (UNEP-SBCI) for measuring energy use & reporting GHG emissions from Building Operations. Its purpose is to support greenhouse gas (GHG) emission’s reductions through accurate measurement of energy efficiency improvements in building operations.
Blue Carbon is the carbon captured by the world’s ocean and coastal ecosystems. There are three types of coastal ecosystems -- mangroves, seagrasses and tidal marshes; these store half the "blue" carbon buried beneath the ocean floor. These areas absorb and store carbon at a much faster rate than other areas, such as forests, and can continue to do so for millions of years. The carbon found in coastal soil is often thousands of years old.
Statement 1 is correct: The NYDF was launched and endorsed at the United Nations Climate Summit in New York on September 23, 2014. It was a significant global effort to address deforestation and promote forest conservation.
Statement 2 is correct: The NYDF sets a global timeline to end natural forest loss by 2030 and to restore 350 million hectares of degraded forest and agricultural land by the same year. It also aims to halve deforestation by 2020 (though this target was not met).
Statement 3 is incorrect: The New York Declaration on Forests (NYDF) is a voluntary and non-legally binding international declaration aimed at ending global deforestation.
Statement 4 is correct: The NYDF has been endorsed by a wide range of stakeholders, including national governments, multinational companies, NGOs, and indigenous communities. Over 200 entities have pledged their support.
Statement 5 is incorrect: India was not a signatory to the NYDF at its inception. While many countries, including the United States, Canada, and several European nations, endorsed the declaration, India has still not joined as a signatory.
For S3, since when declarations become legally binding? Aren’t treaties there for that? Legally binding is strong requirement, seldom international declaration are legally binding, hence more likely false. Eliminating options B and C. Now as compare to S5(much more specific and hence easy to manipulate) S2 is much more general and practical to be false.
Option 1 is correct: Hedgehogs are small mammals with short limbs and a body low to the ground. Their most distinctive characteristic is the thousands of stiff, sharp spines -harder and sharper than those of a porcupine - that cover the animal’s back and sides, like a pincushion filled with needles. If attacked they will curl into a prickly and unappetizing ball that deters most predators.
Option 2 is incorrect: Marmot are any of 14 species of giant ground squirrels found primarily in North America and Eurasia. Marmots are well suited for life in cold environments and have small fur-covered ears, short, stocky legs, and strong claws for digging. Marmots do not roll up and protect their vulnerable parts. They often use their sharp teeth and powerful jaws to defend themselves.
Option 3 is correct: Pangolin, also called scaly anteaters be-cause of their preferred diet. They are the most trafficked mammal in the world. If touched or grabbed it will roll up completely into a ball, while the sharp scales on the tail can be used to lash out.
Option (c) is correct: Filter feeders are a subgroup of suspension feeding animals that feed by straining suspended matter and food particles from water, typically bypassing the water over a specialised filtering structure. Clams, krill, sponges, oysters, etc are among the creatures that rely on this way of feeding (including some sharks). Filter feeders include some birds like flamingos and several varieties of duck. Filter feeders are regarded as ecosystem engineers since they might be crucial in the clarification of water. They serve as indicator organisms and are crucial in bioaccumulation.
Option (a), (b) and (d) are incorrect:
Catfish are bottom-dwellers that feed on a variety of food sources, including insects, crustaceans, and small fish. Octopuses are predators that feed on crustaceans, mollusks, and fish. Pelicans are birds that feed on fish and other aquatic animals.
Statement 1 is incorrect: Oil palm trees are native to West Africa but were brought to South-East Asia over 100 years ago as an ornamental tree crop. Southeast Asia, particularly Indonesia and Malaysia, is the largest producer of palm oil.
Statement 2 is correct: Non-food applications of Palm oil are Cosmetics, toiletries, soaps and detergents. Oleochemical industry, as a base material for laundry detergents, household cleaners and cosmetics.
Statement 3 is correct: Palm oil can be used to produce biodiesel, which can be used in compression ignition engines, i.e., diesel engines without any modifications.
S2 and S3 mentions "Some" and "Can be used" which are not absolute requirement, it is possible hence likely true. Thus eliminate options A and C.
Leguminous plants have small pockets or nodules in their roots that host a specific type of bacteria known as nitrogen-fixing bacteria. Statements 1 and 2 are incorrect: Moringa is a rapidly growing, drought-tolerant tree native to the Indian subcontinent. It is found naturally in the sub-Himalayan regions of Northern India and is now cultivated globally in tropical and subtropical climates. Unlike leguminous plants, Moringa is not a legume and is deciduous, shedding its leaves seasonally. On the other hand, tamarind, a leguminous tree known for its edible fruit, is native to tropical Africa, not South Asia. Statements 3 and 4 are correct: In India most of the Tamarind is collected as Minor Forest Produce with Minimum Support Price. Tamarind is also actively exported from India.
Statement 5 is correct: Biodiesel is derived from the tamarind seed through the transesterification process as potential alternative feedstock for the diesel engine. Seeds of Moringa too can be used for biodiesel production.
The R2 Code of Practices (R2 Standard) is a set of guidelines designed to promote environmentally responsible practices in the electronics recycling industry. It provides a framework for recyclers to ensure that electronic waste (e-waste) is managed in a way that protects human health, safety, and the environment. The R2 Standard covers areas such as:
Safe handling and disposal of hazardous materials.
Data security and destruction.
Worker health and safety.
Environmental responsibility.
Fertigation is a technique for applying fertilizer where the drip irrigation system incorporates the fertilizer into the irrigation water. In this technology, irrigation is used to evenly disperse fertiliser solutions. Fertigation is practised extensively in commercial agriculture and horticulture. Fertigation is used to supplement nutrients that are already present or to make up for nutrient shortages found during plant tissue analysis.
Statement 1 is correct: Drip irrigation also avoids water spill-age on the field which could have promoted weed growth or increased soil alkalinity due to water logging.
Statement 2 is incorrect: Rock phosphate is not water-solu-ble and thus not suitable for fertigation. Only water-soluble fertilizers are effectively used in fertigation systems.
Statement 3 is correct: Accurate placement of nutrient, where the water goes the nutrient goes as well. Thus, increased nutrient absorption by plants.
Statement 4 is correct: Fertigation mixes fertilizers into irrigation water so that plants receive small, measured amounts of nutrients regularly, which minimizes the risk of nutrient losses through leaching.
We have to find one wrong statements among given 4 to reach correct option. Only S2, contains extreme phrase like "all other phosphatic fertilizer", even if one fertilizer doesn’t satisfy the condition, it make the statement false, hence S2 is more probable to be false.
The practice of sowing seed without tillage or preparation of soil is called Zero-tillage or No-till farming. In some cases it may reduce labour, fuel, irrigation and machinery costs. Another possible benefit is that because of the higher water content, instead of leaving a field fallow it can make economic sense to plant another crop instead. No-till farming decreases the amount of soil erosion tillage causes in certain soils, especially in sandy and dry soils on sloping terrain.
Statement 1 is correct: Zero tillage is the process where the crop seed will be sown through drillers without prior land preparation and disturbing the soil where previous crop stubbles are present.
Statement 2 is correct: Direct Seeded Rice (DSR) is a viable option to reduce the unproductive water flows, with increasing shortage of water, dry-DSR with minimum or zero tillage further enhances the benefits of this technology by saving labour.
Statement 3 is correct: Carbon sequestration is the process of capturing and storing atmospheric carbon dioxide to mitigate climate change. No-tillage farming has been claimed to increase soil organic matter, and thus increase carbon sequestration.
| Q | UPSC year | Correct answer |
|---|---|---|
| 71 | 2021 | (a) Assessing the carbon footprint of building operations around the world |
| 72 | 2021 | (a) Carbon captured by oceans and coastal ecosystems |
| 73 | 2021 | (a) 1, 2 and 4 |
| 74 | 2021 | (d) 1 and 3 |
| 75 | 2021 | (c) Oyster |
| 76 | 2021 | (b) 2 and 3 only |
| 77 | 2021 | (b) 3, 4 and 5 |
| 78 | 2021 | (a) environmentally responsible practices in electronics recycling industry |
| 79 | 2020 | (c) 1, 3 and 4 only |
| 80 | 2020 | (d) 1, 2 and 3 |
This page covers 259 previous year UPSC Prelims GS Paper-I questions on Environment and Ecology, asked from 1996 to 2025. Each has the correct answer and an explanation.
Species has the most with 43 questions, followed by Pollution and Environmental Laws, Conventions and Policies with 39 each, and Climate Change with 30. Environmental Organisations and Miscellaneous are the smallest.
Take a chapter at a time with the Chapter filter, attempt the questions and read the facts UPSC has tested. Revise Species and Protected Areas with a map and a list of national parks at hand.
Yes. The 2025 paper’s Environment questions on activated carbon, cement emissions, COP28, Article 6, Direct Air Capture, the Gooty tarantula, plastics and the Nature Restoration Law are included with full explanations.
