UPSC 2025 Environment and Ecology Questions with Answers
14 previous year UPSC Prelims questions on Environment and Ecology in the UPSC 2025 Prelims. Choose an option to see the answer and explanation.
Explanations state facts as of the year each question was asked; words like “recently” refer to that year.
Showing 11–14 of 14 questions
Browse Environment and Ecology chapters
UPSC 2025Environment and Ecology · Miscellaneous
Q11. 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?
Explanation
Statement I is correct: The circular economy model aims to reduce resource extraction, encourage recycling and reuse, and design out waste. All these reduce energy consumption and emissions. Greenhouse gas (GHG) emissions are reduced in several ways:
Lower extraction and processing of virgin materials (which is carbon-intensive). Emphasis on reuse, recycling, and resource efficiency. Waste reduction leads to less landfill methane and less incineration. Impact organisation Circle Economy’s Circularity Gap Report 2021 finds that circular economy strategies can cut global greenhouse gas emissions by 39%.
Statement II is correct: By emphasizing reuse, refurbishment, remanufacturing, and recycling, the circular economy significantly reduces the need for raw materials as inputs in production processes, conserving natural resources.
Statement III is correct: The circular economy focuses on reducing wastage in production by improving process efficiency, redesigning products for durability and easy repair, and adopting sustainable manufacturing practices. Statements II and III explain Statement I: Reducing raw material use (Statement II) and cutting production wastage (Statement III) both contribute to lower energy consumption and fewer emissions, which leads to a reduction in overall greenhouse gas emissions (Statement I).
Exam tip:
You can try, The "NOT" approach for all statements, this tests the improbability of negating a statement--if denying its impact seems highly unlikely, the statement is plausibly true. For example: Circular economy do NOT reduces the use of raw materials as inputs." Denial would contradict the very essence of the circular economy. So denial is implausible, meaning S2 is true. Similarly apply this approach in all three statements and you can observe all are true and logically correct explanation of S1.
UPSC 2025Environment and Ecology · Pollution
Q12. Artificial way of causing rainfall to reduce air pollution makes use of
Explanation
Cloud-seeding is a technique used to modify weather by releasing silver iodide (AgI) into the atmosphere to facilitate the formation of ice crystals, enhancing the cloud’s ability to generate rain. In the process of cloud-seeding, chemicals like silver iodide, potassium iodide, and dry ice are dispersed into the sky via airplanes and helicopters.
Additional insight:
Cloud seeding is divided into two main types:
Hygroscopic Cloud Seeding: This approach promotes the growth of water droplets in liquid clouds by introducing salt particles, typically at the cloud’s base, which helps the droplets combine and become heavy enough to fall as rain. Glaciogenic Cloud Seeding: This method encourages the formation of ice crystals in supercooled clouds by releasing substances such as silver iodide or dry ice, which serve as ice nuclei, initiating ice formation and ultimately leading to precipitation.
UPSC 2025Environment and Ecology · Environmental Laws, Conventions and Policies
Q13. Which organization has enacted the Nature Restoration Law (NRL) to tackle climate change and biodiversity loss?
Explanation
The European Union has introduced the Nature Restoration Law (NRL) to address climate change and the loss of biodiversity. This law requires member countries to meet specific targets for restoring damaged ecosystems on both land and sea, forming a central part of the EU’s environmental strategy. Its goal is to rejuvenate nature throughout Europe, benefiting wildlife, the climate, and communities. If properly enforced, the law could have a transformative impact. It is now essential for both the European Parliament and EU member nations to approve and promptly implement the legislation.
Exam tip:
The word "enacted" implies legislative authority -- only bodies with law-making power can do this. Only the EU has the jurisdiction and institutional setup to actually enact a law like the Nature Restoration Law (NRL).
UPSC 2025Environment and Ecology · Climate Change
Q14. 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.
Explanation
Wet-bulb temperature is the lowest temperature that air can reach through the process of evaporation of water under current atmospheric conditions. It is measured by wrapping a thermometer bulb in a wet cloth and exposing it to air flow; as water evaporates from the cloth, it cools the thermometer, and the resulting temperature is the wet-bulb temperature.
Statement 1 is incorrect: Flooding, tropical cyclones and droughts in the Peninsular India are significant impacts of climate change. These are not the direct implications of the wet-bulb temperatures exceeding 35°C. The World Bank’s warning in its report titled Climate Investment Opportunities in India’s Cooling Sector, specifically relates to heat and humidity, not to hydrometeorological events like floods or cyclones.
Statement 2 is correct: This statement directly reflects the core implication of the World Bank’s report titled "Climate Investment Opportunities in India’s Cooling Sector". At wet-bulb temperatures above 35°C, humans and animals cannot cool themselves through sweating, leading to life-threatening conditions.
Additional insight:
Wet-bulb temperature reflects both heat and humidity in the air. When relative humidity is high, less evaporation occurs, so the wet-bulb temperature is closer to the actual air temperature. When humidity is low, more evaporation happens, making the wet-bulb temperature much lower than the air temperature. At 100% relative humidity, the wet-bulb and air temperatures are equal because no more evaporation can occur. Wet-bulb temperature is important because it indicates the limit at which humans and animals can cool themselves by sweating. If the wet-bulb temperature rises above 35°C, the body can no longer shed heat effectively, making survival difficult even for healthy individuals.
Answer key for these questions
Q
UPSC year
Correct answer
11
2025
(a) Both Statement II and Statement III are correct and both of them explain Statement I
12
2025
(a) silver iodide and potassium iodide
13
2025
(a) The European Union
14
2025
(b) II only
Frequently asked questions
How many previous year UPSC questions are there on Environment and Ecology?
This page covers 14 previous year UPSC Prelims GS Paper-I questions on Environment and Ecology in the UPSC 2025 Prelims, asked from 1996 to 2025. Each has the correct answer and an explanation.
How should I use previous year UPSC questions for Prelims?
Attempt each question first, then open the answer and read the explanation for every option. Repeat by chapter, and track which statements UPSC reuses across years. Previous year questions show the exam pattern and difficulty level.
Which years are covered for Environment and Ecology?
Questions on Environment and Ecology in the UPSC 2025 Prelims are available for 22 years, from 1996 to 2025. Use the Year filter to practise a single paper.
