The UPSC Prelims 2025 question paper continued its legacy of being unpredictable, analytical, and concept-driven. With 100 questions in General Studies Paper I, the trend clearly reflected a balanced distribution across subjects like Polity, Economy, Environment, Science & Tech, History, and Geography. Among them, Environment & Ecology stood out with a total of 13 questions, constituting a significant portion and demanding focused preparation.
Overall Nature of UPSC Prelims 2025
This year, the paper appeared moderately tougher compared to the previous year. Questions across all subjects ranged from easy to medium and difficult levels, indicating a layered testing approach. The hallmark of this year's paper was its emphasis on core fundamentals, often intertwined with current affairs, reinforcing the need for integrated preparation.
Given below is the breakdown of the 100 questions asked in CSE Prelims 2025.
Environment & Ecology Section: Key Observations
The Environment & Ecology section in UPSC Prelims 2025 reflected a noticeable shift in focus. Rather than concentrating on static topics like species and ecological behavior, the paper leaned towards contemporary environmental issues and technological solutions. The questions tested both core concepts and awareness of current global challenges, particularly those linked to climate change and innovation.
Notable Themes Covered:
- Climate Change Mitigation Technologies – e.g., Direct Air Capture
- Artificial Weather Modification – e.g., Artificial Rainfall
- Sustainable Development and Climate Finance Mechanisms-e.g. Article 6 Paris Climate deal
The Detailed Analysis of UPSC Prelims 2025 Environment Section are as follows:
UPSC Prelims Environment & Ecology Q.
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?
(a) Both Statements II and III are correct and both of them explain Statement I
(b) Both Statement II and Statement III are correct but only one of them explains Statement I
(c) Only one of the Statement II and III is correct and that explains Statement I
(d) Neither Statement II nor Statement III is correct
Answer: B
Explanation
- Recently, researchers used more than 120 years of data to decipher how melting ice, dwindling groundwater, and rising seas are nudging the planet’s spin axis and lengthening days. Days on Earth are growing slightly longer, and that change is accelerating. The reason is connected to the same mechanisms that also have caused the planet’s axis to meander by about 30 feet (10 meters) in the past 120 years. The findings come from two recent NASA-funded studies focused on how the climate-related redistribution of ice and water has affected Earth’s rotation.
- In recent decades, the faster melting of ice sheets has shifted mass from the poles toward the equatorial ocean. This redistribution occurs when ice sheets and glaciers melt more than they grow from snowfall and when aquifers lose more groundwater than precipitation replenishes. These resulting shifts in mass cause the planet to wobble as it spins and its axis to shift location — a phenomenon called polar motion. They also cause Earth’s rotation to slow, measured by the lengthening of the day. Both have been recorded since 1900. This flattening causes Earth to decelerate and the day to lengthen, similar to when an ice skater lowers and spreads their arms to slow a spin.
- Although solar flares, and associated coronal mass ejections, can bombard Earth’s outermost atmosphere with tremendous amounts of energy, most of that energy is reflected back into space by the Earth’s magnetic field. While the energy doesn't decisively affect earth's rotation and axis, it causes heating and expansion of the thermosphere, disrupts radio communications, and affects satellites and power grids. Auroras, or the northern and southern lights, are also a direct result of these interactions. Hence, Both Statement II and Statement III are correct but only one of them explains Statement I.
MOTIVATION, SOURCES AND COVERAGE OF PRELIMS QUESTION IN THE VISIONIAS SOURCES
Motivation: Recently, it was reported that the Earth's rotation speed was slowing down due to glacial melt.
Sources:
Coverage of the topic in the VisionIAS Current Affairs Sources
- PT 365 2025 Environment: 6.5.4. NEGATIVE LEAP SECOND
- Monthly Current Affairs May 2024: Article 7.2. Solar Storm (Geomagnetic Storm)
- News today (30 April 2024): According to a study, climate change has slowed Earth’s rotation and could affect timekeeping
UPSC Prelims Environment & Ecology Q.
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?
(a) Both Statement II and Statement III are correct and both of them explain Statement I
(b) Both Statement II and Statement III are correct but only one of them explains Statement I
(c) Only one of the Statements II and III is correct and that explains Statement I
(d) Neither Statement II nor Statement III is correct
Answer: A
Explanation
- Article 6 of the Paris Agreement enables international cooperation to tackle climate change and to unlock financial support for developing countries.
- There are three components to Article 6:
- Article 6.2: Provides accounting and reporting guidance for Parties to use internationally transferred mitigation outcomes towards their nationally determined contributions (NDCs).
- Article 6.4: Establishes a new UNFCCC mechanism which can be used to trade high-quality carbon credits.
- Article 6.8: Provides opportunities for non-marketbased cooperation for enhancing climate action.
- In essence, Article 6 aims to facilitate international collaboration and enhance climate ambition by enabling countries to work together to reduce emissions and achieve their climate goals. It's a crucial part of the Paris Agreement, allowing for flexibility and cooperation in implementing the treaty's commitments. Hence, Both Statement II and Statement III are correct and both of them explain Statement I.
MOTIVATION, SOURCES AND COVERAGE OF PRELIMS QUESTION IN THE VISIONIAS SOURCES
Motivation: Recently, the United Nations Climate Change Conference or Conference of the Parties (COP) of the UNFCCC, COP29 was held which marked the adoption of Article 6 of the Paris Agreement after nine years of negotiations.
Sources:
- https://unfccc.int/process/the-paris-agreement/cooperative-implementation#:~:text=Article%206%20of%20the%20Paris%20Agreement%20enables%20international%20cooperation%20to,cooperation%20for%20enhancing%20climate%20action.
Coverage of the topic in the VisionIAS Current Affairs Sources
- PT 365 2025 Environment: Article 2.2.4. Article 6
- Monthly Current Affairs November 2024: Article 5.2. Carbon Trading and Market
Coverage of Topic in the VisionIAS All India Test Series/ Sandhan/Open Test
2025 All India Test Series Test 4719:
Q. Recently, the United Nations Climate Change Conference or Conference of the Parties (COP) of the UNFCCC, COP29 was held which marked the adoption of Article 6 of the Paris Agreement after nine years of negotiations. The conference was held at
(a) Geneva, Switzerland
(b) Baku, Azerbaijan
(c) Dubai, United Arab Emirates
(d) Sharm El Sheikh, Egypt
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.
(a) I and II only
(b) III only
(c) I, II and III
(d) None of the above statements is correct
UPSC Prelims Environment & Ecology Q.
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.
(a) I and II only
(b) III only
(c) I, II and III
(d) None of the above statements is correct
Answer: C
Explanation
- Direct air capture (DAC) technologies extract CO2 directly from the atmosphere at any location, unlike carbon capture which is generally carried out at the point of emissions, such as a steel plant. The CO2 can be permanently stored in deep geological formations or used for a variety of applications. This is carbon sequestration. Hence, statement I is correct.
- The captured CO2 can be used as a feedstock for various carbon-based materials. It can be used in the production of cement, plastics, carbon fibers, and other industrial applications. This helps keep carbon stored in the infrastructure, preventing its release into the atmosphere for extended periods. DAC-captured CO2 can be used for applications like carbonation in beverages and as a food preservative. Hence, statement II is correct.
- Direct air capture (DAC) can be a source of carbon for combining with hydrogen to create synthetic lowcarbon fuels, a technology that is increasingly being explored for decarbonizing aviation. This process, also known as Power-to-Liquid (PtL) or e-fuel production, uses renewable electricity to split water into hydrogen and oxygen, then combines the hydrogen with CO2 captured from the atmosphere via DAC to produce synthesis gas, which is further processed into synthetic jet fuel. Hence, statement III is correct.
MOTIVATION, SOURCES AND COVERAGE OF PRELIMS QUESTION IN THE VISIONIAS SOURCES
Motivation: Direct Air Capture is frequently seen in the news.
Sources:
Coverage of the topic in the VisionIAS Current Affairs Sources
- PT 365 2025 Environment: Article 2.3.3. Direct Air Capture and Storage (DAC+S) Plant
- Monthly Current Affairs May 2024: Article 5.9.5. Direct Air Capture and Storage (DAC+S) plant
- News Today (15 May 2025): India Unveils First Cluster of Five Carbon Capture and Utilisation (CCU) Testbeds for Cement Sector.
Coverage of Topic in the VisionIAS All India Test Series/ Sandhan/Open Test
2025 All India Test Series Test 4719:
Q. Which of the following processes is/are associated with the function of carbon sinks?
1. Direct air capture (DAC)
2. Ocean Iron fertilization
3. Soil carbon sequestration
4. Ocean Alkalinity Enhancement
Select the correct answer using code given below.
(a) 1 and 4 only
(b) 2 and 3 only
(c) 1, 2 and 3 only
(d) 1, 2, 3 and 4
The remaining Environment & Ecology questions from UPSC Prelims 2025 are discussed in - Part 3 of the series.
VisionIAS Faculty Discussion: Environment & Ecology Section Analysis of UPSC Prelims 2025
To help aspirants decode the evolving pattern and approach of UPSC Prelims 2025, our expert faculty at VisionIAS has conducted a detailed analysis session, focusing on the trends, difficulty level, question framing, and effective strategies for future preparation. This video not only breaks down the Environment & Ecology questions but also offers valuable insights on elimination techniques, source mapping, and topic prioritization for UPSC Prelims 2026.
To watch the CSE Prelims 2025 Analysis Video, click on the following link:
UPSC Prelims 2025 | GS Paper 1 | Analysis & Discussion I Geography - Environment
Prepare Smarter with VisionIAS: 10-Year PYQ Environment & Ecology Compilation
To help aspirants systematically decode trends, VisionIAS has released a comprehensive compilation of last 10 years’ Environment & Ecology PYQs (2015–2024). This document offers:
- Topic-wise categorization
- Difficulty level analysis
- Source identification
- Elimination strategies
- Micro-level sub-topic mapping
- Current affairs integration guide
Link to read and download the document: 10 year UPSC PYQ Trend Analysis : Environment
Our faculty at VisionIAS has conducted an insightful discussion on the Environment & Ecology PYQ Trend Analysis Document. This session covers key patterns, conceptual depth of questions, and strategies to tackle future Prelims papers more effectively. The discussion also highlights how our 10-year PYQ document can be used as a powerful tool for focused preparation.
To watch the discussion by our faculty, click on the link below: GS Prelims | 10 Year PYQ (2015 - 2024) | Environment - Part 2
Further, understand the UPSC Prelims with VisionIAS's Master Classes on PYQ of UPSC Prelims. This program transforms 13 years of UPSC previous year question papers into a powerful strategy- building resource. Designed to enhance your accuracy, speed, and conceptual clarity, it's a smart way to turn UPSC PYQs into your strongest preparation tool