Climate Change: UPSC Previous Year Questions (Environment and Ecology)
30 previous year UPSC Prelims questions on climate change appear here, from 2008 to 2025. The 2025 paper alone asked about cement emissions, COP28, Article 6, Direct Air Capture, per capita emissions and wet-bulb temperatures. UPSC also asks about carbon markets, geoengineering ideas and forest declarations. The explanations give the mechanism and the institution behind each.
Explanations state facts as of the year each question was asked; words like “recently” refer to that year.
Showing 21–30 of 30 questions
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UPSC 2011Environment and Ecology · Climate Change
Q21. Human activities in the recent past have caused the increased concentration of carbon dioxide in the atmosphere, but a lot of it does not remain in the lower atmosphere because of 1. Its escape into the outer stratosphere. 2. The photosynthesis by phytoplankton in the oceans: 3. The trapping of air in the polar ice caps. Which of the statements given above is/are correct?
Explanation
For slowing down global warming, carbon sequestration involves the capture and storage of CO₂. It is captured from the air, industries or power stations and stored permanently underground. This promotes Long-term reserve of CO₂ or forms of carbon to control temperatures. Carbon sequestration aids in lowering the amount of GHGs (due to combustion of fossil fuels) present in the air.
Statement 2 is correct: The photosynthesis by phytoplankton in the oceans is natural carbon sequestration and it is responsible for much of CO₂ being moved from lower atmosphere to oceans:
Statements 1 is incorrect: CO₂ is a heavy gas that primarily accumulates in the troposphere and lower stratosphere but does not escape into the outer stratosphere or space. The primary removal mechanisms of CO₂ involve absorption by oceans, photosynthesis by plants, and geological sequestration rather than atmospheric escape. Statements 3 is incorrect: Polar ice caps and glaciers are not a major active carbon sink. Ice trapping does not remove a significant amount of CO₂ from the atmosphere on short time scales. While some CO₂ gets sealed in glaciers but melting due to climate change can release CO₂ back into the atmosphere thereby making this process less effective in long-term carbon storage.
UPSC 2011Environment and Ecology · Climate Change
Q22. Consider the following: 1. Carbon dioxide 2. Oxides of Nitrogen 3. Oxides of Sulphur Which of the above is/are the emission/emissions from coal combustion at thermal power plants?
Explanation
Emissions of all the above-mentioned gases i.e. Carbon dioxide, Oxides of Nitrogen and Oxides of Sulphur take place from coal combustion at thermal power plants. Gas Sources Carbon dioxide (CO₂) Burning of fossil fuels, deforestation Oxides of Sulphur Burning fossil fuels, Smelting ores, Volcanic eruptions, Vehicles, etc Nitrogen oxides (N₂O) Burning of fossil fuels, fertilizers; burning of wood and crop residue. Carbon Monoxide (CO) Iron ore smelting, burning of fossil fuels, burning e-waste.
UPSC 2011Environment and Ecology · Climate Change
Q23. The formation of ozone hole in the Antarctic region has been a cause of concern. What could be the reason for the formation of this hole?
Explanation
Antarctic Ozone Hole was discovered by British Antarctic Survey scientists Farman, Gardiner and Shanklin in 1985. The formation of the ozone hole in the Antarctic has been an annual occurrence (in the months of September, October and November, due to a set of special meteorological and chemical conditions that arise at the South Pole, such as the presence of strong polar front, polar stratospheric clouds and increasing inflow of human-made chemicals like CFCs, etc.
UPSC 2011Environment and Ecology · Climate Change
Q24. Regarding "carbon credits", which one of the following statements is not correct?
Explanation
Carbon Credit is a permit that allows the company the right to emit 1 tonne of CO₂ or its equivalent. One credit permits the emission of a mass equal to one ton of carbon dioxide. Statement (a) is correct: The carbon credit system was established as part of the Kyoto Protocol (1997) to allow countries to meet their emission reduction targets via flexible mechanisms such as Carbon Trading, Clean Development Mechanism (CDM), etc. Statement (b) is correct: Under Kyoto mechanisms, countries or entities that emit less than their allowed quota can earn carbon credits, which they can then sell to others who are exceeding limits. Statement (c) is correct: The core objective is to create a market-based incentive to limit global greenhouse gas emissions, especially CO₂. Statement (d) is incorrect: Carbon credit prices are not fixed by UNEP (United Nations Environment Programme). They are determined by market forces in various carbon exchanges, such as the European Union Emission Trading Scheme (EU-ETS). UNEP does not set or fix prices.
UPSC 2010Environment and Ecology · Climate Change
Q25. What are the possible limitations of India in mitigating the global warming at present and in the immediate future? 1. Appropriate alternate technologies are not sufficiently available. 2. India cannot invest huge funds in research and development. 3. Many developed countries have already set up their polluting industries in India. Which of the statements given above is/are correct?
Explanation
Statements 1 is correct: India lacks sufficient alternative technologies, such as those for renewable energy and waste management, which are essential for mitigating global warming. This gap hampers the country’s ability to address climate change effectively. Statements 2 is correct: As a developing country, India faces challenges in investing significant funds into research and development due to its economic constraints.
Statement 3 is incorrect: It is not accurate to claim that developed countries have primarily set up polluting industries in India. Developed countries have shifted some industries to developing nations due to lower environmental regulations and labor costs (a process known as carbon leakage) but this is not a dominant factor in India’s overall emissions. India has strict environmental regulations such as Extended Producer Responsibility (EPR) and Corporate Social Responsibility (CSR) norms.
UPSC 2010Environment and Ecology · Climate Change
Q26. Consider the following which can be found in the ambient atmosphere: 1. Soot 2. Sulphur hexafluoride 3. Water vapour Which of the above contribute to the warming up of the atmosphere?
Explanation
The Earth’s atmosphere contains gases and particles that contribute to the greenhouse effect, trapping heat and leading to global warming. These gases absorb and re-emit infrared radiation, while particles like soot can alter solar radiation balance and reduce the reflectivity of surfaces like ice and snow, further influencing climate change.
Option (d) is correct:
Soot directly contributes to warming by absorbing sunlight and reducing the reflectivity of snow and ice. Sulphur hexafluoride is a potent greenhouse gas with a high global warming potential. Water vapour is the most significant greenhouse gas and amplifies the warming effect through feedback mechanisms. Other gases that contribute to the greenhouse effect and cause global warming are Carbon Dioxide, Methane, Nitrous Oxide, Ozone and Chlorofluorocarbons (CFCs).
UPSC 2010Environment and Ecology · Climate Change
Q27. The United Nations Framework Convention on Climate Change (UNFCCC) is an international treaty drawn at:
Explanation
The United Nations Framework Convention on Climate Change (UNFCCC) was drawn up at the UN Conference on Environment and Development, Rio de Janeiro, 1992. This conference, also known as the Earth Summit, set the foundation for global cooperation on climate change and sustainable devel-opment.
UPSC 2009Environment and Ecology · Climate Change
Q28. The concept of carbon credit originated from which one of the following?
Explanation
A carbon credit represents the reduction or removal of 1 metric ton of CO₂ or its equivalent from the atmosphere. It allows for compensating carbon emissions by funding projects that either reduce emissions, like renewable energy or energy efficiency, or remove CO₂ through methods like reforestation or carbon capture. The concept of carbon credits was formalized under the Kyoto Protocol (1997), introducing mechanisms like Emission Trading, where countries could sell excess credits, and the Clean Development Mechanism (CDM), allowing investments in emission-reduction projects in developing countries for credits.
UPSC 2009Environment and Ecology · Climate Change
Q29. In the context of CO₂ emission and Global Warming, what is the name of a market driven device under the UNFCCC that allows developing countries to get funds/ incentives from the developed countries to adopt better technologies that reduce greenhouse gas emissions?
Explanation
The Clean Development Mechanism (CDM) under the UNFCCC allows developing countries to receive funds from developed countries for adopting technologies that reduce green-house gas emissions, promoting sustainable development. The Clean Development Mechanism (CDM) allows developed countries to invest in emission-reduction projects in developing countries and earn carbon credits in return. Options (a), (b) and (d) are incorrect:
Carbon footprint refers to the total carbon dioxide (CO₂) emissions linked to the activities of an individual or entity (e.g., building, company, country). Emission Reduction Norms refer to regulations or standards set to limit the amount of greenhouse gases that can be emitted by industries, sectors, or countries. Carbon Credit Rating is a measure of how reliable and effective a carbon credit is in reducing emissions and helping the environment.
UPSC 2008Environment and Ecology · Climate Change
Q30. Consider the following statements: 1. Clean Development Mechanism (CDM) in respect of carbon credits is one of the Kyoto Protocol Mechanisms. 2. Under the CDM, the projects handled pertain only to the Annex-I countries. Which of the statements given above is/are correct?
Explanation
The Clean Development Mechanism (CDM) under the UNFCCC enables developing countries to receive funds from developed nations for adopting technologies that reduce green-house gas emissions. It allows developed countries to invest in emission-reduction projects in developing countries. In return, these developed countries earn carbon credits while promoting sustainable development.
Statement 1 is correct. CDM is indeed one of the Kyoto Protocol mechanisms designed to help reduce greenhouse gas emissions by allowing developed countries to invest in emission-re-duction projects in developing countries.
Statement 2 is incorrect. CDM projects are implemented in developing countries, not in Annex I countries (which are mostly developed nations). The idea is that developed countries (Annex I) can earn carbon credits by funding emission-reducing projects in developing countries (non-Annex I).
Answer key for these questions
Q
UPSC year
Correct answer
21
2011
(b) 2 only
22
2011
(d) 1, 2 and 3
23
2011
(b) Presence of prominent polar front and stratospheric clouds; and inflow of chlorofluorocarbons.
24
2011
(d) Carbon credits are traded at a price fixed from time to time of the United Nation Environment Programme
25
2010
(a) 1 and 2 only
26
2010
(d) 1, 2 and 3
27
2010
(b) UN ‘Conference on Environment and Development, Rio de Janeiro, 1992
28
2009
(b) Kyoto Protocol
29
2009
(c) Clean Development Mechanism
30
2008
(a) 1 only
What UPSC has tested in Climate Change
Article 6 of the Paris Agreement deals with carbon markets and cooperative approaches between countries.
Direct Air Capture extracts carbon dioxide directly from the atmosphere and can be used for carbon sequestration.
Cirrus cloud thinning is suggested by some scientists as a way of reducing the global warming.
Climate Action Tracker is a database created by climate research organisations that monitors countries’ emission pledges.
The World Bank has warned that India could become one of the first places where wet-bulb temperatures exceed human tolerance.
Frequently asked questions
How many previous year UPSC questions are there on Climate Change?
This page covers 30 previous year UPSC Prelims GS Paper-I questions on Climate Change (Environment and Ecology), asked from 2008 to 2025. Each has the correct answer and an explanation.
What does Article 6 of the Paris Agreement cover?
Voluntary cooperation between countries to meet their climate targets, including carbon markets in which emission reductions can be traded and used toward national contributions, along with non-market approaches.
What is Direct Air Capture?
A technology that removes carbon dioxide directly from the ambient air using chemical solvents or solid sorbents. The captured carbon can be stored underground or used in fuels and products, so it can help cut atmospheric carbon.
What is a wet-bulb temperature?
A measure that combines heat and humidity. When the wet-bulb temperature approaches 35 °C, the human body can no longer cool itself by sweating, so even healthy people can die within hours without relief.
