Q11. What is the primary cause of the current global sea-level rise directly linked to global warming?
Environmental Issues: Desertification, Deforestation, Climate Change and Ozone Depletion: RAS Prelims MCQs
75 RAS Prelims MCQs on environmental issues cover desertification, deforestation, global warming, climate agreements and the ozone layer. Greenhouse gases, the IPCC, the Montreal Protocol, the Kigali Amendment, the Paris Agreement, the Great Green Wall and desertification in Rajasthan and India are asked as facts, dates and statements.
Practice questions based on the RPSC RAS Prelims syllabus. They follow the exam pattern but are not past-paper questions.
Showing 11–20 of 75 questions
Q12. Given below are two statements, one labelled as
Assertion (A) and the other as Reason (R):
Assertion (A): The ozone hole is most prominently observed over Antarctica during its spring season.
Reason (R): Polar stratospheric clouds form during the extremely cold winter, providing surfaces for chemical reactions that release ozone-depleting reactive chlorine.
Select the correct answer from the codes given below:
Assertion (A) and the other as Reason (R):
Assertion (A): The ozone hole is most prominently observed over Antarctica during its spring season.
Reason (R): Polar stratospheric clouds form during the extremely cold winter, providing surfaces for chemical reactions that release ozone-depleting reactive chlorine.
Select the correct answer from the codes given below:
Explanation
Extremely low temperatures during the Antarctic winter lead to the formation of polar stratospheric clouds. These clouds facilitate unique chemical reactions that release reactive chlorine from reservoir species. When sunlight returns in the spring, this chlorine rapidly destroys ozone molecules, creating the seasonal ozone hole. This localized phenomenon demonstrates the interaction between atmospheric physics and man-made chemicals.
Q13. Which of the following best describes the core objective of the Great Green Wall initiative?
Explanation
The Great Green Wall is an ambitious African-led initiative aiming to restore 100 million hectares of degraded land. It focuses on the Sahel region to combat desertification, improve food security, and create jobs. Rather than just planting a line of trees, it promotes a mosaic of sustainable land management practices and agroforestry tailored to local ecological needs.
Q14. Which of the following pairs concerning the consequences of deforestation is correctly matched?
Explanation
Forests act as major carbon reservoirs, storing vast amounts of carbon in their biomass and soil. When trees are cut and burned or left to decay, this stored carbon is released back into the atmosphere as carbon dioxide. This process significantly contributes to the greenhouse effect, making deforestation a major driver of global warming and climate change.
Q15. Consider the following statements regarding the Paris Agreement:
I. It aims to hold the increase in the global average temperature to well below 2.0 degrees Celsius above pre-industrial levels.
II. It requires all signatory countries to pursue efforts to limit the temperature increase to 1.5 degrees Celsius.
III. It enforces top-down, legally binding emission reduction targets imposed by the UN on all member states.
IV. It relies on Nationally Determined Contributions (NDCs) submitted by individual countries.
Which of the above statement(s) is/are correct?
I. It aims to hold the increase in the global average temperature to well below 2.0 degrees Celsius above pre-industrial levels.
II. It requires all signatory countries to pursue efforts to limit the temperature increase to 1.5 degrees Celsius.
III. It enforces top-down, legally binding emission reduction targets imposed by the UN on all member states.
IV. It relies on Nationally Determined Contributions (NDCs) submitted by individual countries.
Which of the above statement(s) is/are correct?
Explanation
The Paris Agreement focuses on limiting global temperature increases to well below 2.0 degrees Celsius. It encourages efforts to reach a 1.5-degree limit to minimize severe impacts. Countries submit Nationally Determined Contributions, which are self-defined climate action plans. Unlike earlier treaties, it uses a flexible bottom-up approach rather than imposing top-down, legally binding emission targets on states.
Q16. Globally, which region is currently experiencing the highest absolute rate of tropical deforestation?
Explanation
Although forest loss occurs globally, the Amazon Basin currently experiences the highest absolute rates of tropical deforestation. Driven by agricultural expansion and cattle ranching, this loss threatens the world’s most biodiverse ecosystem. Protecting the Amazon is vital for maintaining regional rainfall patterns and global carbon cycles. Monitoring these trends is essential for international conservation efforts and climate mitigation.
Q17. Consider the following statements regarding the causes of desertification:
Statement I: Improper irrigation practices in arid and semi-arid regions can lead to waterlogging and severe soil salinization.
Statement II: The accumulation of salts in the topsoil makes it unviable for agriculture, thereby accelerating the process of desertification.
Which of the above statement(s) is/are correct?
Statement I: Improper irrigation practices in arid and semi-arid regions can lead to waterlogging and severe soil salinization.
Statement II: The accumulation of salts in the topsoil makes it unviable for agriculture, thereby accelerating the process of desertification.
Which of the above statement(s) is/are correct?
Explanation
Improper irrigation in drylands often leads to waterlogging and the subsequent accumulation of salts in the topsoil. This process, known as salinization, makes the land toxic for most crops and vegetation.
Q18. How does the melting of Arctic ice contribute to a positive feedback loop in global climate change?
Explanation
The melting of Arctic sea ice reduces the Earth’s albedo, which is the reflectivity of the surface. White ice reflects sunlight, but dark open water absorbs more solar energy, leading to further warming. This additional heat causes more ice to melt, creating a self-reinforcing positive feedback loop. This mechanism significantly accelerates the rate of warming in polar regions.
Q19. Which of the following is NOT considered a greenhouse gas?
Explanation
Greenhouse gases are characterized by their ability to absorb and emit infrared radiation, trapping heat in the atmosphere. Common examples include carbon dioxide, methane, and nitrous oxide. Nitrogen, which makes up about 78% of the atmosphere, does not have this property due to its simple diatomic structure. Therefore, it does not contribute directly to the greenhouse effect or global warming.
Q20. Match List-I with List-II:
Select the correct answer from the codes given below:
| International Protocol/Agreement | Primary Focus Area |
|---|---|
| A. Montreal Protocol | i. Bottom-up approach for climate action via NDCs |
| B. Kyoto Protocol | ii. Phasing out of Ozone Depleting Substances |
| C. Paris Agreement | iii. Combating land degradation and desertification |
| D. UNCCD | iv. Legally binding emission targets for developed nations |
Explanation
The Montreal Protocol addresses ozone depletion, while the Kyoto Protocol established binding targets for developed nations. The Paris Agreement introduced a bottom-up approach through self-determined contributions. The United Nations Convention to Combat Desertification focuses on land degradation. Understanding these different frameworks is essential for recognizing how the international community addresses diverse environmental challenges through specialized legal and cooperative mechanisms.Answer key for these questions
| Q | Correct answer |
|---|---|
| 11 | (d) Thermal expansion of seawater combined with the melting of land-based glaciers and ice. |
| 12 | (a) Both A and R are true and R is the correct explanation of A. |
| 13 | (c) To restore degraded landscapes and combat desertification across the Sahel via sustainable management. |
| 14 | (d) Carbon release - Decaying or burning cleared vegetation releases stored atmospheric CO 2 . |
| 15 | (a) I, II and IV |
| 16 | (b) The Amazon Basin in South America |
| 17 | (a) Both Statement I and Statement II are correct. |
| 18 | (a) Exposed dark ocean water has a lower albedo, absorbing more radiation and accelerating warming. |
| 19 | (c) Nitrogen (N2) |
| 20 | (a) A-ii, B-iv, C-i, D-iii |
Key facts from Environmental Issues: Desertification, Deforestation, Climate Change and Ozone Depletion
- Water vapour is the most abundant greenhouse gas, and the ozone layer lies in the stratosphere.
- The IPCC was established in 1988; the order is Montreal Protocol, IPCC, UNFCCC, Paris Agreement.
- The Kigali Amendment of 2016 targets the phase-down of hydrofluorocarbons (HFCs).
- The Amazon Basin has the highest absolute rate of tropical deforestation and holds about half the world’s remaining tropical rainforest.
- The Great Green Wall is an African initiative; about 30 per cent of India’s area is undergoing land degradation or desertification.
- In the Thar desert, wind erosion and shifting sand dunes are the most widespread problem; poor drainage in irrigated dry land causes salinisation.
Frequently asked questions
How many RAS Prelims practice MCQs are there on Environmental Issues: Desertification, Deforestation, Climate Change and Ozone Depletion?
This page has 75 practice MCQs on Environmental Issues: Desertification, Deforestation, Climate Change and Ozone Depletion (World Geography). Each has the correct answer, and most have an explanation.
When was the IPCC established?
In 1988, by the World Meteorological Organization and the United Nations Environment Programme. It assesses the science of climate change and its reports guide the climate negotiations, including the Paris Agreement.
What does the Kigali Amendment target?
The phase-down of hydrofluorocarbons (HFCs), which are strong greenhouse gases used in cooling. It was adopted in 2016 as an amendment to the Montreal Protocol, which was originally made to protect the ozone layer.
What is the Great Green Wall?
An African initiative to restore land and plant a belt of trees across the Sahel, south of the Sahara. Its aim is to fight desertification, improve food security and support local communities.