Q41. In which year did the United Nations Convention to Combat Desertification (UNCCD) formally enter into force?
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 41–50 of 75 questions
Q42. Arrange the following greenhouse gases in ascending order based on their Global Warming Potential (GWP) over a 100-year period relative to CO 2 :
I. Methane (CH 4 )
II. Carbon dioxide (CO 2 )
III. Nitrous oxide (N 2 O)
IV. Chlorofluorocarbon-12 (CFC-12)
Select the correct sequence:
I. Methane (CH 4 )
II. Carbon dioxide (CO 2 )
III. Nitrous oxide (N 2 O)
IV. Chlorofluorocarbon-12 (CFC-12)
Select the correct sequence:
Explanation
Global Warming Potential measures how much heat a gas traps relative to carbon dioxide, which has a value of one. Methane has a higher potential than CO 2 , followed by nitrous oxide. Synthetic chemicals like CFC-12 have the highest potentials, often thousands of times greater than CO 2 . This ranking highlights why even small emissions of certain industrial gases can have significant climate impacts.
Q43. Which of the following statements regarding the global significance of Amazon deforestation is correct?
Explanation
The Amazon rainforest is a global biodiversity hotspot, home to a vast array of unique plant and animal species. Deforestation directly threatens this richness through habitat destruction and fragmentation. Beyond local impacts, the loss of this forest disrupts regional rainfall and reduces the global carbon sink. Protecting the Amazon is therefore critical for both biological conservation and stabilizing the Earth’s climate system.
Q44. Consider the following statements regarding the consequences of deforestation:
I. It disrupts the local hydrological cycle, often leading to reduced precipitation in the area.
II. It increases the albedo of the cleared land, affecting local energy balances.
III. It results in an immediate increase in the amount of organic carbon securely stored in the soil.
Which of the above statement(s) is/are correct?
I. It disrupts the local hydrological cycle, often leading to reduced precipitation in the area.
II. It increases the albedo of the cleared land, affecting local energy balances.
III. It results in an immediate increase in the amount of organic carbon securely stored in the soil.
Which of the above statement(s) is/are correct?
Explanation
Deforestation significantly alters local environments by reducing evapotranspiration, which can lead to lower rainfall. It also typically increases surface albedo, as cleared land reflects more sunlight than dark forest canopies. Contrary to increasing soil carbon, the removal of vegetation and subsequent soil disturbance usually leads to a rapid loss of organic carbon. This happens as the soil organic matter decomposes more quickly.
Q45. What is the chemical formula of stratospheric ozone, and how is it naturally formed?
Explanation
Stratospheric ozone has the chemical formula O 3 . It forms naturally through a process where high-energy ultraviolet radiation splits diatomic oxygen molecules into individual atoms. These highly reactive oxygen atoms then collide and bond with other oxygen molecules to create triatomic ozone. This continuous cycle of creation and destruction maintains a steady-state concentration of ozone, which filters harmful UV radiation from reaching Earth.
Q46. Consider the following statements regarding climate change feedbacks:
Statement I: As global temperatures rise, permafrost in the Arctic regions begins to thaw.
Statement II: Thawing permafrost primarily absorbs methane from the atmosphere, creating a negative feedback loop that cools the planet.
Which of the above statement(s) is/are correct?
Statement I: As global temperatures rise, permafrost in the Arctic regions begins to thaw.
Statement II: Thawing permafrost primarily absorbs methane from the atmosphere, creating a negative feedback loop that cools the planet.
Which of the above statement(s) is/are correct?
Explanation
Rising global temperatures cause Arctic permafrost to thaw, which is an observed physical process. However, this thawing releases trapped greenhouse gases like methane and carbon dioxide into the atmosphere. Because these gases trap more heat, they accelerate further warming, creating a positive feedback loop rather than a cooling effect. This mechanism is a major concern for future climate stability and warming rates.
Q47. Consider the following statements based on the key findings of recent IPCC reports:
I. Human activities are unequivocally responsible for the observed warming of the atmosphere, ocean, and land.
II. Global surface temperature will continue to increase until at least mid-century under all assessed emission scenarios.
III. Limiting human-induced global warming requires achieving at least net zero CO 2 emissions.
IV. Climate change is already affecting many weather and climate extremes in every region across the globe.
V. Sea level rise is predicted to completely reverse and drop to pre-industrial levels by 2100.
Which of the above statement(s) is/are incorrect?
I. Human activities are unequivocally responsible for the observed warming of the atmosphere, ocean, and land.
II. Global surface temperature will continue to increase until at least mid-century under all assessed emission scenarios.
III. Limiting human-induced global warming requires achieving at least net zero CO 2 emissions.
IV. Climate change is already affecting many weather and climate extremes in every region across the globe.
V. Sea level rise is predicted to completely reverse and drop to pre-industrial levels by 2100.
Which of the above statement(s) is/are incorrect?
Explanation
Recent IPCC reports confirm that human activities are responsible for global warming and that temperatures will rise through mid-century. They also emphasize that reaching net zero CO 2 is necessary to stabilize the climate. However, sea-level rise is a long-term process that is projected to continue for centuries due to ongoing ocean warming and ice melt, rather than reversing by 2100.
Q48. Which of the following is NOT an effective strategy for combating desertification?
Explanation
Combating desertification requires sustainable land management practices like agroforestry, terracing, and rotational grazing. These methods help maintain soil structure, moisture, and fertility. In contrast, intensive monoculture without rest periods depletes soil nutrients and increases vulnerability to erosion. Such practices accelerate land degradation and desertification. Effective strategies instead focus on diversifying crops and allowing land to recover through natural or managed cycles.
Q49. Match List-I with List-II concerning global environmental treaties and their adoption years:
Select the correct answer from the codes given below:
| Treaty/Agreement | Adoption Year |
|---|---|
| A. UNFCCC | i. 1987 |
| B. UNCCD | ii. 1992 |
| C. Montreal Protocol | iii. 1994 |
| D. Paris Agreement | iv. 2015 |
Explanation
Global environmental governance has seen the adoption of several landmark treaties over the decades. The Montreal Protocol was established in 1987 to protect the ozone layer. The UNFCCC followed in 1992, providing a framework for climate action. The UNCCD was adopted in 1994 to address desertification. Most recently, the Paris Agreement was reached in 2015, setting new targets for global temperature limits.
Q50. Which of the following represents the most accurate description of how the Intergovernmental Panel on Climate Change (IPCC) develops its assessment reports?
Explanation
The Intergovernmental Panel on Climate Change does not carry out its own scientific research. Instead, hundreds of experts from around the world volunteer to review and synthesize existing peer-reviewed literature. This process ensures that its assessment reports reflect the current global scientific consensus on climate change. These summaries provide policymakers with the most reliable and comprehensive information available for decision-making.Answer key for these questions
| Q | Correct answer |
|---|---|
| 41 | (c) 1996 |
| 42 | (b) II, I, III, IV |
| 43 | (d) The Amazon holds about 10% of global biodiversity, which is severely threatened by habitat loss. |
| 44 | (a) I and II only |
| 45 | (d) O 3 ; formed when UV light splits O 2 molecules, which then combine with unbroken O 2 . |
| 46 | (c) Statement I is correct, but Statement II is incorrect. |
| 47 | (b) V only |
| 48 | (b) Promoting intensive monoculture farming without fallow periods |
| 49 | (a) A-ii, B-iii, C-i, D-iv |
| 50 | (c) It synthesizes published scientific papers to summarize climate drivers and potential impacts. |
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.