UPSC Prelims 2019 CSAT Paper II · Q65 of 79 Comprehension medium

Passage

Passage – 3 Temperatures have risen nearly five times as rapidly on the Western Antarctic Peninsula than the global average over the past five decades. Researchers have now found that melting glaciers are causing a loss of species diversity among benthos in the coastal waters off the Antarctic Peninsula, impacting an entire seafloor ecosystem. They believe increased levels of suspended sediment in water to be the cause of the dwindling biodiversity in the coastal region.

On the basis of the above passage, the following assumptions have been made : 1. Regions of glaciers warm faster than other regions due to global warming. 2. Global warming can lead to seafloor sedimentation in some areas. 3. Melting glaciers can reduce marine biodiversity in some areas. Which of the above assumptions is/are valid?

  1. (a) 1 and 2 only
  2. (b) 3 only
  3. (c) 2 and 3 only ✓ UPSC's answer
  4. (d) 1, 2 and 3

Why the answer is (c)

• Assumption 1 is invalid because the passage states that the Western Antarctic Peninsula warmed faster than the global average, but it does not generalize that all glacier regions warm faster than other regions.

• Assumption 2 is valid because the passage links melting glaciers to increased levels of suspended sediment in coastal waters, implying global warming (via melting) leads to sedimentation.

• Assumption 3 is valid because the passage explicitly states that melting glaciers are causing a loss of species diversity among benthos, which constitutes a reduction in marine biodiversity.

• Since assumptions 2 and 3 are supported by the text while assumption 1 is an overgeneralization, the correct combination is 2 and 3 only.

Why the other options are wrong

(a) 1 and 2 only
Option (a) is incorrect because it includes Assumption 1, which is not supported by the passage as it generalizes the warming rate of all glacier regions.
(b) 3 only
Option (b) is incorrect because it excludes Assumption 2, which is valid as the passage links melting glaciers to increased suspended sediment.
(d) 1, 2 and 3
Option (d) is incorrect because it includes Assumption 1, which is an invalid generalization not stated in the passage.

Asked in the CSAT Paper II of the UPSC Civil Services Preliminary Examination 2019, held on 2 June 2019. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.

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