2014 GS Paper I, all questions

UPSC Prelims 2014 · GS Paper I

Question 53: Environment and Ecology

The scientific view is that the increase in global temperature should not exceed 2 °C above pre-industrial level. If the global temperature increases beyond 3 °C above the pre-industrial level, what can be its possible impact/impacts on the world?

  1. 1.Terrestrial biosphere tends toward a net carbon source.
  2. 2.Widespread coral mortality will occur.
  3. 3.All the global wetlands will permanently disappear.
  4. 4.Cultivation of cereals will not be possible anywhere in the world.

Select the correct answer using the code given below.

a1 only
b1 and 2 only
c2, 3 and 4 only
d1, 2, 3 and 4

AnswerUPSC’s answer is (b).

Climate assessments warn that beyond about 3 degrees of warming above the pre-industrial level, the land biosphere tends to turn from a net carbon sink to a net carbon source, which speeds up warming, and that widespread coral mortality occurs. Claims that all wetlands will permanently disappear or that cereals could not be grown anywhere are exaggerations. So only statements 1 and 2 are correct.

  • 1. Beyond about 3 degrees the terrestrial biosphere tends toward a net carbon source.
  • 2. Widespread coral mortality is expected.
  • 3. Not all wetlands would permanently disappear.
  • 4. Cereals could still be grown in many regions.

How you could have got this

  1. If you were sure statement 3 is not correct, (c) and (d) go: each of them includes 3.

    What you needed to know: Not all wetlands would permanently disappear.

    The red flag in statement 3 is “all”. In UPSC’s papers, statements with “all” were true 41% of the time (76 statements). A hint, not a rule.

  2. Then, if you were sure statement 2 is correct, (a) goes: it leaves 2 out.

    What you needed to know: Widespread coral mortality is expected.

Only (b) is left. You didn’t need statements 1 or 4.

Which options go is worked out from UPSC’s key and the options, not by a model.

Why each option is right or wrong
  • (a) Wrong. Widespread coral mortality is also expected.
  • (b) Right. Net carbon source land biosphere and widespread coral mortality are both expected.
  • (c) Wrong. Statements 3 and 4 are exaggerated.
  • (d) Wrong. Statements 3 and 4 are exaggerated.

Answer: UPSC’s key. Explanation: written by UPSC Grade, not by UPSC.

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Source: UPSC, Civil Services (Preliminary) Examination 2014, General Studies Paper I, Series A. The paper on upsc.gov.in.