Q. Scientist studied the vernal window – transition period from winter to the growing season.
They found that warmer winters with less snow resulted in a longer lag time between spring events and a more protracted vernal window. This change in the spring timetable has ecological, social and economic consequences – for agriculture, fisheries, and tourism. As the ice melts earlier, the birds don’t return, causing a delay or lengthening in springtime ecological events.
Q1. With reference to the above passage, the following assumptions have been made:
1. Global warming is causing spring to come early and for longer durations.
2. Early spring and longer period of spring is not good for bird populations.
Which of the above assumptions is/are correct?
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2
Question from UPSC Prelims 2023 CSAT
Model Answer:
Q1: Correct Answer – (a) 1 only
Explanation –
To determine the correct answer, let’s analyze each assumption based on the information provided in the passage:
1. Global warming is causing spring to come early and for longer durations.
The passage mentions that warmer winters with less snow result in a longer lag time between spring events and a more protracted vernal window. This implies that the transition period from winter to the growing season (spring) is extended due to warmer conditions. Although the passage does not explicitly use the term “global warming,” it is reasonable to infer that warmer winters are a result of global warming. Therefore, this assumption is correct.
2. Early spring and longer period of spring is not good for bird populations.
The passage states that as the ice melts earlier, the birds don’t return, causing a delay or lengthening in springtime ecological events. This indicates that the change in timing affects the birds’ behavior, but it does not explicitly state that these changes are harmful or “not good” for bird populations. It only mentions a delay in their return, which could have various implications, not necessarily negative. Therefore, this assumption lacks sufficient support from the passage.
Based on this analysis, the correct answer is:
(a) 1 only – This choice is correct because the first assumption is supported by the passage, while the second assumption is not conclusively supported.