Read the passage and answer the questions given below it.
A river fed by ice can look its healthiest just when its future is least secure. That is the puzzle of the Himalayan glaciers. The Bhagirathi, a headstream of the Ganga, flows from the snout of the Gangotri glacier, and many northern rivers draw on ice in their upper reaches. Survey after survey finds that most Himalayan glaciers are thinning and retreating.
Retreat, oddly, does not at first mean less water. A glacier that melts faster sends more water downstream, so a river may run fuller for years while the ice that feeds it shrinks. Scientists call the turning point ‘peak water’. After it, the melt begins to fall, because less ice is left to melt. The extra flow is not a sign of health. It is a store being spent.
Nor does this matter most in the monsoon. During the rains, the plains hardly need the glaciers, since rainfall dwarfs their share. It is in the hot, dry weeks before the monsoon, when fields are parched, that meltwater attenuates the effects of the shortage. The Indus basin, with its drier lowlands, leans on this supply far more heavily than the Ganga basin, where rain carries more of the load.
Retreat brings a quicker danger too. Meltwater often pools in lakes behind loose walls of rock and debris left by the glacier. If such a wall gives way, the lake can empty within hours, and the flood that follows, a glacial lake outburst flood, tears down the valley with little warning. None of this means the rivers will soon run dry. When peak water arrives differs from basin to basin, and for some rivers no one can yet say whether it has already passed.
The tone of the passage can best be described as:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Sober concern, tempered by care not to overstate the danger
The writer is worried about the glaciers but takes care not to exaggerate.
- The concern is clear. The extra flow “is not a sign of health”, and outburst floods come “with little warning”. Sober means serious and calm, not emotional.
- The writer also holds back: “None of this means the rivers will soon run dry.” The last line admits what no one yet knows. To overstate is to make something sound bigger than it is.
- Tempered by means made milder by. The worry is made milder by this care.
Why the Other Options are Incorrect?
Option 1: Grim pessimism, tempered by a faint hope that the ice may one day return — Incorrect. Contradicted: Pessimism means expecting the worst. The writer does not expect the worst: “None of this means the rivers will soon run dry.”
Option 3: Calm optimism, tempered by unease about sudden floods in the valleys — Incorrect. Only partly true: Optimism means expecting things to go well. The writer is calm, but calls the fuller rivers “a store being spent”, which is not hopeful.
Option 4: Urgent alarm, tempered by doubt about what the surveys have found — Incorrect. Contradicted: The writer accepts the surveys: “Survey after survey finds” the glaciers are thinning. The writer shows no doubt about these findings.