The loss of Arctic sea ice due to global warming is widely recognised as the greatest threat to the polar bears' survival.
大家普遍认为全球变暖导致的北极冰雪融化是北极熊生存的最大威胁。
2
Scientists fear that the shifting Arctic climate could threaten the species' survival.
科学家们担心，北极气候的不断变化可能会威胁物种的生存。
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The Arctic is populated with people of different nationalities. The Antarctic, in contrast, has no permanent residents because the climate there is unfavourable to human survival.