Climate Change at the Poles
Understand how climate change is affecting polar regions — Arctic sea ice is shrinking dramatically (losing about 13% per decade since 1979), the Greenland and Antarctic ice sheets are losing mass and contributing to sea level rise, permafrost is thawing and releasing methane (a powerful greenhouse gas), and these changes create positive feedback loops where melting leads to more warming which leads to more melting
What a learner can do afterwards
- State that Arctic sea ice has been declining at roughly 13% per decade since 1979
- Explain the positive feedback loop: warming → ice melts → dark ocean absorbs more heat → more warming → more melting
- Describe at least two consequences of polar ice loss: sea level rise and permafrost thawing releasing methane
The lesson
The North and South Poles are covered in ice that took thousands of years to build up. Now that ice is disappearing fast. Scientists watching the Arctic Ocean have measured the sea ice shrinking year after year, and it keeps happening faster than it used to.
Picture two patches of ocean side by side: one covered in white ice, one open dark water. The white ice bounces sunlight back into space, but the dark water soaks up the sun's heat instead. Every patch of ice that melts uncovers more dark ocean, and that ocean absorbs more heat. The extra heat melts even more ice.
Scientists call this the ice-albedo feedback loop. Albedo just means how much light a surface reflects. Light ice has a high albedo; dark ocean water has a low one, so swapping one for the other changes how much heat Earth keeps.
Arctic sea ice is shrinking about 13% per decade, and every bit that melts uncovers more dark ocean, which traps more heat and melts even more ice.
Watch it
Where it sits
Where this leads
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8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.