--- title: "Climate change at the poles" description: "Understand how warming affects polar regions. September Arctic sea ice extent has declined over the satellite record since 1979, although individual years vary. Greenland and Antarctica are losing lan" canonical: https://lightmysky.com/learn/science/climate-change-at-the-poles-mt_Fqna9qHffr source: https://lightmysky.com/learn/science/climate-change-at-the-poles-mt_Fqna9qHffr.md retrieved: 2026-11-12 --- > **Agent view.** This is the Markdown twin of the page, for tools and assistants. > When to use this site, and the call that answers each job: https://lightmysky.com/agent-instructions.md > API description (OpenAPI 3.1): https://lightmysky.com/openapi.json · Authentication: https://lightmysky.com/auth.md > Pricing: https://lightmysky.com/pricing.md · Catalog: https://lightmysky.com/llms.txt · Full catalog: https://lightmysky.com/llms-full.txt > Every machine-readable file on this domain: https://lightmysky.com/.well-known/ai-catalog.json > Ask for Markdown with `Accept: text/markdown`, a `.md` address, or `?mode=agent`. # Climate change at the poles Understand how warming affects polar regions. September Arctic sea ice extent has declined over the satellite record since 1979, although individual years vary. Greenland and Antarctica are losing land ice, contributing to sea-level rise. Thawing permafrost can release carbon dioxide and methane. Sea-ice loss and greenhouse-gas release can each reinforce warming through different feedback loops. Subject: Science · Area: Polar Regions · Ages 9 to 11 Page: https://lightmysky.com/learn/science/climate-change-at-the-poles-mt_Fqna9qHffr ## Ready when they can - Describe the long-term decline in September Arctic sea ice extent since satellite tracking began in 1979, while recognizing that individual years vary - Explain the ice-albedo feedback: warming melts sea ice, exposed dark ocean absorbs more sunlight as heat, and the added warmth helps melt more ice - Explain how land-ice loss raises sea level and how permafrost thaw can release greenhouse gases that add to warming ## Lesson: The poles are warming up Sea ice floats on the ocean. It grows in winter and shrinks in summer. Satellites have tracked Arctic sea ice since 1979. Sea ice extent is the area of ocean with at least 15% ice cover. September extent has declined over many decades, although individual years vary. Comparing the same month across many years helps separate the long-term trend from seasonal changes. *(drawing: Read the chain from left to right. Added warming can lead back to more sea-ice melting.)* White sea ice reflects more sunlight than dark ocean water. When sea ice melts away, it exposes dark water. The water absorbs more sunlight as heat. Added warmth can melt more nearby ice. This repeating chain is the ice-albedo feedback. Albedo means how much sunlight a surface reflects. A positive feedback strengthens the starting change; positive does not mean helpful. Greenland and Antarctica have ice sheets on land. Both are losing ice overall. When ice is lost from land into the ocean, it adds water and raises sea level. Melting floating sea ice has little direct effect on sea level because it already pushes aside seawater. Permafrost is ground that has stayed frozen for at least two years. When it thaws, microbes can break down old plant matter. This can release carbon dioxide and, in wet conditions, methane. Both are greenhouse gases: they absorb some heat energy Earth gives off and slow its escape to space. Gases released from thawed ground can add to warming. Added warmth can thaw more ground, allowing more gas release. This is a permafrost feedback. It differs from the ice-albedo feedback: one involves greenhouse gases, while the other involves a change in sunlight reflection. **Example.** A made-up practice model starts with 90 ice units and removes 10 twice. Subtract once for each loss: 90 - 10 = 80, then 80 - 10 = 70. These are practice numbers, not satellite observations or a prediction. **Recap.** September Arctic sea ice has declined over decades. Sea-ice loss can add warming. Land-ice loss raises sea level. Permafrost thaw can release gases that add warming and cause more thaw. *This lesson, practice and flashcards were written for this dataset. Ice-unit calculations use made-up practice values.* ## Practice 8 questions on this page, each with its working shown. ## Needs first - [Glaciers & ice sheets](https://lightmysky.com/learn/science/glaciers-and-ice-sheets-mt_5_kErPeeNu) - [Polar Oceans and World Climate](https://lightmysky.com/learn/science/polar-oceans-and-world-climate-mt_g1qgxmlJQ2) ## Optional connections - [Climate Change Basics](https://lightmysky.com/learn/science/climate-change-basics-mt_DbI1kNg_0R) - [The Arctic Tundra](https://lightmysky.com/learn/science/the-arctic-tundra-mt_X4CJpPRxae) ## Opens up - [Polar Conservation & Future](https://lightmysky.com/learn/science/polar-conservation-and-future-mt_7QeiS95TRC) - [Forcing, Feedback and Climate Sensitivity](https://lightmysky.com/learn/science/forcing-feedback-and-climate-sensitivity-mt_os28W6fEkW)