Dwindling Sea Ice
Students learn that Arctic sea ice is shrinking due to warmer atmospheric and ocean temperatures as well as the ice-albedo feedback.
Engage students by comparing maps of Arctic sea ice change over time.
- Compare maps of how Arctic sea ice has changed over the past few decades using one or more of the maps and animations below. Ask students how Arctic sea ice during winter compares to summer. Ask students how the amount of Arctic sea ice left at the end of the summer melt season has changed over many years.
Explore sea ice by searching for answers to sea ice questions at the National Snow and Ice Data Center.
- Ask students to brainstorm questions that they have about sea ice based on their map comparisons. List questions and then have students read All About Sea Ice and Climate Change in the Arctic (on the National Snow and Ice Data Center website) to see how many of the questions can be answered by those articles. If questions remain after reading the two articles, consider extending this activity by having students create a list of search terms that will help them find answers through an Internet search engine and then performing the search and reporting to their classmates what they have found.
Elaborate by having students model the ice-albedo feedback.
- Describe to students that one reason Arctic sea ice melt has been so rapid is because melt of white ice causes less solar energy to be reflected back out to space and so more heat is absorbed in the Arctic leading to more warming. Have students build the model described in the Sea Ice and Heat: A Vicious Cycle activity to explore this phenomenon. Discuss how this model is like, and unlike, the way real Arctic sea ice is affected by the Sun's energy. Have students modify the model to address a particular question that they have about the interaction of sea ice and energy from the Sun.
Evaluate student learning by having students apply their understanding of sea ice change over time to a real-world situation.
- Ask the class how continuing summer sea ice melt could affect polar bears who roam the sea ice looking for food. To provide context, have students read Polar Bears on Thin Ice.
- Have each student write an if/then statement about what polar bears would do (and where they would go) when ice retreats during summer. (If ice melts during summer more and more each year, then polar bears will ...)
- Have students look at the Polar Bear Tracking Interactive and write a paragraph describing the data and stating whether it is consistent with their hypothesis or refutes their hypothesis. Student hypotheses may include that the bears will live on the smaller sea ice, that bears will move onto shore, or that they will die. The data in the interactive show that bears move onto the shrinking sea ice, further from land. (Note: These data shows the tracks of four bears. Research continues on whether polar bears will be able to survive in a warmer world.)