In this activity, students learn about sea ice extent in both polar regions (Arctic and Antarctic). They start out by forming a hypothesis on the variability of sea ice, testing the hypothesis by graphing real data from a recent 3-year period to learn about seasonal variations and over a 25-year period to learn about longer-term trends, and finish with a discussion of their results and predictions.

This visualization, from the US Geological Survey, provides a simple schematic of the various pathways that water can take as it cycles through ocean, lakes, atmosphere, surface and ground.

This video examines how scientists learn about the effects of climate change on the water cycle and what those effects might mean for our planet.