Students view a slideshow about where sea ice comes from and where it goes when it melts. Make predictions and observations in a hands-on experiment about the effects of melting glaciers and sea ice. Discuss the results and how they illustrate the impacts of rising sea levels on coastlines around the world.
There are two main causes of rising sea levels. Glaciers and ice sheets are large bodies of ice that are found on land. As the Earth warms, glaciers and ice sheets are melting at a faster rate than before. This meltwater flows into oceans, raising sea levels. Generally, when ice floats, it displaces an equal volume of water as the volume of water it creates when it melts, so it should not increase sea levels.
Secondly, as the Earth warms, oceans are also absorbing more heat due to the albedo effect (see Extensions). When water gets warmer, it expands, also causing sea levels to rise. This will affect many people who live in communities along the coast