Title: Sea Level Rise | Smithsonian Ocean
Headings: Smithsonian Ocean
Smithsonian Ocean
Sea Level Rise
History of Sea Level Rise
Last Glacial Period
Sea Level on the Rise
Why is it Rising?
Thermal Expansion
Melting Ice
Other Contributions
Modern Sea Level
Measuring Global Sea Level
Changing Regional and Local Sea Levels
Impacts
Storms and Flooding
Changing Coastlines
Saltwater Intrusion
There's No Place Like Home
Regional Case Studies
Florida and the U.S. Gulf Coast
Island Nations
Alaska
River Deltas
Future Sea Level & Adaptation
Reducing Emissions
Holding Back the Sea
Moving Inland
Additional Resources

Content: Global warming associated with human activities causes sea level to rise in several ways. Thermal Expansion
One property of water is that warm water takes up more space than cold water. So as the ocean warms from climate change
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, seawater expands to fill a greater volume and takes up more space. This is called thermal expansion, and it is responsible for one-third of sea level rise to date. The idea that water expands when heated seems strange, but it is a property of most objects that occurs at the molecular level. When water molecules are heated, they absorb energy. That energy causes the molecules and atoms to move around more and, in the process, take up more space. If you heat up a cup of water, the small molecular expansions don't add up to a difference we can detect by eye. But when you have vast numbers of water molecules, like in the ocean, the tiny expansions add up to something we can see. Thermal expansion is an ongoing