Storm surge on a Louisiana highway shows the affects of rising sea levels.
Many people are interested in climate change and how a changing climate will affect the ocean. With the majority of Americans living in coastal states, rising water levels can have potentially large impacts. Scientists have determined that global sea level has been steadily rising since 1900 at a rate of at least 1 to 2.5 millimeters (0.04 to 0.1 inches) per year.
Sea level can rise by two different mechanisms with respect to climate change. First, as the oceans warm due to an increasing global temperature, seawater expands—taking up more space in the ocean basin and causing a rise in water level. The second mechanism is the melting of ice over land, which then adds water to the ocean. The Intergovernmental Panel on Climate Change predicts that total global-average sea level rise from 1990 - 2100 will be 110 to 770 millimeters (4.3 to 30.3 inches).