How likely is a 1-3 meter sea level rise in the next 50 or 100 years? While it is certain that the rate of sea level rise is increasing, predicting exactly when a 1-meter rise could occur under projected warming scenarios is complicated, because there are so many factors involved. The UN's Intergovernmental Panel on Climate Change (IPCC) predicts 2-4 degrees warming by the next century, but we still have an incomplete understanding of how quickly continental ice sheets will melt under projected temperature scenarios. The panel concluded that it could not "provide a best estimate or an upper bound for sea level rise" over the next century due to their lack of knowledge about Earth's ice. We know that there is 5-6 meters worth of sea level in the Greenland ice sheet, and 6-7 meters in the West Antarctic Ice Sheet. (The much larger East Antarctic Ice Sheet is probably not vulnerable to widespread melting until beyond the next century). However, when the last ice age ended around 12,000 years ago, rapid melting of continental ice sheets caused a sea level rise of 11 mm a year- or a meter in 100 years, suggesting to some researchers that a 1-meter rise in sea level in the next 100 years is a realistic scenario.

Earth System Impacts of Sea Level Rise

Watch "Antarctic Ice: Sea Level Change" from PBS LearningMedia to learn what might happen to the global sea level if atmospheric warming collapses Antarctica’s West Sheet. What is the different effect on sea level between the breaking and melting of ice sheets already floating on seawater and the breaking and melting of ice sheets sitting on bedrock?

A 1-meter rise in sea level would impact the coastline and loss of the critical coastal wetland habitat. Watch the video "Intertidal Zone" and consider the functions of a wetland that could be compromised by coastal inundation because of sea level rise.

Now view the "Coastal Geological Processes" interactive and hypothesize how a rise in sea level would impact coastal processes.

Consider the role of wetlands for the atmosphere, biosphere, lithosphere, and hydrosphere. Watch "Hurricane Katrina: Wetland Destruction" to learn about the role of wetlands with respect to storm surges such as the surge that occurred in New Orleans during Hurricane Katrina.

Finally, explore the "Environmental Hazards at the Coast" interactive. Identify the health and human hazards that could be exacerbated by a 1-meter sea level rise.

Earth System Impacts of Sea Level Rise

"From the Mississippi Delta to the Maldives Islands off the coast of India to the multitude of lying coastal areas around the world, it's estimated that over 100 million lives are potentially impacted by a three-fold increase in sea level."
- Dr. Waleed Abdalati (2005)

One expected impact of sea level rise is an increased risk of storm surges. Learn more about this danger by reading "NASA Looks at Sea Level Rise: Hurricane Risks to New York City".

Despite the difficulties faced by scientists in predicting the rate and amount of sea level rise Earth will experience in the next decades, two coastal cities, Seattle and New York City, are developing strategies to both decrease greenhouse emissions and prepare for future climate change challenges. Read "A Tale of Two Cities" to learn how both cities are using space-based data to plan for future climate change.

A Tale of Two Cities

For further information on how New York City is taking steps to mitigate serious impacts of climate change, read this news brief from NASA.

How can you engage students in thinking and learning about the human impact of sea level rise in different parts of the United States?