Sea level rise poses a significant threat to historic US towns. Many of these towns are located on the coast and are already experiencing the effects of climate change, such as increased flooding and erosion. If sea levels continue to rise, these towns could be completely submerged underwater.

Here are some of the historic US towns that are most at risk from sea level rise:

* Charleston, South Carolina: Charleston is a beautiful and historic city that is located on the Atlantic Ocean. However, the city is sinking, and rising sea levels are making flooding more frequent and severe. In 2015, Charleston experienced its highest flood on record, which caused over $1 billion in damage.

* Norfolk, Virginia: Norfolk is a major port city located at the mouth of the Chesapeake Bay. Rising sea levels are causing the bay to rise, which is flooding the city's waterfronts and damaging infrastructure. The city is already spending millions of dollars on seawalls and other flood control measures, but it is estimated that these measures will not be enough to protect the city from future flooding.

* Miami, Florida: Miami is a global tourist destination that is known for its beaches and sunny weather. However, rising sea levels are causing the beaches to erode and the city's infrastructure to flood. The city is already working to address these issues, but it is estimated that it will need to spend over $1 billion each year to keep up with the rising sea levels.

* New Orleans, Louisiana: New Orleans is a historic and vibrant city that is located on the Mississippi River. The city is below sea level and is protected from hurricanes and flooding by a system of levees. However, these levees are aging and the city is sinking, which is making it more vulnerable to flooding. In 2005, Hurricane Katrina breached the levees and flooded the city, causing catastrophic damage.

* San Francisco, California: San Francisco is a beautiful and iconic city that is located on the San Francisco Bay. Rising sea levels are causing the bay to rise, which is flooding the city's waterfront areas. The city is already working to address these issues, but it is estimated that it will need to spend billions of dollars to protect itself from future flooding.

These are just a few of the many historic US towns that are at risk from sea level rise. If sea levels continue to rise, these towns could be completely lost within a century.