Sea levels rose about 8 inches globally and about 1 foot on the Eastern Seaboard in the past century. What would happen to Ipswich if catastrophic predictions for the 21st Century are realized?
Climate Central’s new global Coastal Risk Screening Tool generates customizable, localized maps of projected sea level rise and coastal flood risks by year, water level, and elevation. Coastal Risk Screening Tool users begin their exploration with three map choices:
- The year map allows users to explore coastal flood risk and sea level rise projections by decadal year. See Map
- The water level map allows users to explore what land is at risk from specific water levels (decimal feet, meters) that could be reached through combinations of sea level rise, tides, and storm surge. See Map
- The elevation data map highlights how Climate Central’s improved elevation data indicates far greater global threats from sea level rise and coastal flooding than previously thought, and thus greater benefits from reducing their causes.
In a December 6, 2012 report, NOAA’s Climate Program Office collaborated with authors from NASA, the U.S. Geological Survey, the Scripps Institution of Oceanography, the U.S. Department of Defense, the U.S. Army Corps of Engineers, Columbia University, the University of Maryland, the University of Florida, and the South Florida Water Management District in a study that observed that global sea level rise has been a persistent trend for decades, and is expected to continue beyond the end of this century. Their report gives a very high confidence (greater than 90% chance) that global mean sea level will rise at least 8 inches (0.2 meter) and no more than 6.6 feet (2.0 meters) by 2100.
Recent reports suggest that these predictions may be conservative. There is a widespread consensus that substantial long-term sea-level rise will continue for centuries to come, resulting in partial deglaciation of the Greenland and West Antarctic ice sheets, given a predicted global average temperature increase of 1–4 °C., increasing sea levels 3 to 20 ft. during this millennium.
The images below link to an interactive map created by Climate Central that shows the impact of sea level rise in increments from one foot to ten feet.
Lowest sea level change scenario: 8″ rise
Intermediate-low sea level change scenario (1.6 feet)
Intermediate-high sea level change scenario (3.9 feet)
Highest sea level change scenario (6.6 foot rise)
The eight coastal communities from Salisbury to Rockport, the “8 Towns by the Bay,” are exposed to varying degrees to coastal flooding resulting from sea level rise and storm surges. Elevation analysis of this region identifies those areas at risk of inundation at flood levels of 3 meters, 3.5 meters, and 4 meters above current sea levels.
Coastal areas are particularly at risk from sea level rise associated with climate change. More specifically, sea levels are expected to rise about 1 meter over the next 100 years, permanently inundating many low-lying areas. In addition, more frequent and more severe storms are expected to cause short-term flooding of coastal areas above and beyond the level of flooding caused by rising sea levels. This study considers the impact of sea level rise and storm surge flooding on the built and natural environments of 8 coastal towns along the northern portion of the Massachusetts coastline, Salisbury, Newburyport, Newbury, Rowley, Ipswich, Essex, Gloucester, and Rockport, the “8 Towns by the Bay.”
Of 388 sq. km. included in the eight towns, 83 sq. km. will be flooded under the 3 meter scenario, 94 sq. km. under the 3.5 meter scenario, and 102 meters under the 4 meter scenario, or 21%, 24%, and 26%, respectively.