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?

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 Antartic 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.

one_foot_rise
The lowest sea level change scenario (8 inch rise) is based on historic rates of observed sea level change. The causeway on Jeffreys Neck Rd. is below sea level.
two_foot_rise
The intermediate-low scenario (1.6 feet) is based on projected ocean warming. Crane Beach is no longer accessible.
four_foot_rise
The intermediate-high scenario (3.9 feet) is based on projected ocean warming and recent ice sheet loss. Great Neck is an island, separated completely from the town.
six_foot_rise
The highest sea level change scenario (6.6 foot rise) reflects ocean warming and the maximum plausible contribution of ice sheet loss and glacial melting. Water Street and much of Argilla Road are submerged.
10_feet_downtown
This map is a closeup of downtown Ipswich with 10 feet of sea level rise. Sections of Market Street, Hammatt Street, Brown Square, South Main, Water Street and East Street would be under water. Until the middle of the 19th Century, the area around Farley Brook was a wetland that extended from Mineral Street to where it empties into the Ipswich River behind Market Street. Central Street and Brown Square came into existence in the mid-19th Century after the wetland was drained. Much of Farley Brook now runs underground. In coastal areas, sea level rise can contribute to freshwater bubbling up from underground, which would more than double the flooding caused by intruding seas alone.
2006 Ipswich Mothers Day Flood . Photo courtesy Ipswich River Watershed Association
Well before sea level rise inundates downtown, Ipswich is likely to experience more catastrophic flooding from increased water levels in the Ipswich River, which is brackish until it reaches the EBSCO Dam. The Mothers Day Storm of 2006 gave the town a wake-up call. Photo courtesy of the Ipswich River Watershed Association.

Storm Surge

Abstract from Effects of Storm Surge and Sea Level Rise on “Eight Towns by the Bay” P. Curtis, C. Dicesare, T. Howington, Y. Kocak, M. Zubair December 16, 2009 – Salem State College

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.

Flooding on Jeffreys Neck Road, Feb 6, 2016 high tide. Photo by Ipswich Emergency Management, courtesy of TheLocal.Ne.IS
Flooding on Jeffreys Neck Road, Feb 6, 2016 high tide. Photo by Ipswich Emergency Management, courtesy of TheLocal.ne.ws

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