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New NOAA sea level rise projections dramatically increase by 2100
February 22, 2017, Wakefield – The Rhode Island Coastal Resources Management Council (CRMC) will be using the latest global sea level rise (SLR) projections from the National Oceanic and Atmospheric Administration (NOAA) that anticipate a worst-case scenario of eight (8) feet (2.5 meters) by 2100. Unfortunately the Northeast Region will experience an additional 1 to 3 feet of relative SLR above the global projection due to several factors.
Sea levels in the Northeast region, as well as some other areas in the country, will rise significantly faster than the global average, according to a recent report from NOAA. See: https://tidesandcurrents.noaa.gov/publications/techrpt83_Global_and_Regional_SLR_Scenarios_for_the_US_final.pdf . Robert E. Kopp, an associate professor at Rutgers University’s Department of Earth and Planetary Science, coauthored the report, which details six scenarios intended to help decision makers plan for the future at both a regional and national level.
“Currently, about six million Americans live within about six feet of the sea level, and they are potentially vulnerable to permanent flooding in this century,” Kopp said. “Considering possible levels of sea level rise and their consequences is crucial to risk management.”
In Rhode Island there are approximately 7,000 people living within the 7-foot sea level rise inundation zone, according to a Rhode Island Statewide Planning report, available here: http://www.planning.ri.gov/documents/sea_level/socio/PDF%20-%20RI%2021%20Coastal%20Factsheet%20and%20Data%20Profile.pdf.
Under the Coastal Resources Management Program Section 145: Climate Change and Sea Level Rise, the CRMC considers future sea level rise for planning and coastal management, and uses the sea level change calculator provided by the Army Corps of Engineers, http://corpsclimate.us/ccaceslcurves.cfm to inform planning efforts. The CRMC has also formally adopted the GIS-based mapping tool STORMTOOLS, which was developed by URI Ocean Engineering for the CRMC as part of its R.I. Shoreline Change (Beach) Special Area Management Plan. STORMTOOLS illustrates flood inundation from multiple sea level rise scenarios and storm surge events. See http://www.beachsamp.org/stormtools/ for more, including storm surge inundation maps for the state.
The report, “Global and Regional Sea Level Rise Scenarios for the United States,” describes factors that are considered when estimating anticipated sea level rise such as ocean mass additions due mostly to melting of land-based ice; increases in global ocean volume due primarily to thermal expansion; and variability in ocean circulation. The report also reviews recent scientific literature on “worst-case” sea level rise projections and the possibility of rapid melting of the ice sheets in Greenland and Antarctica. All of the calculations and considerations resulted in evidence suggesting a most-dire projection of 8.2 feet of sea level rise globally by 2100 is more likely that previously thought.
The NOAA report gives a range of possible scenarios, from the low of 1 foot of sea level rise by 2100 to the 8.2 feet, which is 1.6 feet higher than the previous worst-case scenario reported in 2012 as part of the National Climate Assessment. The report also projects a global mean of 2.5 meters by 2100 and an additional 0.3 to 1 meter for the New England region, bringing the total sea level rise in the Northeast to 9.2 to 11.5 feet by 2100.In Rhode Island, approximately 154 square miles (14 percent) of the state’s 1,100 square miles of land area are mapped by FEMA as Special Flood Hazard Areas where there is a one percent (1%) chance of flooding in any given year. More than 16,000 buildings are located within these flood-prone areas with an additional 12,000 buildings located in areas mapped as a 0.2 percent chance of flooding (based on a CRMC GIS assessment of E911 data and flood zones), according to the RICRMP’s Section 145.