From CoastalReview.org
The scientific panel that advises the state Coastal Resources Commission is showing in a new report how the findings of a 2022 federal report predicting sea level rise of more than a foot by 2050 apply to the Carolinas of the North.
Released in mid-October, the “North Carolina Sea Level Rise 2024 Science Update” is the product of the science panel following the commission’s 2022 charge to present any new or significant data and research on projections of sea level rise.
The commission was created in 1974 when the North Carolina General Assembly passed the Coastal Area Management Act, or CAMA. The 13-member commission designates areas of environmental concern, adopts rules and policies for coastal development within those areas, and certifies local land use plans. The Division of Coastal Management Staff of the State Department of Environmental Quality enforces the commission’s rules.
Scenarios and Tools The US Interagency Sea Level Rise and Coastal Flood Risk Task Force wrote “Global and Regional Sea Level Rise Scenarios for the United States,” which was published in February 2022 by the National Administration Oceanic and Atmospheric. Among the members of the task force are scientists from NOAA, NASA, the US Geological Survey, the Federal Emergency Management Agency, the Army Corps of Engineers, the Department of Defense and the Environmental Protection Agency.
“In recent years, confidence about the expected amount of sea-level rise by 2050 has increased,” the scientific panel summarized from the 2022 technical report in its October 2024 update. warming by 2100, the trajectories estimated by the 2022 sea level rise technical report show a sea level rise of 1 foot to 1.4 feet by 2050, compared to sea level in 2000.
“The actual amount will depend on future greenhouse gas emissions, and how much ice is lost from the Greenland and Antarctic ice sheets,” the science panel continued in its update. Projections for sea level rise beyond 2050 are less certain because they depend even more on future greenhouse gas emissions and the rate of ice loss from Greenland and Antarctica. However, rates of sea-level rise are expected to increase further in the second half of this century.”
In the scientific panel, Dr. Reide Corbett is dean and executive director of Integrated Coastal Programs at the Institute of Coastal Studies at East Carolina University’s Outer Banks Campus.
He told Coastal Review that sea level rise projections continue to improve as new data become available and as the scientific community gains a better understanding of the global processes that change sea level at different spatial and temporal scales. time.
The state’s science panel used the best available and most recent data to provide this 2024 Sea Level Rise Update, Corbett continued, adding that “It is critical that our communities work with the most informed projections as they develop action plans for building more resilience across our coast.”
The strongest and most significant message Corbett said he sees coming from the 2024 update and other recent reports is that North Carolina should plan for at least 1 foot of sea level rise by 2050. There little deviation in this value if projected from tide gauges or using numerical models, Corbett added
“This is a reality that we need to start planning for today,” he said. “A 1-foot rise in sea level will significantly increase the number of days coastal North Carolina will experience tidal flooding. Communities must begin to build these challenges into their land use plans, stormwater plans, and hazard communication to residents.
Division of Coastal Management Director Tancred Miller explained to Coastal Review that the scientific panel is defining sea level rise as an increase in mean sea level relative to a specific reference.
Relative sea level is the combination of three main factors: global sea level, vertical land movement, and oceanographic effects. These parameters are usually discussed in terms of the rate of temporal change, usually expressed in millimeters per year, he said.
“Along the North Carolina coast, sea level is rising, and the rate of rise varies by location. There are two main reasons for this variation along different parts of our coast: vertical land movement and the effects of ocean dynamics,” Miller continued.
He explained that this latest update highlights that tide gauge observations and modeling for all scenarios are about the same by 2050, “indicating that we are on track for at least a foot of sea level rise by the year 2050”.
Miller noted that 2050 is only 25 years from now. “To prepare for this requires community involvement, planning, mitigation and adaptation to begin now,” Miller said.
To help better plan for sea-level rise, the Coastal Resources Commission tasked its science panel in 2022 with providing periodic updates to support what it called “informed planning and decision-making.”
The charge includes a request that the scientific panel annually review any “new and significant scientific literature and studies that address the range of implications of sea-level rise at the state, sub-regional, and local scales.” If there is enough new information to warrant an update, the panel should present those findings to the commission.
Miller said for the scientific panel to follow the directive directly, the team of scientists held a series of meetings earlier this year to share and discuss any recent data on sea-level rise.
“Given that the hard work of preparing sea-level rise projections based on the latest science has already been done” by the task force, the scientific panel summarizes the key messages detailed in the 2022 technical report.
The science panel also provides a brief summary of the regional sea level rise projections most relevant to North Carolina and provides updated sea level rise projections and estimates of high wave inundation frequencies for the Duck, Beaufort and Wilmington, all based on data from the 2022 technical report.
The science panel sent out a draft sea-level rise science update for comment this spring.
The document underwent a number of changes based on public feedback, including adding a paragraph listing some of the main impacts of sea level rise and adding the names of the different scenarios in the 2022 technical report – low, medium-i low, intermediate, medium-high and high — and we refer to these for clarity.
“The five sea-level rise scenarios encompass the range of sea-level rise that can be expected under the emissions and warming scenarios considered in the Intergovernmental Panel on Climate Change’s Sixth Assessment Report,” or IPCC, the scientific panel notes in updating it. The IPCC was created by the United Nations to assess the science related to climate change.
“We also added text to explain how these scenarios relate to the emissions pathways and warming scenarios used in the Intergovernmental Panel on Climate Change report,” the new update continues. And it provided more detail on long-term scenarios up to 2100.
The science panel noted in its update that, although summarizing the latest science on how these impacts will affect the state “is beyond the scope of the Science Panel’s sea level rise update fee, we refer stakeholders to the coastal aspects of the 2020 Climate Risk and Resilience Assessment Plan, and accompanying or similar documents (and updates), for a more comprehensive discussion of the impacts of sea-level rise, based on the latest science; to facilitate effective adaptation and mitigation planning.
The first report the scientific panel, along with six other contributors, issued was in March 2010 titled “North Carolina Sea Level Rise Assessment Report,” under the commission’s direction. The scientific panel recommended that the report be re-evaluated every five years.
In April 2012, the panel released an addendum to the report in response to questions from the commission.
That report was met with opposition from certain groups, resulting in a June 2012 law that placed restrictions on how sea level data was collected and used by state agencies and local governments.
The panel published an update in 2015 of the 2010 report.
“The next update was planned for 2020. However, due to the COVID pandemic, the 2020 update was postponed. In 2022, the CRC issued a revised scientific panel fee,” Miller said.
The Division continues to accept public comments on the newly released update. Send comments to DCMcomments@deq.nc.gov. List “2024 Sea Level Rise Science Update” in the subject line. “Comments regarding the final report serve simply as an opportunity for citizens to provide input on the completed work and will be provided to the panel for consideration,” Miller said.
