Most experts agree that average sea levels have risen worldwide since the beginning of the twentieth century. In the last few decades the rate of that change has accelerated. Knowing these facts marks the first step—but only the very first—in calculating likely sea level rise impacts for your unique coastal community.
“The global projection is a starting point,” says Doug Marcy, a coastal hazards specialist at the NOAA Coastal Services Center. “Local data must be incorporated to make a meaningful projection for your community.”
Marcy and his fellow scientists at NOAA are encouraging communities to use the scenario approach in their planning strategies. Instructions for this task are provided in a new NOAA publication, Incorporating Sea Level Change Scenarios at the Local Level.
“Projections represent an imperfect science,” continues Marcy, “and there are many moving parts. For long-range planning in particular, focusing on a range of possibilities, and the associated range of impacts, makes more sense as opposed to using one number.”
Generally the more pertinent the information that is included in the projections, the more accurate the effort. This publication provides the information needed to create appropriate scenarios for community use. A few tips from the guide:
Consider the scale and details that will go into your scenarios – Have you collected the most detailed, reliable, and comprehensive data? Which sorts of local vulnerabilities are most important for you to document? Should the scenario include just one coastal community or several nearby?
Include all pertinent sea level rise variables – Are you factoring in high daily tides, king tides, extreme storm events, riverine floods, and other important influences?
Consider how your community will respond to the scenarios – Will officials make plans through an executive order, regulations, or just a recommendation? How will cost factors play into the local approach?
“The eight-step approach recommended in our guide takes work and time,” admits Marcy. “But it will be much better than a ‘one size fits all approach’ in terms of helping your community stay more resilient in the long term.”
“Incorporating Sea Level Change Scenarios at the Local Level” is available for download at www.csc.noaa.gov/slcscenarios.
