A recent article "Rising seas may cost Delaware $9B over 20 years" contained much questionable information from a new study, "HIGH TIDE TAX", from "The Center for Climate Integrity" which "supports litigation and advocacy to hold the fossil fuel industry accountable" for climate change. They want to tax and sue fossil fuel companies, but who would actually pay the cost? The people, of course, in higher costs for everything.
The $9 Billion is not an estimate of actual damages which might occur but an estimated cost to build 941 miles of seawalls "to hold off climate-driven floodwaters."
But according to NOAA, Delaware only has 381 miles of coastline, including the extra length from tidal inlets.
Sea level off Delaware has risen about 1 foot in the last 100 years, partly because the land is sinking, and will likely rise another 3 inches in 20 years.
But compare this to the 7 foot storm surge at Lewes DE from "The Gale of 1878" which brought hurricane force winds and flooding to all three counties.
Sea walls may be a good idea in some places but the real concern should be storms which could happen now, not in 20 or 100 years.
Prepare for storms and this will take care of sea level rise.