Every year nationwide, sea level rise caused by global warming is directly responsible for hundreds of high tide floods like those in Workman’s neighborhood. Coastal planners are grappling with the worsening problem, which is most pronounced along the East and Gulf coasts, where sea level rise has been fastest and where land is sinking and eroding away.
A large full moon called a “supermoon” pulled tides higher from Sunday until Wednesday, triggering the latest episode of sweeping coastal flooding. Such floods are most common in the spring and the fall. As high tides in the spring and fall have been causing worsening floods, people have taken to calling them “king tides.”
Out of 15 floods caused by high tides at locations monitored with tide gauges, a Climate Central analysis of federal data found 12 were driven by the effects of greenhouse gas pollution on sea levels.
As sea level rise has accelerated during the last half century, high tide
flooding has become routine in some places and will continue to get worse. Climate change pushed high tide waters above local flood levels for three-quarters of the thousands of tidal floods in America from 2005 to 2014,
analysis by Climate Central in February showed. That was up from less than half in the 1950s.
High tide floods are rarely deadly unless they coincide with a powerful storm. These minor floods block roads, including the only freeway connecting Tybee Island in Georgia from the mainland. They can swamp basements and storefronts, which occurs regularly in Annapolis, Md. And the salt they bring
can kill forests and affect farmland.
Economic impacts of these floods can be difficult to assess. They include costs to retailers that can’t open their doors on some days and damage caused by floods to cars and buildings. Fixes are expensive: infrastructure improvements needed to ease regular flooding in Norfolk, Va., have been
estimated $1 billion.
Aside from nuisance flooding, sea level rise causes property damage and jeopardizes lives by pushing storm surges higher — including the deadly pulse of
water wrought by Hurricane Sandy. Global warming also means bigger storms and heavier rain.