Rising Sea Level

Rising sea level doesn't seem too important to those of us here in central Pennsylvania.  Those closer to the ocean are a bit more concerned.  When ice melts, water rises.  No matter what you believe to be the cause of global warming, it's difficult to deny that the change is happening.  Numbers don't lie.  The ten warmest years on record globally have all occurred since 1998, the warmest three being 2014, 2005 and 2010. 

The numbers are not just seen in rising temperatures.  New York City's subway system is now twenty times more likely to flood than it was in the late nineteenth century, according to the conclusions of a study by the American Meteorological Society (AMS).  Though the average annual increase might seem small, the cumulative rise makes a difference, especially during storms.  "By raising the water level, sea level rise provides storms with a higher launching pad for storm surges," explains Climate Central's Andrew Freeman.  Places like New York City are not just inconvenienced; it can result in damages and restoration costs that are staggering.  Widespread subway flooding that was rare five decades ago happens every few years now.  And it's not uncommon for a single storm to cause hundreds of millions in damage.

Though the Netherlands has lived with the ocean on its literal doorstep for centuries, much of the rest of the world has been presented with new and expensive challenges trying to keep the ocean at bay.  "Today's coastal infrastructure is steadily losing ground due to relative sea level rise," said co-author of the AMS study, William Sweet, an oceanographer at the National Oceanic and Atmospheric Administration.

A recent report from the National Research Council also confirms the serious problems confronting the Atlantic and Gulf Coasts' barrier islands.   Most of our popular beach communities set on these skinny islands.  Running from Cape Cod to the tip of Florida and west to Texas, barrier islands are just what the name implies.  They are relatively narrow islands (that are best described as over-gown sandbars) that set between the open ocean and the actual mainland.  Much like the floodplains of large rivers, the constant erosional force of the water alters the shoreline every day.

The population of these coastal areas has grown rapidly in the last fifty years and, even though we should know better, we have built resorts, hotels, condos and a host of other tourism-related developments almost up to the shoreline.  Protected naturally by a mound of sand called a back dune, these islands are sheltered from the worst stormy weather if we don't build in front of the protective dune.  Most seaside communities have ignored the importance of that natural protection, cents overwhelming common sense.  While inconvenient and often expensive, rising sea level presents some island nations with a much more serious problem.  Two of the most endangered island systems, the Maldive Islands and the nation of Tuvalu are fighting for survival.  Beyond the chronic flooding and accelerated erosion, salt water intrusion is ruining both their fresh ground water and their agricultural areas.  Tuvala, New York and Ocean City, three very different places, share one notable similarity – an uncertain future.