Coastal cities will be regularly submerged by rising tides. A new study by the Union of Concerned Scientists predicts that over the next 20 years tidal flooding will increase from occasional to chronic, and then from chronic to incessant. Melanie Fitzpatrick, co-author of the report Encroaching Tides, states that many people have been surprised that floods in their homes are not caused by rain, but by rapidly rising sea levels.
Climate change does not always play out as scientists expect because humans do not understand how all of earth’s systems work together. For example, Antarctic ice is growing as Arctic ice is melting. Surface ocean temperatures have risen, but the deep, deep parts of the ocean remain cool. It is ocean surface temperature that is a fundamental factor in determining climate, and ice is melting faster in the north than it is being frozen in the south. As a result, ocean levels are rising.
On some South Pacific islands people are losing the land on which they live. The people of Kiribati became the first recognized climate change refugees. The islands of Tuvalu, Tokelau, the Maldives and the Marshall Islands are looking at ways to relocate populations as their homelands disappear under the waves.
The United States has mostly seen itself as unaffected by rising oceans. However, people in Florida, Louisiana and Maryland are experiencing the effects of climate change and beginning to worry about their communities, towns and cities. The problem is not that coastal cities will be completely sunk beneath the ocean like a modern-day Atlantis. Instead, the rise in ocean levels is causing higher high tides, especially the spring tides at the full moon.
Recent research has confirmed that the rise in sea levels has aggrandized the high tides. The Union of Concerned Scientists studied 52 locations using tidal gauges installed by the NOAA. The tidal gauges have been collecting tide data for a century. The UCS released a report that predicts 180 floods will occur in Annapolis, MD every year due to high tides by 2030. Sometimes floods will strike twice a day as high tides are approximately 12 hours apart. By 2045 more cities will be undergoing regular flooding. Washington, DC, Atlantic City, NJ, Annapolis, MD and many other coastal locations on the Atlantic Ocean and the Gulf of Mexico will experience nearly daily, damaging floods.
The UCS researchers originally looked at the effect of sea level rise on increased storm surges and hurricanes. Super storm Sandy illustrated the devastation wrecked by sea inundation. They realized that the more frequent tidal floods, though smaller in volume, would have a much greater impact on American communities. They may render parts of major cities uninhabitable. They will also stress storm drain systems and aggravate ocean pollution issues.
The states most at risk are: Florida, Louisiana, North Carolina, New Jersey, New York, Virginia, Texas, Maryland, Connecticut and California. The Mid-Atlantic States are particularly vulnerable with some cities predicted to flood on multiple days per week.
Coastal communities need to plan for tidal flooding by investing in marshes, sea-walls and levees to mitigate inundation. In New York City, work is already being done to raise roads. Annapolis and Baltimore are developing multiple ways to adapt to frequent flooding. Paul Wolff, a council member in Tybee Island, Georgia, describes tidal floods as a “slow motion storm surge that doesn’t go away,” and says that this is happening in real life, not in a fictional scenario.
The oceans have risen eight inches since preindustrial times. NOAA has already been tracking “nuisance floods;” the small tidal floods that make life difficult and uncomfortable but do not create devastation. NOAA determined that nuisance floods are now occurring ten times more often in some places than they did in the 1960s. They also expect the number to increase.
Cities should anticipate the hazards associated with sea level rise. The reports by the UCS and NOAA provide the information necessary for communities to prepare. Many states already experience an increase in tidal flooding. Soon, coastal cities will be regularly submerged by rising tides.
By: Rebecca Savastio