Some big environmental news lately has concerned the fact that the ocean level is rising. Well we knew that already, right? What we didn?t know is that the ocean level off the east coast of the US (from Cape Hatteras, North Carolina, to Boston, Massachusetts) is rising 2 to 3 times quicker than average global water levels — about 2 – 3.7 millimeters a year as opposed to 0.6 – 1 millimeters a year globally.
There are different theories regarding sea level rise. The two big camps tout human-induced climate change or state that it is part of a natural cycle. As usual, the truth is probably somewhere in the middle.
Three Reasons For Global Sea Level Rise
Melting Ice Caps
This one is a no brainer — environmentalists and scientists have been stating this for years. About 1.7% (5,773,000 cubic miles) of the Earth?s water is stored in ice caps and glaciers, enough to raise the sea level by 230 feet if they all melted away.
Water is a strange molecule. Most molecules expand as they warm and contract as they cool. Water does this to some degree, but for some reason (any chemists out there please chime in!), water is most dense at 4 degrees Celsius. Any warming or cooling from that point causes it to expand. According to National Geographic, sea level temperatures have risen globally by about 0.1 degrees Celsius over the past century. The ICC projects that thermal expansion will account for roughly half of the average rise by 2090.
Yes, groundwater is now said to have a role in rising ocean levels. The rationale is that any water pumped from the ground will eventually find its way to the ocean. This has largely been ignored by the forecast models that assume groundwater extraction will be balanced by river damming.
Using a model that projects climate impacts, Yadu Pokrel of Rutgers University added human water use components and assumed that global water demands not met by surface water come from groundwater. The result? Groundwater runoff accounts for approximately 34% of annual sea level rise.
Why Are Sea Levels Rising Faster Along the East Coast?
It has been suggested that the acceleration of sea level rise along the east coast is consistent with slowing of Atlantic currents. These currents are driven by the sinking of the cold, denser water in the arctic. The warmer arctic waters are not sinking as quickly, leading to slower currents and a ?hotspot? in rising sea levels. By 2100, it is predicted that sea levels along the east coast will have risen an additional 8 to 11 inches along with the average global sea level rise.
What Can Be Done?
States along the east coast are currently exploring ways to deal with the rise.
The Boston Globe reports that Massachusetts has been preparing for sea level rise by changing development codes in Flood Zones and inspecting utility systems statewide.
In North Carolina, a group called NC-20, which is (according to the Insurance Journal) made up of the 20 oceanside counties in NC and favors coastal development, protested these findings. It lead to the NC State legislature exploring a bill (that did not pass) that would simply have made this rising sea level prediction illegal. Confused? Please allow Stephen Colbert to explain.
However, North Carolina did recently pass a law that bans lawmakers from making sea level policy changes for the next 4 years.
Written by: Chris Hollinger