4 December 2012
New Science On Sea Level Rise Indicates Greenland And Antarctic Ice Melt Increasing.
Posted by Dan Satterfield
Superstorm Sandy was a devastating tragedy, but if something like that could have a silver lining then the new public awareness of sea level rise is perhaps it. Just weeks after Sandy, comes a major paper in Science. The paper is the result of a collaboration by the top experts studying the mass balance of polar glaciers. If you get a chance, pick up a copy of Science and read Richard Kerr’s summary of the paper (as well as the paper itself actually).
While there has been a lot of disagreement among the different methods of measuring the ice loss in polar regions, it now looks as if there has been real progress. The project was called IMBIE or Ice sheet Mass Balance Inter-comparison Excercise. In short all the researchers got together and reconciled their data.
Ice regions at the poles are losing 344 billion tons of ice every year. 263 billion tons of that melt is in Greenland, and all that melting ice is responsible for 20% of the observed sea level rise. The rest is from thermal expansion of seawater (around 70 centimeters per degree C) as the oceans warm and also from melting glaciers on mountains. Researchers are finally gaining an understanding of the sensitivity of the ice melt to rising temperatures and the news is not good. There is now solid evidence that a rise in sea level of a meter is very likely in the next century and this means events like Sandy will no longer be once in a century events.
Last month, I did an on air report on what just 70 cm of sea level rise will do here on Delmarva at Assateague Island National Seashore. The SLAMM model data is below and it speaks for itself. Keep in mind that a 70 cm rise is considered TOO LOW by nearly every researcher in the field.
Keep in mind that once sea level rises just 30 CM, it will only take a much weaker version of a Hurricane Sandy to cause the same damage. Sea level rise is not something that will sneak up on us, instead It will be felt all at once on, a dark stormy night when a hurricane or nor’easter hits the coast. The damage will be blamed on the storm, but the rising seas will be the hidden culprit. Just like they were in Sandy.
This is not a problem of sea level rising nor climate change but simply exhibits mans lack of wisdom and/or greed to develop infrastructure right up to present day sea level. Why would one expect infrastructure on a long shore bar last? Why build dwellings within a few hundred feet of the shore? Why build below sea level near the coast? Why build a highway on sand near the seashore? All you have to do is look around the margins of ocean or major lake basins to see remnant beaches of previous still stands in sea level to know that things change. One with any common sense at all would not build anything in this obviously hazardous zone. Maybe basic earth science should be included in everyone’s education so that they are aware that climate change cycles, sea level fluctuations, cycles in storm intensity, volcanic eruptions, earthquakes, etc. are normal in certain regions.Those who develop real estate in such geologically and climatically dangerous areas should be held accountable and have to inform potential buyers of the dangerous. I feel little sympathy for those who choose to build in such areas and then want financial assistance when a storm or landslide, etc. ruins their house on the cliff or on the beach or other infrastructure.
I consider it pure folly to continue to develop New Orleans considering the knowledge we have today considering its location. The compaction and dewatering of the deltaic sediments on which it is built will continue indefinitely taking more of the city below sea level. When one looks out of a second story hotel room and looks up to see ships on the levied Mississippi River it should make you think this is a dangerous place. When the next ‘Katrina’ or stronger hurricane strikes massive public aid will be wanted to rebuild. How many times will this be occur? As the city gradually sinks the effects will worsen. If Katrina’s effects weren’t enough to motivate the initiation of the abandonment of this city in the long term then I see a complete snubbing of the facts by planners. Obviously New Orleans needs to gradually move inland out of the danger zone. How do you do this? You select and new site having minimal dangers. This would probably be further inland and definitely at a higher topographic position. Current and future subsidence rates would need evaluation and perhaps minimized by planning for use of surface water rather than ground water.
Occupation of the new site might be encouraged via tax and other incentives and by terminating the issue of building permits within the present day New Orleans.
Similar scenarios should be initiated in other high danger areas taking into account the geologic/environmental hazards particular to each. This would allow the gradual movement people and infrastructure out of danger zones and minimize the effects of ‘natural disasters’. The methodology crudely outlined here might be a manageable way to adjust to nature’s fluctuations long term.
I agree that even without a change in sea level, it is folly to build on barrier islands. What is worse is that we all pay for the insurance of those that build there!