|Fig. 1 USGS (click to enlarge)|
On Internet sites, in newspapers, and in magazines, SLR discussions tend to be either inaccurate, unclear, and overly complicated, or a combination of all three.
It becomes more accurate, clearer, and more simplified, when our focus is sharpened by isolating the fundamental dynamics involved.
That can easily be done by:
1) knowing the SLR potentialThe first item is shown in Fig. 1 above.
2) knowing key active melt zones
3) focusing on acceleration of melt
4) knowing how much SLR is catastrophic
The second item is also shown in Fig. 1 (Greenland & Antarctica).
The third item for those two locations has been expressed by noting that from 2009 through 2013 the melt in those two locations doubled to 500 km3 yr. (according to Cryosat-2 satellite data).
Greenland's share of that acceleration was 75% of that melt (375 km3 yr.), and Antarctica's share was 25% of that melt (125 km3 yr.).
That is detailed at Will This Float Your Boat - 5.
IMO, the answer to the fourth item is: "a three foot SLR would severely damage global civilization as we know it" (The Question Is: How Much Acceleration Is Involved In Sea Level Rise?).
Thus, all we need to know is when the ongoing melt in Greenland and/or Antarctica will result in a 3 ft. global SLR (which is a function of acceleration of SLR).
Those who are crafting risk management plans have detected some problems with our ability to know when future acceleration will be catastrophic:
"As ports are operational hubs for the logistics supply chain, it is appropriate for ports to undertake an assessment in partnership with key logistics providers and /or local governments. While climate change may impact ports locally, it is often disruptions to the supply chain and local infrastructure that compound disruptions at the actual port, emphasising the need to work collaboratively on a broader climate risk and adaptation strategy [think global SLR impact].This illustrates two major problems: 1) the problem that arises when science is done for scientists, rather than for the public safety and benefit; and 2) the problem of the speed of climate change induced SLR acceleration, compared with the speed of officialdom "adapting to" any kind of appropriate change.
However, several barriers to climate adaptation have been recognised (Becker 2011, IAPH 2011, UKCIP 2007), including inconsistency between organisational planning timeframes (5 – 15 years) compared with climate projections of 30 – 90 years; as well as the uncertainty of local climate projections leading to decision-makers delaying action until there is perceived to be more certainty. To help address these concerns, this report proposes a hybrid “risk / vulnerability” approach to understanding and adapting to climate change. That is, consideration of current day vulnerabilities to extreme weather events, integrated with an assessment of future climate risks." (Climate Resilient Ports, emphasis added).
"First proposed more than 20 years ago, the Savannah Harbor Expansion Project has been studied and delayed more times over the past two decades than anyone can count. So it’s no surprise that the big news at the Georgia Ports Authority (GPA) this year has been the approval of the massive project to deepen the Savannah River and harbor to expand the Port of Savannah’s capacity.
The Savannah Harbor Expansion Project (SHEP) finally got the go-ahead in October – 15 years after it first received a congressional OK in 1999 – when the U.S. Army Corps of Engineers, the Georgia Department of Transportation and the GPA signed a Project Partnership Agreement (PPA). After years of studies, delays and lawsuits that both stalled the project and pushed projected costs sky high, construction was scheduled to begin by the end of 2014 on what has been called the most critical infrastructure development project in Georgia in decades." (Georgia Trend, emphasis added).
One does not have to be a climate scientist or oceanographer to look at contour maps in order to be able to see where SLR will show up further inland, literally moving coasts and boundaries around the world:
"Sliced by population rather than city, and looking at today rather than the future, the report found that about 10 percent of the affected cities’ populations, or a total of about 40 million people, and $3 trillion of property, are already susceptible to these devastating, once-in-a-century floods (and of that $3 trillion, 60 percent is found in just three countries: the U.S., Japan, and the Netherlands). By 2070, says the report, the combined effects of population growth, migration to cities, and rising seas will boost those numbers to 120 million people and $35 trillion.”(SLR for 20 Global Ports, emphasis added; cf. SLR @ Coastal Cities). The difficulty comes with trying to determine when SLR becomes catastrophic to world civilization (What Do You Mean - World Civilization?, 2).
Scientific groups, for some time now, have realized that "determinations of when" have been consistently underestimated and/or overlooked:
Changes in the area and volume of the two polar ice sheets in Antarctica ... and Greenland are intricately linked to changes in global climate, and could result in sea-level changes that could severely affect the densely populated coastal regions on Earth. Melting of the West Antarctica part of the Antarctic ice sheet alone could cause a sea-level rise of approximately 6 meters (m). The potential sea-level rise after melting of the entire Antarctic ice sheet is estimated to be about 73 m. In spite of its importance, the mass balance (the net volumetric gain or loss) of the Antarctic ice sheet is poorly known; it is not known whether the ice sheet is growing or shrinking. As a result, measurement of changes in the Antarctic ice sheet has been given a very high priority in recommendations by the Polar Research Board of the National Research Council, by the Scientific Committee on Antarctic Research (SCAR), and by the National Science Foundation’s Office of Polar Programs.(USGS 2005, emphasis added). Therefore, they are leaning toward changing that defect.
What was "poorly known," as recently as ten years ago, is now becoming known to "a more reasonable degree" (as pointed out by the earlier discussion of Cryosat-2 data).
What we see, then, is that civilization had spent untold trillions in order to make endless war, go to the moon, asteroids, comets, and other planets, but we had not all arrived on Earth yet (You Are Here).
We did not know about the great danger of Antarctic ice melt, which would bring down current civilization (240.53 ft. of SLR, see Fig. 1).
As a result, we do not know exactly when we will destroy our civilization, or ourselves (Civilization Is Now On Suicide Watch, 2, 3, 4, 5, 6, 7, 8).
Nevertheless, it is becoming much more clear, day by day, that we are failing The Test (The Tenets of Ecocosmology).
Oscillation in Greenland melt rates:
|Credit: National Snow and Ice Data Center|