Guest Post by Willis Eschenbach
Science Magazine is published by the American Association for the Advancement of Science. I’m reading my AAAS Newsletter, and I find the following blurb (emphasis mine):
Virginia Panel Releases Coastal Flooding Report. A subpanel of the Secure Commonwealth Panel of Virginia released a report containing several recommendations for dealing with risks posed by coastal flooding. The report, which is largely based on data from a 2013 report by the Virginia Institute of Marine Science, predicts a sea level rise of 1.5 feet within the next 20 to 50 years along the Virginia coast.
My bad number detector started ringing like crazy. Let me convert that to metric and see where we get. A foot and a half is 450 mm. Global sea level rise these days is on the order of two to three mm per year. This is also about the rate of rise that has occurred over the last century. To rise a foot and a half at the historical (and current) rate would take from 150 to 225 years. OK, we’ll need to shorten that for local subsidence, but still … so I go to take a look at the underlying report I linked to above.
I get the report, and I’m reading through it, and I bust out laughing. There’s been a recent thread here on Watts Up With That regarding consensus. I thought that this was a marvelous example of the modern and meaningless use of the term “consensus” (emphasis mine).
The future of sea level change in Virginia is most appropriately forecast by reference to the state-of-the-science synthesis and recommendations prepared for the National Climate Assessment (Parris et al. 2012). The consensus of scientists working on this report is that by 2100 global sea level will be between 8 inches and 6.6 feet above the level in 1992. When modified by local and regional factors this information provides the best available basis for planning. SOURCE
The “consensus” is that sea level rise by 2100 will be between eight inches (20 cm) and seven feet (2.1 m)? Oh, that’s just too good. And how is that floor-to-ceiling estimate the “best available basis for planning”?
In any case, the report allows us to run the numbers. According to the report, they have allowed 2.7 mm/year for local subsidence, viz:
Therefore the future sea level scenarios presented in Figure 16 are the global scenarios modified to include local subsidence (estimated at 2.7 millimeters/year or about 0.1 inch/year).
To get that 450 mm (1.5′) of rise in 50 years would require that the seas rise by no less than nine mm per year. If we allow 2.7 mm/year for subsidence as they did, it would have to rise at 6.3 mm per year, starting now and continuing for fifty years.
And it gets worse. To get that foot and a half of rise in 20 years would require that the seas immediately start rising at 22.5 mm per year, call it 20 mm per year after subsidence. I note in passing that this rate is the maximum rate mentioned in the underlying document … in other words, they’ve taken the absolute worst and most ludicrous estimate, 6.6 feet by the year 2100, and called that the “best available estimate for planning”? … spare me …
And how fast is the sea level rising around Virginia, including subsidence? There’s a curious side story. I google subsidence Virginia tide. First link returned? “Making sense of senseless sea level scares in Norfolk Virginia“, right here at WUWT. Goes to show the global reach of this blog, you don’t get to the top of the Google food chain unless lots of folks link to your post …
In any case, that post shows the trend of sea-level rise at Sewells Point VA is 4.4 mm/yr and 3.8 mm/yr at Portsmouth, Virginia. IF the subsidence is in fact 2.7 mm/year, this puts the Sewells Point sea level rise without subsidence at 4.4 – 2.7 = 1.7 mm/year … and at Portsmouth, 3.8 – 2.7 = 1.1 mm/year rise excluding subsidence.
So it looks like in Virginia, IF we make their assumption of 2.7 mm/yr of subsidence, the sea level itself is historically going up at no more than two mm per year … and they claim it’s going to jump immediately to three to ten times the historical rate? Fuggedaboutit.
Here’s the crazy part. In parallel with the current “hiatus” in warming, we have seen a deceleration in the rate of sea-level rise. I discussed an attempt to explain this “pause” in sea-level rise in my post “Sea Water Level, Fresh Water Tilted“. Anthony also discussed this slowdown here.
Now, the alarmists started this booshwa about an impending and dangerous acceleration in sea-level rise back in the 1980s. James Hansen has repeated this claim of impending acceleration for decades, as have many others. It’s become a recurrent meme for the alarmists, repeated around the world. And for all of that time, there hasn’t been the slightest sign of any increase in the rate of sea-level rise. None at all, and indeed, instead of acceleration, we’ve seen deceleration.
However, when it comes to climate alarmism, facts don’t seem to be important in the slightest … welcome to post-normal science, where actual observations and real-world data are just an insignificant detail.
PS—the usual request. If you disagree with someone, please quote the exact words you disagree with. Otherwise, nobody knows what you are referring to, and misunderstandings multiply.