sealevelinfo | Indy Week

Member since Nov 15, 2013

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Re: “John Rhodes: The guy with nine U.S. Senate votes

John Rhodes doesn't like Tillis, but he loves his country, so he probably held his nose and voted for Tillis (really, against Hagan).

2 likes, 5 dislikes
Posted by sealevelinfo on 11/06/2014 at 3:16 PM

Re: “N.C. Museum of Natural Sciences director puts kibosh on documentary about sea-level rise

No, Denis, you are mistaken. Quoting from the third paragraph of that paper:

"To reconcile the nearly factor of 2 difference in the tide gauge and altimeter global rates, reconstructions of global sea level from tide gauges have been made using empirical orthogonal functions (EOFs) obtained from satellite altimeter data...

Do you see the 3rd to last word? It is "satellite."

You say that there's no difference between the tide gauge measurements and the satellite numbers. But the paper says that there's "nearly a factor of 2 difference."

If you just look at tide gauge data, there's been no acceleration in over 80 years, unless you constrain your examination to specific regions, where well-known oscillation patterns cause alternating periods of apparent acceleration and deceleration (like Sallenger did).

2 likes, 2 dislikes
Posted by sealevelinfo on 11/20/2013 at 3:16 PM

Re: “N.C. Museum of Natural Sciences director puts kibosh on documentary about sea-level rise

P.S. - Benjamin, regarding the links that you suggested for the site:

1. There's long been a link to the U. Colorado material on the "Resources" page of the web site, along with a link to an article & discussion that will help you understand it.

2. You accidentally omitted the link to this paper, but I googled the title and found it:
It's paywalled (if you have a copy please send it to me). But the abstract indicates that the article provides more evidence that anthropogenic GHGs have NOT caused increased sea level rise increase. (Based on NC salt-marsh "proxies," the authors conclude that the rate of sea level rise in NC last increased prior to 1915.)

2 likes, 1 dislike
Posted by sealevelinfo on 11/20/2013 at 7:32 AM

Re: “N.C. Museum of Natural Sciences director puts kibosh on documentary about sea-level rise

Benjamin, you say I "[refuse] to acknowledge the validity of sea level rise data from the past twenty years [which] clearly demonstrates your agenda." But I'm not the one who's ignoring the data. That's you.

For instance, you link to a graph just Topex/Poseidon, Jason-2, and just half of the Jason-1 satellite data. Why do you suppose that graph omits ERS2, Envisat, and the rest of the Jason-1 data?

The answer to that question is pretty obvious when you look at what it shows. We have 20 years of satellite altimetry data for sea-level in the open ocean. It is of dubious quality, but, for what it is worth, it shows a clear decrease in the rate of sea-level rise over that period. Here's a graph, with all six satellites shown:
Note that Aviso graphs the Envisat data in light yellow, and starts it way above the baseline, to obfuscate the fact that it measured much lower SLR than the earlier Tpoex/Poseidon & ERS2 satellites did. Even so, the deceleration is obvious.

We also have over a century of tide-gauge data, from many reliable gauges, measuring coastal sea-levels. They also show that there's been no increase in the rate of sea-level rise in the last 80 years. In fact, the most careful and thorough studies of tide gauge data show a slight DECREASE in the rate of sea-level rise (though that slight decrease might be due to cyclical factors).

Only by conflating measurements from different locations is it possible to create the ILLUSION of accelerated sea-level rise.

Why is this hard for some people to understand?

Contrary to what you wrote, I do not deny that retreating glaciers, and probably Greenland, are contributing meltwater that is raising the oceans. (Studies of ICESat and GRACE measurements differ in whether Antarctica is contributing meltwater.) But the rate of that rise is not increasing.

Globally averaged coastal sea-levels are rising more than 1 mm/year, despite a calculated post-glacial sinking of the ocean floor that Peltier estimates should cause about 0.3 mm/yr decline in sea-level. If Peltier's estimate is right, and actual average coastal sea-level change plus the Peltier adjustment come to about 1.5 mm/yr, that's equivalent to over 140 cubic miles(!!!) of melted ice! Even if some of the water is coming from groundwater depletion, or other factors, it is still a LOT of melted ice, probably more than 100 cubic miles of it.

But that's not the issue. The question is what effect have humanity's CO2 (and CH4) emissions had? And the answer is "none that we can detect."

That rate of ice melt clearly has not increased in more than 80 years. The oceans are rising no faster now than they were 80+ years ago. Yet the great preponderance of anthropogenic GHG emissions have occurred since the 1940s. That means there's no evidence in the sea-level measurements that anthropogenic GHG emissions have increased the rate of sea-level rise at all.

Do you deny that fact, Benjamin?

I also ask that you not make up "straw men" that I've never said. You referred to, "the 'mysterious' stop in sea level rise you like to talk about." But I never mentioned any "stop" in sea level rise. You just made that up.

As for the site, to see the spreadsheets with NOAA's tide gauge analyses, click on the "data" link at the top of the main page, then view any of the spreadsheets.

NC has only one GLOSS Long Term Tide gauge. It's the Wilmington gauge. Over it's 78.5 year history, sea-level rise averaged 2.0 mm/year (of which Peltier estimates that 0.88 mm/year is due to local subsidence), with no sign of acceleration. (In fact, sea level hasn't risen at all at Wilmington in the last 20 years, presumably due to cyclical factors.) Click on the station name ("Wilmington, NC, USA") to view the graph.

Over the last 78.5 years, the rate of sea-level rise at Wilmington has averaged only 2 mm/yr, with no sign of acceleration. Extrapolating that for the next 87 years adds up to less than 7 inches by 2100. That's hardly "rising precipitously."

2 likes, 1 dislike
Posted by sealevelinfo on 11/19/2013 at 11:36 PM

Re: “N.C. Museum of Natural Sciences director puts kibosh on documentary about sea-level rise

Denis, you're comparing apples with oranges. (It is a common mistake.)

The pre-1993 sea level rise number that you quote is averaged tide gauge measurements of coastal sea levels (adjusted by very rough model-derived PGR calculations). The post-1993 number that you quote is for sea level rise in the open ocean measured by satellite altimetry. (Note that satellites cannot measure sea level at the coasts.)

Sea level change varies widely from one location to another, for a variety of reasons. At about 3/4 of the GLOSS-LTT tide gauges, sea level is rising, and at about 1/4 of those gauges it is falling. On average, sea level is rising very slowly, but few locations are "average."

So if you measure sea level at two different locations, you'll generally get two different numbers, even if you use the same measurement techniques. I've found that if long-term tide gauges are not closer than 500 miles apart, their sea-level measurements are no better correlated than are measurements taken halfway around the world.

The 1.7 mm/yr and 3.2 mm/yr numbers that you quoted are different quantities, measured by different methods, at different locations. It would be quite a coincidence if the numbers were the same.

Sea level rise measured by coastal tide gauges has shown no increase (acceleration) in over 80 years. Here are some relevant papers:

Sea level rise in the open ocean measured by satellite altimetry also has shown no increase (acceleration) over the 20 year measurement record. (It's actually shown noticeable deceleration, but in my opinion twenty years is too short of a record to draw definite conclusions from that.)

Only by conflating measurements taken at different locations is it possible to create the illusion of accelerated sea level rise in the last 80 years. This google search will find some relevant discussions:

Additionally, the tide gauge (coastal) measurements are (mostly) quite reliable and precise, and the satellite measurements are not. You may learn about the technical problems which make sea level measurement by satellite altimetry unreliable here (starting at 17:37):

Hmmmm... I see that some of the comments here have clickable links, but I can't seem to make that work. Do you know how to make the links work?

3 likes, 4 dislikes
Posted by sealevelinfo on 11/18/2013 at 10:48 AM

Re: “N.C. Museum of Natural Sciences director puts kibosh on documentary about sea-level rise

The theatrical trailer of "Shored Up" is just 2.5 minutes long, but I counted five (5) blatant falsehoods, plus a couple of more subtle deceptions. I doubt that the whole film keeps up with that impressive rate of one lie every 30 seconds, but it certainly is not by any stretch of the imagination "objective and well-rounded."

0 likes, 4 dislikes
Posted by sealevelinfo on 11/18/2013 at 4:53 AM

Re: “N.C. Museum of Natural Sciences director puts kibosh on documentary about sea-level rise

Leslie Gura, here are the two most important facts that you need to know:

1. Over the last 3/4 century average outdoor atmospheric CO2 levels have increased by about 100 ppm, from ~300 ppm to ~400 ppm. (That period accounts for nearly all of the anthropogenic increase in atmospheric CO2 in human history.)

2. We have excellent, reliable, long-term sea-level measurements from hundreds of locations, many of them with continuous or near-continuous readings extending back more than a century. The best of those sea-level measurements and the most comprehensive studies of those measurements show that there has been no measurable acceleration in the globally averaged rate of sea level rise in over 80 years.

In other words, that 100 ppm increase in atmospheric CO2 levels has not, thus far, resulted in ANY detectable increase in the rate of coastal sea level rise.

Albert Einstein supposedly defined insanity as doing the same thing repeatedly and expecting different results. We've done the experiment once, and we know the result. Adding 100 ppm of CO2 to the atmosphere has not caused any detectable increase in the rate of sea level rise. It would be very surprising if repeating the experiment were to result in a substantially different outcome.

Predictions that elevated atmospheric CO2 levels will result in wildly accelerated sea-level rise are unscientific nonsense, driven by political and pecuniary interests, rather than sound science. But some activists wanted such predictions to guide coastal planning and regulations.

Contrary to what this article claims, the purpose of HB-819 was to ensure that coastal policies are guided by sound geophysical science, rather than political science. Most NC legislators agreed with that goal. In the Senate, there was only one "no" vote, and Democratic Governor Perdue did not veto it.

What do you think is "ridiculous" about that? Please quote the specific provision(s) of the bill that you think are ridiculous.

3 likes, 5 dislikes
Posted by sealevelinfo on 11/17/2013 at 7:24 AM

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