WUWT has stepped up their ongoing campaign to downplay the threat of sea level rise. This includes a recent post by Larry Hamblin which indulges in a just-plain-wrong method for pushing the the “no acceleration” meme, and a post by someone calling himself “Giordano Bruno” which disputes the increased sea level rise in the northeast U.S. “hotspot” based on — put your coffee down, please — the “trend” over a whopping five whole years.
What most strikes me about the “Bruno” post is that the terminology is far too reminiscent of Albert “Making Up Stuff” Parker. He’s the fellow who sometimes goes by the name Albert Parker, sometimes Alberto Boretti, and once even submitted two comments on the same paper to a peer-reviewed journal, one under each name. Perhaps now he isn’t satisfied with either name, instead fashioning himself after the famous Italian. Is the post really from Alberto-Giordano Bruno-Boretti-Parker?
The “Bruno” post makes trend pronouncements based on a ridiculous, silly, yea ludicrous short span of time. Yes, a mere 5 years and four months. It would be hilarious if it weren’t so pathetic one is tempted to take pity on Bruno-Boretti. Here’s his illustration for the tide gauge data from the Battery in New York:
The section at the end is his basis for claiming that sea level is now falling. Of course that ignores over 95% of the data … nothing to worry about at all. It reminds me of a similar attempt which ended in embarrassment for Bjorn Lomborg (image courtesy of Greg Laden):
The “Bruno-Lomborg” strategy has become the mainstay of those who deny the reality, human cause, or danger of climate change: find some short time span somewhere — anything, anywhere, no matter how brief — during which the never-ending fluctuations of data mask the underlying trend, then declare those fluctuations to be the trend. Perhaps the fact that their chosen time spans are so embarrassingly short, doesn’t matter to them any more than actual facts matter to Donald Trump.
But when it comes to sea level rise, what are the WUWT boys to do? They can’t deny that sea level is rising (even they aren’t that stupid — maybe), and they can’t deny that the people of south Florida (voters, even) are extremely worried about it (as are a lot of people) and are spending a lot of money to deal with it.
Larry Hamblin retreats to the “no acceleration of sea level rise” meme. Here’s the gist of his argument:
Additionally NOAA performs 95% confidence interval analysis of each location to determine if there are significant changes in the tide gauge measurement trends over time.
The 95% confidence interval analysis demonstrates that the linear sea level rise trend is stable and unchanging.
That’s wrong. Maybe it’s “not even wrong.”
Comparing the trend from 1856 to 2006, to that from 1856 to 2015 isn’t going to reveal whether there’s been any acceleration (i.e., a change of the slope of the long-term pattern). Those two time intervals are practically guaranteed to show the same linear trend because they’re based on almost the same data!
Allow me to illustrate. I generated some artificial data with a negative slope from 1895 to 1990 and a positive slope from 1990 to 2015, plus random noise. It looks like this:
The slope change isn’t easy to see, but it’s ridiculously easy to detect and confirm statistically. You could fit a quadratic, or a piecewise linear model, and either would confirm a slope change without doubt.
But if we compute trends from 1895 through 2006, then through 2007, etc., all the way up to “through 2015,” all those calculations shared most of their data in common so we expect them to show similar linear trends in spite of the easily-confirmed change. And indeed they do:
Certainly their “95% confidence intervals overlap.” By a lot.
If you really want to know whether there’s been a slope change in sea level along the U.S. coast, stay tuned here for a post on that very topic soon because there actually are decent methods to look for it. But don’t rely on posts at WUWT; they aren’t likely to accidentally wander into “valid analysis” country any time soon (or should I say “ever”?).
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