Dr. Trenberth Redux

Guest Post by Willis Eschenbach

A couple days ago, I was given a copy of a most interesting interchange from 2011 between Dr. Kevin Trenberth and a layman asking him a question. The sender of the question recently passed it on to me. I’ve redacted the email addresses and the name of the person asking the question, but otherwise it is totally unaltered.

From: “Kevin Trenberth” <trenbert@XXXXX.edu>

To: “Dr XXXX” <xxx@xxx.xxx>

Sent: January XX, 2011 X:XX PM

Subject: Re: warming

Dear Kevin,  

Thank you for your prompt reply. I’m 62 and now semi-retired. I’d like to  bring myself up to speed on global warming, which I read is one of the great catastrophes of our time. You describe rising sea levels as being the evidence for man caused global warming. It had been my understanding that sea levels have been rising steadily for thousands of years and now at a very slow rate. I know there’s been a huge increase in man’s CO2 in the heavy industrialisation since World War 2. How has this increase in man’s CO2 effected sea levels ? 

The rates have not been steady and picked up markedly in the mid 20th century and even more since 1990 or so. CO2 has been increasing since 1750 although mainly since 1850.

That was Dr. Trenberth’s entire reply to the question.

Now, I found this interchange quite amazing. Here’s somebody asking for information, and Dr. Trenberth’s response about sea levels is … well … almost fact free.

First, he says that “the rates have not been steady and picked up markedly in the mid 20th century” … there are a couple of well-cited analyses of this question. One is by Jevrejeva et al., and the other by Church and White. Here’s what Jevrejeva et al. said about the rate of change of the global sea level (gsl)

Figure 1. Jevrejeva analysis of global sea level (“gsl”, upper panel), and rate of change of global sea level (“gsl rise, lower panel). Source

As you can see, the idea that the rate of sea level rise “picked up markedly in the mid 20th century” is totally contradicted by the Jevrejeva data.

How about Church and White (C/W)? Here’s their analysis of the situation:

 Figure 2. C/W analysis of rate of change of global sea level. Source 

Again there is little evidence that the rise “picked up markedly in the mid 20th century”. Instead, it continued to go up and down, even as far as zero.

How about the claim that in the 1990s there has been “even more” rise? Well, there’s nothing like that in the Jevrejeva data, but there is in the C/W data. I suspect that that’s what Trenberth is referring to. Why is there such a jump in the C/W analysis?

It’s because Church and White played fast and loose. They simply spliced the satellite-based sea level data onto the tidal stations data, ignoring the fact that the satellite rise is about 50% higher than the tidal station data.  So they just hoisted up the tidal data by that amount, so it would kinda sorta match to the satellite data … and then smoothed the splice with a centered filter. Bad scientists … no cookies.

So yeah, when you go past the splice the rate of rise SEEMS to go up from about 2 mm/yr to 3 mm/yr … which is what Trenberth has reported as fact. But it’s not a fact at all, it’s just a splice.

But wait, it gets worse. In fact, far from increasing as Trenberth claimed, the satellite-measured sea level rise has actually been decreasing, as shown by Cazenave et al. …

 Figure 3. ORIGINAL CAPTION: GMSL [global mean sea level] rate over five-year-long moving windows. a, Temporal evolution of the GMSL rate computed over five-year-long moving windows shifted by one year (start date: 1994). Source (paywalled)

I discussed the Cazenave et al. results shown in Figure 3 in a post called Sea Water Level, Fresh Water Tilted. Now Dr. Cazenave’s study was published in 2014, so Trenberth wouldn’t have known of that in 2011. However, I noted the decrease in the satellite data back in 2010  here, so it’s been visible in the raw data for some time. Here’s my graphic from that post:

Figure 4. Variations in the sea level as measured by the TOPEX/JASON satellites.

Since he’s setting himself up to answer questions about sea level, Dr. Trenberth certainly should have known of the decrease.

Here’s my point in all of this. A variety of people, even good honest scientists like Dr. Judith Curry, have been publishing a host of posts and studies claiming that the problem with climate science has something to do with bad communication. Dozens of theories have been advanced to try to explain why Americans are totally unconvinced by climate scientists, why we consistently rank climate as the least of our problems. Why, they ask, are climate scientists unable to get their message across to the American public?

These theories are all about how scientists are not explaining things in the right way, or about how “deniers” have a different mental makeup than the faithful, or how there is a lack of clarity in what the scientists are saying, or how the framing of the message was incorrect … but in nearly every case, the issue is cast as being one of poor communications.

(Let me say in passing that given that the climate alarmists have had the full and enthusiastic backing for several decades of the mainstream media, and of the governments, and of the schools and universities, and of the leaders of various professional societies, and of the jet-setting Hollywood stars, and have been funded to the tune of millions and millions of dollars to try to get their message across, including $300 million from Al Gore, and $74 million from Tom Steyer, and have had lots of advice from expensive media and communications consultants … well, after three decades of that immense pressure, “poor communications” seems the least likely explanation for their failure. But I digress.)

However, this exchange puts the lie to all of that. There is no lack of clarity in Trenberth’s statement that

The rates have not been steady and picked up markedly in the mid 20th century and even more since 1990 or so. 

There’s no communication problem there, no murkiness, no poor framing. The problem is that Trenberth is spouting the same old alarmist nonsense about “accelerating sea level rise”, a claim that is demonstrably untrue. Sea level rise hasn’t accelerated. To the contrary, it has slowed down.

I don’t know why Trenberth made those crazy claims, whether he was honestly mistaken, or he knows but doesn’t care, or he actually doesn’t know what the sea level is doing, or he is just pushing an agenda. Be clear that I make no claims about his motives, his knowledge, or his mental state. I truly don’t know why he answered the way he did.

But what I do know is that after decades of being spoon-fed bovine waste products by climate scientists, who the whole while have been confidently assuring us that it’s ice cream … the American public has wised up.

It reminds me of the joke you’ve likely heard …

A kid says to his friend, “What’s that in your hand?”

His friend says “They’re smart pills! They make you smarter. You want one?”

“Sure”, says the kid, and he eats one and makes a terrible face. “These aren’t smart pills,” the kid says, “these are sheep droppings!”

“See?” his friend says. “You’re getting smarter already!”

So yes … thanks to repeated doses of Dr. Trenberth’s Smart Pills being prescribed by far too many climate scientists, the American people are getting smarter already.

My best to all,

w.

De Costumbre: If you disagree with what someone says, please QUOTE THE EXACT WORDS THAT YOU DISAGREE WITH. That way we can all be clear about exactly what you think is incorrect.