Bob Tisdale sez "I knew that", 'cept he didn't!

You've probably come across the sort of person who when asked a question gives the wrong answer. Then when told the correct answer will squirm and sulk and say "I knew that". They get scornful looks but it doesn't seem to faze them.

Bob Tisdale is behaving like that today (archived here). He is writing about what he regards as "An Unexpected Admission from Dana Nuccitelli at SkepticalScience". What did Bob not expect? He didn't expect Dana to explain how El Niños lift average surface temperature and La Niñas suppress it. Though he did twist Dana's words. Bob wrote:

Dana admitted that during a decade-long (or multidecadal) period(s) when El Niño events dominate (when El Niños are stronger, last longer and happen more frequently), the El Niños enhance global warming, and during periods when La Niña events dominate (when there are weaker, shorter and fewer El Niño events), the absence of El Niño events suppresses the warming of global surfaces.

Note the use of the word "admitted". Bob has been getting tips from David Rose on the abuse of rhetoric. Bob twisted what Dana wrote a bit. Fortunately he then quoted him directly. There was only one paragraph on ENSO and this is what Dana wrote (from the Guardian):

...average global surface temperatures have warmed between 0.6 and 0.7°C over the past 40 years (lower atmospheric temperatures have also likely warmed more than 0.5°C, though the record hasn’t yet existed for 40 years). During that time, that temperature rise has temporarily both slowed down (during the 2000s, when there was a preponderance of La Niña events) and sped up (during the 1990s, when there was a preponderance of El Niño events). Climate models accurately predicted the long-term global warming trend.

Do you spot the difference? Bob was saying it was the absence of El Niños, whereas Dana was writing it was the preponderance of La Niñas, when surface temperatures didn't rise as quickly were suppressed. That's not splitting hairs. Bob Tisdale wrongly thinks that El Niños cause global warming, which is why he talks about it in that way.


Bob is also trying to claim that fake sceptics discovered this about ENSO. How ludicrous is that. Heck, Bob won't usually even admit that ENSO doesn't have a long term effect - it comes and goes.  ENSO events can temporarily boost or suppress the relentless upward trend in global surface temperature. They aren't what is causing global warming. That's down to the greenhouse effect - from increasing CO2.

As for his surprise at Dana's article - surely he's seen the escalator. I know he has seen this older article by Dana, which has the graphic shown below. He wrote about it at the time - only that time he disagreed with what Dana wrote (though it was much the same thing). So Bob already knows that Dana understands much more about ENSO than he, Bob, does. Dana's chart demonstrates how ENSO events affect global surface temperatures:

Source: SkepticalScience

Bob Tisdale's rare admission

It's not surprising that he feigns surprise about something he already knew (that Dana Nuccitelli knows about ENSO.) What is surprising about Bob Tisdale's article is this that was buried within:

The standard argument now from the CO2 obsessed is that over multidecadal time periods the natural enhancements and suppressions of global warming will cancel out because ENSO and the AMO are oscillations. 

I've never seen Bob write anything like that before. I'm not suggesting he subscribes to the notion that oscillations don't have a long term impact on temperature, but to even acknowledge the fact of oscillations is a breakthrough. I've never before read Bob giving any indication that he understands what an oscillation means. I might have missed it, I suppose.

ENSO has always puzzled Bob in that way. Maybe some climate science is finally sinking in. Though not much is. He wrote:

El Niños didn’t only dominate during the 1990s. For some reason known only to Dana, he overlooked the fact that the 1976/77 El Niño started the period when El Niño events dominated the late 20th Century. Thus, using Dana’s logic, El Niño events enhanced the observed global warming from the mid-1970s to the turn of the century—the first 25 years of the past 40 years Dana chose for his discussion.

ENSO and the PDO and global surface temperature

Here is a chart showing the different ENSO years, on which I've overlayed the phases of the PDO (from Nate Mantua's website). You can click on the chart to enlarge it.

Data sources: GISS and Nate Mantua and BoM

During a warm PDO phase, El Niño events tend to exacerbate global surface temperatures more and the impact of La Niña is not as great. During a cool phase, La Niña events tend to be exaggerated and the effect of El Niños on global surface temperatures are not as great. I cannot find anywhere that states categorically what phase we are currently in. As the above chart shows, there was almost an equal number of years in both phases of ENSO. The PDO index gives a guide. Below is a plot of GISTemp against the PDO index:

Data sources: GISS and Nate Mantua

If we have been in a shortish cool phase and are now emerging into a warm phase, then global surface temperatures will probably go up even more quickly over the next few years.

Bob's words are contradicted by his own chart

Bob then wrote something odd. He said:

Climate models don’t consider the ENSO-enhanced portion of the global warming from the mid-1970s to the turn of the century.  See Figure 1, which compares observed global surface temperature anomalies for the past 40 years to the model simulations of global surface temperatures. 

But Bob's chart belies his words. His Figure 1 shows extremely close congruency between the model mean and the global surface temperature from the mid-1970s.  You could hardly ask for better. Right up until the forcings plugged into the models could not be based on observations (from 2006), the model mean is remarkably close to observations.

Source: WUWT

Someone tell Bob Tisdale what "long-term" means

There is just one more thing that I'll mention. Bob doesn't understand a lot of things, but he doesn't understand the meaning of the word "long-term". He wrote:

There is, of course, a major problem with Dana’s last sentence in that quote:
“Climate models accurately predicted the long-term global warming trend."Climate models don’t consider the ENSO-enhanced portion of the global warming from the mid-1970s to the turn of the century. 

Bob skips over the word "long-term". In any case, for not considering whatever, the models have done a remarkable job of emulating global surface temperature from the mid 1970s to the turn of the century, haven't they! Bob's very own chart shows that.

Bob thinks climate models are weather forecasts

Bob keeps confusing climate models with weather forecasts. He looks at ENSO and thinks "climate". But ENSO is at best an interannual feature. Single ENSO events don't persist on the scale of climate (multiple decades).  (Phases of the PDO tend to last for multiple decades, but they too oscillate and don't have a permanent impact on long term temperature trends.)

Climate models don't and probably never will emulate ENSO events at the same time as they occur. What they do is model climate, not weather. In regard to temperature etc it's the long term trend that they focus on - on the scale of multiple decades.  Models do exhibit internal variability as well as the result of external forcing. However that won't necessarily be in phase with what actually happens. They've been remarkably good at doing what they were designed to do - model climate trends. Climate can be described as the limits of weather - the upper and lower boundaries expected. It's not about whether an El Nino occurs this year or next year. Bob is just another dumb denier - he doesn't understand the difference.

Gotta go. If you want to read the comments or the rest of Bob's article, click here.

From the WUWT comments

I just noticed this exchange, so figured I'd post it. Bob Tisdale is blind as a bat, or nuts, if he can't see the long term warming trend. Barry posted a chart showing the ENSO years, and wrote a non-controversial comment:

January 24, 2015 at 9:24 am
Actually it’s both linear and cyclical — climatic variations imposed on a warming trend.

To which Bob Tisdale let his denial slip and replied:

January 24, 2015 at 1:00 pm
Barry, are you purposely contradicting Nuccitelli now?

Also, the vast majority of the people who visit here understand “climatic variations imposed on a warming trend” is incorrect. In reality, ENSO has caused a major portion of the surface warming during the satellite era of sea surface temperature data. In fact, in the post, I linked a detailed description of how that works. Here it is again: 

For one thing, Barry didn't contradict Dana. Bob can't or won't understand what Dana wrote, with the emphasis on won't. For another thing, Bob ignores all the La Nina years and weirdly thinks that the oceans just keep getting hotter and hotter by magic. His "chaotic, naturally occurring, sunlight-fueled, recharge-discharge oscillator".

Poor old Bob is like a broken record of the Dunning Kruger kind. He insists upon this, even though (a) the incoming solar radiation has declined a bit and (b) since 1999 there have been more La Nina years (5) than El Nino years (4)! If not for greenhouse warming, then the surface temperature would be much lower. Bob clearly doesn't understand the meaning of the words "oscillation" or "cycle". On the other hand, Bob is probably correct when he writes about what some of the deniers at WUWT understand - although what they understand is wrong and much more varied than what Bob Tisdale would have you believe.

[Added a bit later by Sou.]