Bob Tisdale tries to hide the massive warming

How do you get rid of warming that you want to deny? That's easy. You just subtract it from the record and ignore it.

Bob Tisdale is a pseudo-scientist at WUWT who doesn't believe that CO2 is warming the planet. He's a greenhouse effect denier. His notion is that El Ninos are what's warming the Earth by magic, or what he calls "sunlight-created warm water". I didn't know that sunlight created water, but who am I to say?

In a new article (archived here), Bob is trying to persuade the climate conspiracy theorists that the big spike in the global mean surface temperature was just what he expected. That's despite his numerous articles where he tried to show this El Nino isn't as big as the 97/98 one. And despite the fact that it's way hotter now than it was in the late 1990s. Bob weirdly thinks that the recent rise in global surface temperature has nothing to do with the increase in greenhouse gases.

Bob is wanting to divert attention from the unrelenting rise in global surface temperature.  The linear rate of warming since the mid 1970s is around 0.17 °C each decade. Bob Tisdale doesn't want his readers to notice that, so what he did was subtract 0.42 °C from the 2015/16 monthly temperatures and superimposed the plot on a chart of 1997/98 global monthly temperatures. He was trying to make the last 18 years of global warming disappear. In fact he over-reached, as I'll show you.

Is it little green men from Mars, a blob, or ENSO?

Bob wrote an article and posted it at WUWT under the headline:

More Alarmist Nonsense with the Release of the Redundant* NOAA Global Temperature Data for February 2016

I don't know if Bob knows the meaning of the word "redundant". It doesn't make any sense in his headline. His asterisk goes to this, without any explanation of why he thinks that the temperature record is redundant:

Or Maybe the GISS Land-Ocean Temperature Index is Redundant

His fans don't need any persuading that global warming is nonsense. If he told them that little green men from Mars were causing global warming they'd barely react. Deniers are happy as long as it's anything but CO2 and anything but human activity. Better still would be him telling them it's not warming. Well Bob Tisdale has also tried that on by accusing NOAA scientists of fraud and fudgery. He still uses the data they've provided though.

How the world has warmed

Before looking at what Bob Tisdale did, here are some charts showing how the world has warmed, and the extraordinary month of February 2016. First a chart of the Northern Hemisphere monthly temperatures, The northern hemisphere is where most of the extra warming took place last month:

Figure 1 | Monthly global mean surface temperature anomalies from January 1880 to February 2016. Data source: GISS NASA

That is extraordinary even for an El Nino year. Here is a map showing the hot spots. You can see that it's mostly in the high latitudes of the northern hemisphere. Some, but by no means all, would have been heat coming up from the tropical Pacific:

Figure 2 | Map of temperature anomalies February 2016. Source: GISS NASA

Next a chart of global mean surface temperature, showing February 2016 in comparison with February in the second year of two recent El Ninos:

Figure 3 | Monthly global mean surface temperature anomalies from January 1997 to February 2016. Data source: GISS NASA

Again, the chart looks quite extraordinary. Looks can be deceiving. However, as Tamino showed, even when removing the effect of ENSO, volcanic and solar forcing, leaving mainly greenhouse forcing and other internal variability, February was hot. The long term trend is also clearly visible:

Figure 5 | Global surface temperature anomalies with volcanic and solar forcings removed as well as ENSO variability. Credit: Tamino

Bob Tisdale's diversion

Bob Tisdale put up a chart showing the big spike in global mean surface temperature last month. None of his fans took much notice of that, and neither did Bob. It's what he did next that will or won't surprise you. Bob made the warming disappear by subtracting 0.42 °C from the 2015-16 data. What he was trying to argue was that the warming since January 2015 was to be expected because of El Nino. In fact that's only part of the story. Some of the warming was in regions other than the tropical Pacific as the map above illustrates.

However let's accept that in an El Nino year, a spike in the global mean surface temperature is expected. No-one can argue with that. Where Bob gets it wrong is that he seems to be trying to argue that the temperature spike would have been as high without greenhouse warming. It's the fact of an unsurpassed record and the huge jump in monthly temperature anomalies that has got people talking.

What caused the 0.42 °C difference?

Bob missed the point completely. Of course scientists and anyone who knows anything about climate know that El Nino increases the global mean surface temperature, all else being equal. What Bob refuses to acknowledge is that the temperature increase from this El Nino is on top of a long term warming trend.

What Bob did was take the average of January, February and March for 1997 and set it as the zero baseline for 1997/98 temperatures. He then took the average of January, February and March 2015 and set it as the zero baseline for 2015/16 temperatures. I don't know how long it took him to think up that idea. The difference between the two baselines is 0.42 °C. However, if you took his 0.42 °C as the overall difference between 1997/98 and 2015/16, what Bob has to explain and doesn't is what caused that 0.42 °C increase.

Yet that's misleading too. Bob has arguably exaggerated the warming. The linear trend from the mid 1970s to now is around 0.17 °C/decade. That means an increase of around 0.34 °C over the period from 1996 to 2016. From 1998 to 2016 it's an increase of around 0.31 °C. That means that Bob deducted too much. He subtracted 0.42 °C from the 2015/16 temperatures, which is quite a bit larger than the medium term trend would indicate. But that's not all that's wrong with his "analysis".

Let's see what happens if I line up the 1997/98 temperatures with the 2015/16 temperatures, deducting Bob's 0.42 °C and comparing it with lining up subtracting the linear trend (0.31 °C). First, a plot showing the monthly global temperature anomalies for 2015/16 and 1997/98, after deducting the long term trend from the 2015/16 data. I've kept the baseline at the average of January to March inclusive for 1997, as in Bob's chart:

Figure 6 | Comparison of monthly global surface temperature for 1997/98 and 2015/16 by removing the linear trend from the 2015/16 data. Data source: NOAA.

Compare that with a plot as Bob plotted it. In his chart he aligned the charts by using the 1997 January to March average as the baseline for the 1997/98 plot, and the 2015 January to March average as the baseline for the 2015/16 plot.

Figure 7 | Comparison of monthly global mean surface temperatures for 1997/98 and 2015/16 using Bob Tisdale's flawed alignment. Data source: NOAA

You can clearly see the difference. By not using the medium term trend to align the plots, he made it appear that the current temperatures are lower than would be expected even without any greenhouse warming.

Of course, using any three month baseline is quite silly. Let me show you what happens if you use Bob's different three month average baselines and extend them. You can see how much the charts diverge, because Bob's subtraction of 0.42 °C is around 0.11 °C too great.

Figure 8 | Illustration of the impact of Bob Tisdale using an average of different three month periods to "align" 2015/16 and 1997/98 data. Data source: NOAA

To compare, here is the chart with the alignment I described above. That is, the plots are aligned with the 1997 Jan to March average being the zero line, and 2015/16 data has the linear warming trend removed. That is, 0.31 °C is deducted from each month's temperature. As you can see, the plots align better over the longer period.

Figure 9 | Illustration of the different years aligned by removing the linear trend from the 2015/16 data. Data source: NOAA

Bob tries to excuse his actions

Bob added a note to his charts, which he probably thinks gives him an out. But it doesn't:

Notes about Figure 2: It compares the responses of global surface temperatures to the 1997/98 and 2015 El Niño events. The data have been normalized to the first 3 months of their respective first years. The normalization was done so that we can easily compare, visually, the responses of global surface temperatures to the two comparably sized strong El Niño events. This is not an attempt to hide the fact that global surfaces have warmed between the two events, according to the NOAA land+ocean data. In Figure 2, we’re simply providing a side-by-side comparison.

The reason it's off is that even were he just wanting to see how the two El Ninos differed, he subtracted too much from the 2015/16 data for a proper comparison.

Without greenhouse warming, it would be colder now

Bob's flawed attempt at comparing 2015/16 with 1997/98 isn't the worst part of his analysis. What's worse is that he ignores the increase in global mean surface temperature of the past 18 years.

What Bob doesn't acknowledge or even mention is the increase in temperature between the late 1990s and recent years. That wasn't caused by his El Nino. Below is a chart showing the ENSO years from 1997 to now. There were:

• eleven La Nina years
• nine El Nino years
• four ENSO neutral years.

That adds up to more than the total number of years because some years had both a La Nina and an El Nino as shown in the chart below:

Figure 10 | Annual global mean surface temperature anomalies from 1997 to 2015, with ENSO years marked. Data source: GISS NASA

In other words, there were more periods of cooling ENSO events than there were of warming ENSO events. If there were no greenhouse warming, then arguably the temperature would be lower now, not higher than it was in 1997/98.

Tell your readers, Bob - just how do you explain that?

From the WUWT comments

The nutters are out in force, but there is some pushback. It's good to see a few people picking up Nick Stokes baton, and with some humour, too :)

Tom Halla harks back to the Byzantine and is wrong when he thinks it was "nearly as warm" eighteen years ago (see Figure 3 above especially):

March 22, 2016 at 10:39 am
It does get a trifle byzantine when the temperature records have been “corrected”, and you have to remember that 1997-98 was probably nearly as warm as 2015-16, not notably cooler. Does Winston Smith work at NASA GISS or NOAA?

Rex has no understanding of what the rise in global surface temperature means. I wonder if he knows that the Little Ice Age was not nearly as cold even at its coldest, as 2015 was hot:

March 22, 2016 at 10:47 am
” Earth got so hot last month …” thus illustrating why climate
scientists feast on ‘anomalies’ rather than absolutes: it allows
them to use terms like hot / hotter / hottest, when the temps
are above some mean or norm : 1901-2000 for heavens sake.
(Why not 1900-1999??). Of course it’s not really ‘hot’ at all.
A mean global average temperature or 14.6 or so has hardly
taken the chill off the air. I live in New Zealand, and over the
years have been told by various Australians that on West Island
they don’t consider it ‘hot’ until the temps hit 35C or so.
So, please, can we stop all this ‘hot’ nonsense.

Here's a chart that I call "hot" - and that doesn't include anything from this year. It's got the northern hemisphere from paleo proxies vs global for the instrumental. You'll have to forgive me that. It's the northern hemisphere that would have been colder than it was globally in the cold times, also the northern hemisphere would show a higher anomaly than globally in the hot times - so you could say this chart errs on the conservative side:

The "thought" from philincalifornia doesn't make any sense:

March 22, 2016 at 10:55 am
“It’s on land. It’s in the oceans. It’s in the upper atmosphere. It’s in the lower atmosphere.”, and it’s further strong evidence that it’s not CO2 that’s doing it.

David S ignores all the weird weather, record floods, drought and more from around the world and says:

March 22, 2016 at 11:03 am
Besides,the staggering and alarming rise in temperature was the the staggering and alarming lack of climate related deaths,nor sea level rise,nor instant starvation. The temperature rise is only part of the alarmism. The second requirement is some level of human devastation. I don’t even think we could term the February temperatures as more than mildly uncomfortable. 

spaatch tries to inject some reality with a chart from GISS NASA:

March 22, 2016 at 12:56 pm
This chart does it for me…

Bob Tisdale claims that proper charts are misleading propaganda from realclimate. He got it wrong as usual, including the source. He's gone over the edge. As a semi-professional disinforming pseudo-science quack, Bob probably sees it as his job to convince people that it's anything but the increase in greenhouse gases that are causing the long term warming. He's wrong. It's not warming from blobs and ENSO events. It's greenhouse warming that is causing blobs and El Ninos and La Ninas to be so hot.

March 22, 2016 at 2:53 pm
spaatch, your misleading graph (propaganda from RealClimate) doesn’t answer Martin A’s question. It does not reflect how strong El Nino events contribute to long-term global warming, nor does it reflect the natural contribution of The Blob to the global temperatures in 2014 and 2015 and El Nino conditions in 2015.

Bob Tisdale has a boring refrain. His "theory" is that the world is warming because it's getting hotter. Duh! The world of Bob is just one big blob plus an ENSO.

March 22, 2016 at 2:32 pm
Martin A asks: “Why does El Nino make it warmer?”
In the previous post about the GISS data, I wrote:
We’ve also discussed and illustrated for many years that the long-term effects of strong El Niño events cannot be removed from the instrument temperature record with statistical models like Tamino’s. That is, strong El Niño events contribute to long-term global warming by releasing vast amounts of sunlight-created warm water from beneath the surface of the western tropical Pacific and relocating it to the surface. That’s the simplest explanation of how a strong El Niño contributes to long-term global warming. Some of that warm water released by the El Niño in turn releases heat to the atmosphere, primarily through evaporation. But the remaining warm waters (the leftovers) don’t magically disappear after the El Niño, as Tamino and some from the climate science community would like you to believe. See the discussions of “big jumps” in the Open Letter to the Royal Meteorological Society Regarding Dr. Trenberth’s Article “Has Global Warming Stalled?”

spaatch pithily points to Bob's silliness:

March 22, 2016 at 4:44 pm
That’s silly. The Enso is just an oscillation. Heat is released and heat is taken in. It’s in balance. It’s the warming from C02 that is making the temps rise over the long term.

charles nelson wonders if he's the only person to regard the heating of the Arctic as a cooling event.

March 22, 2016 at 2:07 pm
Am I the only one who considers a massive influx of warm (therefore moist) air into the subzero polar regions to actually constitute a massive COOLING event?
I mean…what happened to all the (warmth) moisture when it changed phase in the darkness up there…snow perhaps? Ice maybe?

As Alf Fass says, maybe not at WUWT:

March 22, 2016 at 2:10 pm
“Am I the only one who considers a massive influx of warm (therefore moist) air into the subzero polar regions to actually constitute a massive COOLING event?”
Today and here, probably not.

That's as good a note as any to end on.