No evidence at WUWT - a DuKE, global surface temperature, and statistics

Anthony Watts has a new article on his climate conspiracy blog (archived here). It has the title: "Is There Evidence of Frantic Researchers “Adjusting” Unsuitable Data? (Now Includes July Data)". The answer is NO. Or at least none is provided by anyone. Which raises the question of why the title? You'd think he'd at least make up something to appease the mob. All he has is a mish-mash of temperature data from various sources, including lower troposphere data, and land and sea surface data (combined), and sea surface data, interspersed with gobbledegook from one of his long-winded fans. (And July must be a big deal, even though it's already October!)

The authors are listed as follows:

• Professor Robert Brown from Duke University (aka the batty duke or rgbatduke)
• Werner Brozek
• with one of Anthony's pet Anonymous Cowards known as "Just The Facts" as editor.

In regard to whoever is Just The Facts, he or she is a long time regular. Anthony doesn't like people using pseudonyms. Let me correct that. Anthony only likes deniers using pseudonyms. Any normal person who prefers to comment on climate using a pseudonym is castigated by Anthony Watts. (I think Just The Facts is the same person who also posts at WUWT as justthefactswuwt. But I cannot say for sure. It doesn't matter.)

A note on statistical significance: If you want to skip over the meaningless ramble, you can jump straight to the discussion about what statistical significance means. (Hint: a 'not statistically significant' trend doesn't mean that it hasn't warmed.)

More conspiracy theories at WUWT, this time it's HadCRUT4

I don't have time for a long post right now, so I'll just comment on one of today's recycled conspiracy theories at WUWT (archived here). It relates to the newest version of HadCRUT4.

The trio of WUWT record-keepers, Werner Brozek, Walter Dnes and Just The Facts, are musing nefarious intent is behind the release of HadCRUT 4.3.0.0, which replaces version 4.2.0.0:

Why are they changing things so quickly? Do they want to take some of the heat off GISS? Are they embarrassed that Dr. McKitrick has found no statistically significant warming for 19 years and before the ink is barely dry on his report, they want to prove him wrong? Are they determined that by hook or by crook that 2014 will set a new record?

It's a strange question - to complain that improvements are made too quickly. Would they prefer that the scientists sat on the information for a few years? That they kept it hidden?

Their "nefarious intent" musing is one of the classic signs of conspiracy ideation. What this trio are implying that the Met Office Hadley Centre scientists are making up stuff, which is ridiculous. Their tossing in McKitrick's analysis is a distraction. They want to fool people into thinking global warming has stopped. It hasn't. That's probably why this trio are a bit concerned that 2014 might rival the previous hottest years on record - 2010 and 2005. Even without an El Nino (which might still emerge before the end of this year.)

Werner Brozek at WUWT claims that "at least" means "at most"!

Update: See below - I've added a video for Werner Brozek, as I promised in the comments, to help him learn the difference between science and policy and maybe pick up some critical thinking tips.

I read this at Anthony Watts' science-denying blog, WUWT, this evening.  Werner Brozek wrote (archived here):

...204 months is equal to 17 years. In the “Separating signal and noise in atmospheric temperature changes: The importance of timescale” Benjamin Santer et al. stated that:

“Our results show that temperature records of at least 17 years in length are required for identifying human effects on global-mean tropospheric temperature.”

I am sure that I will be corrected if I am wrong, but in plain English, my interpretation of this statement is as follows:

“There is a lot of noise in the climate system and it is quite possible that the noise can mask the effects of man-made carbon dioxide for a period of time. However if the slope is zero for 17 years, then we cannot blame noise any more but we have to face the facts that we humans do not affect the climate to any great extent.”

Is that reasonably accurate interpretation?

No, it's not a reasonably accurate interpretation

What do you think?   Is that a reasonably accurate interpretation?  It would appear to the disinterested reader that Werner has re-interpreted what was written.  In particular he has:

• ignored the two words "at least"
• committed a logical fallacy.

To my mind the first oversight is sufficient to show that Werner is wrong.  Still, I'll present his logical fallacy, which is related to his ignoring the two important words.  It is as follows:

• Santer stated that "to identify human effects at least 17 years of data is required"
• Werner turned this around and basically said "to identify human effects at most 17 years of data is required", which is wrong.

I've written about this before here when Christoper Monckton tried it on.  If you want to know what Santer et al meant, the best way to find out is to go to the paper itself.  In the text you will read how the longer the time period the more the signal emerges from the noise.  They show that multi-decadal records are needed (at least 17 years).  For example, as follows:

• Our estimated signal-to-noise (S/N) ratios for global-scale TLT changes were less than 1.0 on the 10-year timescale (Figure 6c). On the 32-year timescale, however, S/N exceeded 3.9 in all three observational TLT data sets. The latter result shows that natural internal variability, as simulated by current climate models, is a highly unlikely explanation for the observed lower tropospheric warming over the satellite era (Figure 6d). Comparisons between simulated and observed low-frequency TLT variability suggest that our estimates of S/N ratios on 5–20 year timescales are conservative (Figures 9 and 10). The strong timescale dependence of S/N ratios arises primarily because of the large decrease in noise amplitude as the period used for trend fitting increases (Figure 6b).

• The clear message from our signal-to-noise analysis is that multi-decadal records are required for identifying human effects on tropospheric temperature. Minimal warming over a single decade does not disprove the existence of a slowly-evolving anthropogenic warming signal.

Compare 17 years with 34 years of RSS data

The animation below probably says it all.  I've plotted RSS data of the lower troposphere (70S to 82.5N) because that's what Werner Brozek used. The only difference is that Werner plotted monthly data from 1 November 1996 to 31 October 2013 (monthly data is noisier), whereas I've plotted annual data.  The chart shows:

• the first 17 years of the RSS record, 1979 to 1996
• the second (most recent) 17 years, 1996 to 2013 - minus what hasn't happened yet this year and
• the entire 34 year period, 1979 to 2013 (with the current year to date).

Data Source: RSS

Note the R² values.  For the two shorter periods the trend line has not much meaning.  For the longer period of 34 years, the trend is more solid:

• 1979 to 1996 has a steeper slope than the most recent 17 year period (0.07°C/decade), but R² = 0.0893
• 1996 to 2013 is the least steep slope (0.02°C/decade) and R² = 0.0108
• 1979 to 2013 has the steepest slope of all (0.12°C/decade) and R² = 0.4701

For comparison, here is GISTemp global surface temperature anomaly with the trend line plotted from 1971 to 2012:

Data Source: NASA

I have a feeling that Werner Brozek won't be celebrating for too many more months (click the climate models tab here).

From the WUWT comments

Here's a sample (I nearly forgot! - How could I?) - archived here.


ConfusedPhoton says:

November 4, 2013 at 6:55 am
The goal posts will be moved soon and we will see that we need 25-30 years of non warming.
It is a bit like the timing of the end of the world madmen, everytime we reach it some excuse is used and a new date is given.
Do not make the mistake that Climate ” Science” has anything to do with real science!

JimH says he's prepared to wait a bit longer:

November 4, 2013 at 7:02 am
Personally I’m waiting (hopefully) for the 20 year mark. Because then the 1980-2000 (roughly speaking) rise will be no longer than the 2000-2020 level/cooling period. I don’t think AGW will survive that. We’re nearly three quarters of the way there, as the years tick by the warmists will be getting more and more worried. I think post 2015 the cracks will really begin to show as more rats leave the sinking ship.

oppti says - (you'll enjoy this comment!):

November 4, 2013 at 7:15 am
Ric Werme 7:00
Ok so what is the RSS reading for the period 1944-1978?
Climate has long time periodicity, something CO2 has not changed completely!

Alan the Brit says:

November 4, 2013 at 7:39 am
As people have already noted, the goalpost shifting will soon begin, with warmists ready with a veritable bank of excuses as to why the Earth hasn’t warmed or indeed started to cool!!!! Under no circumstances could they be wrong!

highflight56433 says:

November 4, 2013 at 8:09 am
My contention has been that if we dilute the atmosphere’s water vapor with CO2, it will have a cooling effect. There is more correlation to this per the inter-glacial periods.
Also, temperature readings at airports are for the purposes of aircraft performance, not climate monitoring. My contention (lots of contentions) is not to use any airport weather station data. They are heat islands.
Another contention is the sun drives our climate followed by “other stuff.”

Addendum

Richard Milne on critical thinking - separating climate science and politics / opinion / policy.

i

Vendettas and denial on WUWT

Not much happening on WUWT in the past couple of days.  Here's a a rundown on a couple of articles.

Vendetta still being waged

Jim Steele, who I've written about before here and here, continued his lone vendetta against a biologist who he has a grudge against, using WUWT to do it (and to try to get someone to buy his book).  From those previous articles he has no credibility left and I'll not bother with him any further.

Global warming is real

justhefactswuwt and/or werner brozek put up a noisy monthly chart of RSS global temperatures starting at 1997 and says, look, no warming for 200 months.  Then proceeds to work out for how long there has been "no warming" by plotting monthly charts of different data sets - saying 23 years, 18 years etc.  Here's a long term chart from GISTemp, which makes their efforts to deny global warming look silly:

Data source: NASA

Fake sceptics go to an awful lot of trouble in their attempts to disprove global warming.  If only they put as much effort into figuring out how to address the problem.

Here is the RSS chart. It registered a very high anomaly for 1998, the year of the super El Niño.  What will happen the next time we get a super El Niño?

Data Source: RSS

Here is a decadal chart of RSS temperature anomalies.  The first and last decade are, of course, incomplete.

Data Source: RSS

What do you think?  Climate trends are much easier to see in years than in months, because months clog up the data with seasonal fluctuations and noise. Longer term climate trends are even easier to see in decades, because years have noise from year to year natural fluctuations, like ENSO.

Bear in mind, too, that RSS doesn't monitor temperatures right to the top of the poles.  It only goes as high as 82.5 degrees North and South.  So it misses out on some of the Arctic amplification.  Here is GISTemp showing also the temperature 64 degrees and north (the Arctic).

Data source: NASA

From the WUWT comments, lsvalgaard says:

August 25, 2013 at 10:06 am  RSS Flat For 200 Months (Now Includes July Data)
Thus no global cooling…