Deniergate Papers I – Dr. Phil Jones & the 15 Years

Posted on February 17, 2010

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1. The British Press Fool Simple Sam

Clop-clop.  Clop-clop.  Simple Sam’s silly slippers slapping in the hallway tell me he’s going to bring me another denialist howler today.  And sure enough, here he is, a smirk on his face, a [virtual] copy of the Daily Mail under his arm.

(Sam can carry around virtual copies because he’s kind of virtual himself.)

“Here it is,” says Simple Sam.  “Proof that global warming isn’t happening.”

Excellent, Sam, and the UK newspaper the Daily Mail found this out, did they?  Remarkable.  I didn’t even know they had a scientific staff.  So who headed the study?

“Um, the article writer is Jonathan Petre,” says Sam.

And what area of science does Dr. Petre… It is Dr. Petre, isn’t it?

“No, I don’t think so,” says Sam.

What does Mr. Petre do, Sam?

“He writes articles.”

Astounding, Sam.  You’re saying that, despite the fact there are 20,000 climatologists on this planet, it was a journalist who disproved global warming?

“No, he was talking about an interview with Dr. Phil Jones of the University of East Anglia,” says Sam.

What was the result of that interview, Sam?

“That there has been no statistically significant warming in the last fifteen years!” says Sam, with a smile so triumphant it made me step back.

So that’s what Phil Jones said to Mr. Petre, Sam?

“No,” says Sam.  “Phil Jones didn’t actually talk to Petre.  It was an interview with the BBC.”

So, show me the interview, Sam.

“I don’t have the interview.”

You’re willing to accept somebody’s interpretation of an interview, and you haven’t even looked at the interview?  Sam, Sam.  So lazy.  So sloppy.  I’m afraid I’m going to have to send you back to Remedial Research 101.  Yes, it’s back to class for you, Sam.

“Not again?” wails Sam.

Repeating the class fourteen times is obviously not enough, Sam.  Until you learn to check your sources, you’ll always be a fool.  You’ll always be nothing more than Simple Sam, crackpot denier man, a figure of fun. But … but school doesn’t start until tomorrow, Sam.  For now go get the BBC interview, and we’ll find out what the eminent Dr. Jones really said.

“Dr. Jones isn’t eminent,” says Sam, his mouth petulant.

Then why does his opinion matter, Sam?

Sam didn’t want to answer.  He went to get the BBC interview.

2)  Simple Sam Fools Himself

Here comes Sam back, and he still has a smug look on his face.  So what’s making him happy?

“Here it is,” he says.  “Here’s where Phil Jones says it.”

Good, Sam.  A good start.

“It’s what Jonathan Petre said he said,” says Sam.

Oh, Sam, you were doing so well.  You know that when you are examining any statement you have to look at its context first, to see whether the context illuminates or modifies the meaning in any way.

“Words mean what they mean,” says Sam.

No, Sam.  Words exist in context.  If I ask you every day at the end of your ten mile run, if your feet are sore, and you answer yes, that doesn’t mean your feet are always sore.  If I asked you at random, when you got up, when you went to bed, after a week of bedrest, and you said yes, that would have a different meaning.  Context changes the meaning of your answer, even if your answer is the same.

“Okay, okay,” says Sam.  “Context is not going to change the meaning of what Phil Jones said, anyway.”

Won’t know until we look, will we, Sam?

Here is the first question and answer.

BBC                Do you agree that according to the global temperature record used by the IPCC, the rates of global warming from 1860-1880, 1910-1940 and 1975-1998 were identical?

Jones                An initial point to make is that in the responses to these questions I’ve assumed that when you talk about the global temperature record, you mean the record that combines the estimates from land regions with those from the marine regions of the world. CRU produces the land component, with the Met Office Hadley Centre producing the marine component.

Temperature data for the period 1860-1880 are more uncertain, because of sparser coverage, than for later periods in the 20th Century. The 1860-1880 period is also only 21 years in length. As for the two periods 1910-40 and 1975-1998 the warming rates are not statistically significantly different (see numbers below).

I have also included the trend over the period 1975 to 2009, which has a very similar trend to the period 1975-1998.

So, in answer to the question, the warming rates for all 4 periods are similar and not statistically significantly different from each other.

Here are the trends and significances for each period:

(Dr. Jones then produces the following graph.)

Period              Length                          Trend                           Significance

(Degrees C per decade)

1860-1880       21                                0.163                           Yes

1910-1940       31                                0.15                             Yes

1975-1998       24                                0.166                           Yes

1975-2009       35                                0.161                           Yes

(The first column sets out the years examined on each line.  The second column sets out how long each period of years is.  The third column sets out the average warming per decade for each period.  The fourth column says whether that amount of warming is statistically significant.)

This is not looking good for your argument, Sam.  There is statistically significant warming for all the periods indicated, according to this chart.

“Look at the next question,” says Sam, impatiently.

BBC                Do you agree that from 1995 to the present there has been no statistically-significant global warming?

Jones                Yes, but only just. I also calculated the trend for the period 1995 to 2009. This trend (0.12C per decade) is positive, but not significant at the 95% significance level. The positive trend is quite close to the significance level.  Achieving statistical significance in scientific terms is much more likely for longer periods, and much less likely for shorter periods.

“Jones agrees with the interviewer that there has been no statistically significant warming for the last 15 years!” crows Simple Sam, not bothering to hold back his glee.

That’s not what he says, Sam.  He says that there has been a positive trend of 0.12C per decade—0.18 C of warming during the full period—but this is not significant at the 95% percent level.  Why?  He answers it himself.  “Achieving statistical significance in scientific terms is much more likely for longer periods, and much less likely for shorter periods,” says Dr. Jones.  He means that, in this case, fifteen years of data is too short a time to produce a statistically significant result.

“You’re just trying to wiggle out of what he said,” says Sam.

Not at all, Sam.  Climate, as you climate change deniers never seem to get, is about the big picture.  The rule of thumb in climatology is that climate is measured in 30 year intervals.  That’s just so you can rule out cyclical or atypical trends, and be sure that what you are seeing is real and not just “noise” or random fluctuations.  That’s why, when Dr. Jones says that he can almost find statistical significance in a fifteen year period, that’s astounding in a way opposite to the way the climate change denialists have interpreted it.  To almost find statistical significance in merely fifteen years of data is a testament to how extraordinary that data is, and how rapidly climate change is happening.

“I still think you’re just dodging,” says Sam.

Consider it this way, Sam.  If you showed a doctor specializing in epidemics, statistics showing a disease epidemic in California, Oregon and Washington (all the west coast states, Sam, I know your geography is shaky) and then asked him whether he thought there was a disease epidemic across the United States, he would say that there was not enough information.  That’s all he scientifically could say, Sam, without information more geographically widespread.  Say from New York, Montana and Tennessee.  (Look them up, Sam.)  That’s the way science works.

And because I can see you still don’t believe me, I want you to take ….

A Simple (But Rigged) Test for Climate Deniers.

Sequence [i]   1, 2 …

1.  What’s the next number in the above sequence?  Choose one.

a) 3

b) 4

c) 9

d) There isn’t remotely enough information to answer the question.

For question one,

  • Answer [a] is correct if the sequence is simple counting.  It is also correct if the sequence is an ascending list of prime numbers.  It is also correct if the sequence is in base five rather than base ten.  It is also correct if the sequence consists of counting up and down between one and four.
  • Answer [b] is correct if in the sequence every number is twice the value of the one before.
  • Answer [c] is correct if the sequence is generated by cubing the number before and adding one.

These examples do not exhaust the reasons why any of these answers could be right or wrong.

The answers given do not exhaust the number of correct answers that are possible.

Therefore, the only answer that is unambiguously correct to question one is [d].

———————

Sequence [ii]  1, 2, 3…

2.  What’s the next number in the above sequence? Choose one.

a) 4

b) 5

c) 6

d) There still isn’t enough information to answer the question.

For question two,

  • Answer [a] is correct if the sequence is simple counting.  It is also correct if the sequence consists of counting up and down between one and four.  It is also correct if the numbers are in base five, etc., rather than in base ten.
  • Answer [b] is correct if the sequence is an ascending list of prime numbers.  (Prime numbers are evenly divisible only by one and by themselves.)  It is also correct if the next number is generated by adding the previous two numbers together.
  • Answer [c] is correct if the sequence is generated by adding all the preceding numbers together.

The correct answer to question two is [d].

—————

Sequence [iii]  1, 2, 3, 4 ….

3.  What’s the next number in the above sequence? Choose one.

a) 5

b) 3

c) 10

d) We really need more information than this.

For question three,

Answer [a] is correct if the sequence is simple counting.

Answer [b] is correct if the sequence consists of counting up and down from one to four.

Answer [c] is correct if the sequence is in base five rather than base ten.

The correct answer to question three is [d].

—————

LESSON:  Before you can make any certain or near-certain statements (for example, scientific statements) about how something is going to turn out,  you first have to have data set large enough to rule out, or substantially rule out, alternative explanations.  Any premature statement is not statistically valid, regardless how strongly suggestive it might be.

(That’s  science, Simple Sam.  That’s the way it works.)

—————————————————————————-

Deniergate I conclusions:

Dr.  Phil Jones of the Climate Research Unit of the University of East Anglia did not say what the Daily Mail said he did.

Either his statement was deliberately distorted, or presented in a way that was meant to mislead, it which case it was a lie.

Or his statement was misunderstood, in which case it was an example of denialist stupidity and ignorance of science.

So what do you think, Sam?  Were they lying?  Or were they just stupid?

(Sam is not answering.  Sam is pouting.)

——————————–

See the BBC interview @

http://news.bbc.co.uk/2/hi/science/nature/8511670.stm

See the Daily Mail article @

http://www.dailymail.co.uk/news/article-1250872/Climategate-U-turn-Astonishment-scientist-centre-global-warming-email-row-admits-data-organised.html

See update one year later @

Scientist Says Global Warming Is Now Significant (11June2011)