From the “make up your mind” department:
Last year, he told BBC News that post-1995 warming was not significant – a statement still seen on blogs critical of the idea of man-made climate change.
But another year of data has pushed the trend past the threshold usually used to assess whether trends are “real”. Dr Jones says this shows the importance of using longer records for analysis. Short summary: Post 1995 warming now “significant” according to Jones Story title: Global warming since 1995 ‘now significant’
Full story here:
http://www.bbc.co.uk/news/science-environment-13719510
Story submitted by WUWT reader Chris Phillips
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Sean Peake,
I thought that was James Hansen.
@Wade
“. Consider the history of earth, it cannot go from insignificant warming to significant warming in 100 years, much less 1 year. “
I suggest researching what “statistical significance” is. It isn’t what you think it is.
Don’t bother about cherry-picking etc. Focus on the undoubted fact that you can’t, simply can’t re-analyze data repeatedly using standarrd statistical methods. It’s grade 1 statistics class. Don’t go there. If you do it 20 times, chances are that you’ll get a positive answer
… and besides, we’ve had a whole year to adjust the data from 1995
onward to make sure any trend we want to see would
qualify as “significant”.
This continued flurry of warmist “Team” announcements seems to
be a concerted effort to prop up perceptions of the old Hockey Stick and
it’s “verifying” spawn… by implication vindicating Mike Mann and
increasing the lobbying to have his legal troubles in Viriginia quashed.
Any e-mails that Mike had stashed in that server at the University of
Virginia with/to/from Phil Jones that didn’t make the Climategate
release are just more chickens waiting to come home to roost starting
this August.
They’re making hay while the sun don’t shine.
Sorry for the multiple metaphors.
These comments are still tough to edit.
Lucia and I both wrote posts on the subject:
http://rankexploits.com/musings/2011/statistical-significance-since-1995-not-with-hadcrut/
http://noconsensus.wordpress.com/2011/06/11/experts/
Smokey, Hansen is Barney
Jones failed to mention that his statement is only true for the “variance adjusted” version HadCRUT3v and not the original HadCRUT3.
I poked around the CRU website a bit but was not able to figure out when they updated to HadCRUT3v. Can someone more familiar with the datasets tell us when the variance adjusted version was released to the public?
JohnWho says:
June 11, 2011 at 11:39 am
=======================================
John, He’s right, and he’s lying at the same time………
The extra year of temperature data took them through 2010, right before temperatures starting falling fast…
So he can say “Last year’s analysis, which went to 2009, did not reach this threshold; but adding data for 2010 takes it over the line.”
He won’t be able to say that next year…………….
……….and it implies that he’s too stupid to look at current temperature data
….or he’s lying
..
Eh.. I’m OK with it getting warmer. I like warmer weather myself. I don’t buy the “doom and gloom” stuff though associated with it. It’s not like it’s warming 1 degree per year or even every six months.. I think I can adapt at this rate.
Jones is a Welsh name. It snowed in Wales on Friday.
http://www.bbc.co.uk/news/uk-wales-north-west-wales-13731216
I don’t understand this post!! I don’t get it!
“Phil Jones does an about face on “statistically significant” warming” Is it because basically (in my own words) he said statistics are significant in showing a warming trend but now that they do not show a warming trend the statistics are now insignificant in showing a warming trend?
Wasn’t last year an ENSO peak? There is a strong whiff cherry-picking in this result.
Even if a “convenient” result is now available, Jones should have given the it a couple of years to become more entrenched in the data. By making this announcement, he has taken the risk that crossing of a threshold is just a short-term phenomenon. Could be more backtracking in the pipeline, given time.
Will there be a big announcement if the result goes the other way next year? I kinda doubt it. All we’ll have is the worry-squad running about bleating that Jones has declared a significant positive trend.
Watch this space folks – it will be worth coming back to.
Wade wrote:
“Consider the history of earth, it cannot go from insignificant warming to significant warming in 100 years, much less 1 year.”
Do you regard the ending of the Little Ice Age as something insignificant? Many of the recent commentators on this blog tend to discredit sceptical arguments by simply making unsubstantiated assertions or heaping abuse on climate warmists.
Jones may be wrong to claim that recent warming is statistically significant. My knowledge of statistics is not nearly good enough for me to judge. However, in principle there seems to be nothing wrong with his claim that an extra year of data could take things from just below the level of statistical significance to just over it. Therefore unless commentators have a good knowledge of statistics, or have sensible comments to make about the quality of the data, it would be sensible not to criticise him.
Even if Jones is 100% right the data would simply indicate that warming has taken place. It would not tell us what the cause or causes of that warming were.
I could be wrong here, but based on my understanding of the following graphs with their 95% levels, I completely agree with the statement: “Last year’s analysis, which went to 2009, did not reach this threshold; but adding data for 2010 takes it over the line.”
http://www.metoffice.gov.uk/hadobs/hadcrut3/diagnostics/global/nh+sh/
HOWEVER, in my opinion, I believe Dr. Jones was not wise to draw attention to this fact at this time. The site above has the data to the end of April and as we know, 2011 has been one of the cooler ones of the last 15 so far. And if there is no sudden heating in the next 6 months, then at the end of 2011, Dr. Jones can probably say there has been no statistical warming for 17 years.
I only remember Paul having one revelational reversal on the road to Damascus; our boy Phil has had two.
Or, rather, I think it went this way …..
Our Phil, long on the gravy train of global warming, admits, under pressure of public scrutiny, that, in fact, there is nothing unusual about current temperatures. He is stressed to hell and suffering.
He is given a respite … a little R & R… and now he is fortified by his colleagues and paymasters, and now states:
The recent global wearming IS significant.
The money continues to flow and his retirement now has financial security. How he will live with his conscience, as clearly he is a consciencious man, I do not know.
From the BBC article:
“By widespread convention, scientists use a minimum threshold of 95% to assess whether a trend is likely to be down to an underlying cause, rather than emerging by chance.”
This is actually not true at all. In the social sciences where data is very hard to come by, perhaps this would work. They use 2 standard-deviations (95% chance it’s not just random fluctuations) as “proof”. I know that in physics people tend to ignore anything below 3 standard deviations (99.87% chance it’s not just random) and don’t call it proof below 5 (99.99997% chance it’s not just random). This is not an about-face on the data. It is an about-face on his willingness to call it significant. He could easily have used 1 standard deviation last time and called the result “significant” if he wanted, just as he now does with 2.
Is it statistically significant that there has been no warming at all since 2003?
The global ocean doesn’t lie. It hasn’t risen at all since 2003. Glacial melt and thermal expansion halted.
How fun, it turns out that the barely significant value I found turned out to be incorrect according to Dr. Jones himself. His own paper recommends using the gridded data, which does not yet reach significance – just barely.
RE HenryP and Gibraltar comment, above.
The discrepancy between Gibraltar and mainland Spanish weather stations data may, in part, reflect met station site differences. For example, whereas Gibraltar and Malaga are relatively near one another and at sea level, Granada is in the sierras and over 100 miles away. The Rock of Gibraltar is often shaded for much of a sunny day beneath the famous Levanter cloud cap which ‘sits’ over the limestone peak when winds blow from the east, i.e. out of the Mediterranean Sea. Daily max temperatures in summer at Gibraltar are usually 2-3C lower than at Malaga (airport), according to Daily Telegraph daily reports. As for Tangier, in Morocco, one might expect climatic influences often to differ from those affecting Gibraltar temperatures?
Lucia and Jeff Id have done have done statistical analyses, but for those without that kind of background, let’s put things in perspective. The Global HADCRUT linear trend from Jan 1995 to Dec 2009 was 1.16 deg C per Century. The linear trend from Jan 1995 to Dec 2010 was 0.01 deg C per CENTURY higher at 1.17 deg C per Century.
http://i55.tinypic.com/8zh4s5.jpg
Every tornado is significant to the ones who suffer! Just like a good soaking rain is disastrous to an Ant mound!
New paper shows Western N. America drought was far more extreme and variable PRIOR to 500 years ago.
http://hockeyschtick.blogspot.com/2011/06/new-paper-shows-western-n-america.html
The variations; are there, have been there, and will be there!
There are patterns in the variations, but the patterns will never repeat exactly . . . as we, as an earth within a solar system, within a galaxy are in constant motion . . .
We know not where we have been in the long term . . . and WE know not where we go . . . I leave that to the astronomers to discern . . . in about 10,000 years of data . . . . of which we don’t even have a history of yet . . . . Honestly we, you, they are simply educatedly’ guessing . . .
Generally, speaking, all the constant motion, is why the sun’s heat patterns have more than just the @ur momisugly 11 yr variations . . . and it is understood they are not the only considerations of climate change . . . or weather in general for that matter . . . . “Many say find the cause, and there lies the cure!” In this case it is “Find the causes, in their proper magnitudes, and there lies the future!”
In my opinion . . . of course!
ps.. the new format is very awkward for me!
Yeah, sure — this is a reliable source. Grant money runs out …
I wonder if Jones will attempt to do climate science again? Maybe he could go to the South Pole and do a study on UHI. He did a UHI study in London. Makes about as much sense as one at the South Pole.
Yes, it’s Dr Phil “the Zombie” Jones, as in one who is trying to raise himself from the dead.
sharper00 says:
June 11, 2011 at 11:09 am
“If I say “It’s hot today” on one day and “It’s cold today” on a different day, is that an about face too?”
That’s a pretty stupid analogy.
A little station fudge here, a little station nudge there, and .o1C/Century is suddenly significant.
Phil Jones just pulled a statistically Hansenized rabbit out of the hat.
Oh what an insignificant looking web is woven.