Showing posts with label Temperature graphs. Show all posts
Showing posts with label Temperature graphs. Show all posts
January 1, 2018
March 11, 2010
The case against the hockey stick
The "hockey stick" temperature graph is a mainstay of global warming science. A new book tells of one man's efforts to dismantle it—and deserves to win prizes Andrew Montford’s The Hockey Stick Illusion is one of the best science books in years. It exposes in delicious detail, datum by datum, how a great scientific mistake of immense political weight was perpetrated, defended and camouflaged by a scientific establishment that should now be red with shame. It is a book about principal components, data mining and confidence intervals—subjects that have never before been made thrilling. It is the biography of a graph.
FROM-Prospect
Matt Ridley
I can remember when I first paid attention to the “hockey stick” graph at a conference in Cambridge. The temperature line trundled along with little change for centuries, then shot through the roof in the 20th century, like the blade of an ice-hockey stick. I had become somewhat of a sceptic about the science of climate change, but here was emphatic proof that the world was much warmer today; and warming much faster than at any time in a thousand years. I resolved to shed my doubts. I assumed that since it had been published in Nature—the Canterbury Cathedral of scientific literature—it was true.
I was not the only one who was impressed. The graph appeared six times in the Intergovernmental Panel on Climate Change (IPCC)’s third report in 2001. It was on display as a backdrop at the press conference to launch that report. James Lovelock pinned it to his wall. Al Gore used it in his film (though describing it as something else and with the Y axis upside down). Its author shot to scientific stardom. “It is hard to overestimate how influential this study has been,” said the BBC. The hockey stick is to global warming what St Paul was to Christianity.
Of course, there is other evidence for global warming, but none of it proves that the recent warming is unprecedented. Indeed, quite the reverse: surface temperatures, sea levels, tree lines, glacier retreats, summer sea ice extent in the Arctic, early spring flowers, bird migration, droughts, floods, storms—they all show change that is no different in speed or magnitude from other periods, like 1910-1940, at least as far as can be measured. There may be something unprecedented going on in temperature, but the only piece of empirical evidence that actually says so—yes, the only one—is the hockey stick.
And the hockey stick is wrong. The emails that were leaked from the University of East Anglia late last year are not proof of this; they are merely the icing on the lake, proof that some of the scientists closest to the hockey stick knew all along that it was problematic. Andrew Montford’s book, despite its subtitle, is not about the emails, which are tagged on as a last chapter. It is instead built around the long, lonely struggle of one man— Stephen McIntyre—to understand how the hockey stick was made, with what data and what programs.
A retired mining entrepreneur with a mathematical bent, McIntyre asked the senior author of the hockey stick graph, Michael Mann, for the data and the programs in 2003, so he could check it himself. This was five years after the graph had been published, but Mann had never been asked for them before. McIntyre quickly found errors: mislocated series, infilled gaps, truncated records, old data extrapolated forwards where new was available, and so on.
Not all the data showed a 20th century uptick either. In fact just 20 series out of 159 did, and these were nearly all based on tree rings. In some cases, the same tree ring sets had been used in different series. In the end the entire graph got its shape from a few bristlecone and foxtail pines in the western United States; a messy tree-ring data set from the Gaspé Peninsula in Canada; another Canadian set that had been truncated 17 years too early called, splendidly, Twisted Tree Heartrot Hill; and a superseded series from Siberian larch trees. There were problems with all these series: for example, the bristlecone pines were probably growing faster in the 20th century because of more carbon dioxide in the air, or recovery after “strip bark” damage, not because of temperature change.
This was bad enough; worse was to come. Mann soon stopped cooperating, yet, after a long struggle, McIntyre found out enough about Mann’s programs to work out what he had done. The result was shocking. He had standardised the data by “short-centering” them—essentially subtracting them from a 20th century average rather than an average of the whole period. This meant that the principal component analysis “mined” the data for anything with a 20th century uptick, and gave it vastly more weight than data indicating, say, a medieval warm spell.
Well, it happens. People make mistakes in science. Corrections get made. That’s how it works, is it not? Few papers get such scrutiny as this had. But that is an even more worrying thought: how much dodgy science is being published without the benefit of an audit by Mcintyre’s ilk? As a long-time champion of science, I find the reaction of the scientific establishment more shocking than anything. The reaction was not even a shrug: it was shut-eyed denial.
If this had been a drug trial done by a pharmaceutical company, the scientific journals, the learned academies and the press would have soon have rushed to discredit it—and rightly so. Instead, they did not want to know. Nature magazine, which had published the original study, went out of its way to close its ears to McIntyre’s criticisms, even though they were upheld by the reviewers it appointed. So did the National Academy of Sciences in the US, even when two reports commissioned by Congress upheld McIntyre. So, of course, did the IPCC, which tied itself in knots changing its deadlines so it could include flawed references to refutations of McIntyre while ignoring complaints that it had misquoted him.
The IPCC has taken refuge in saying that other recent studies confirm the hockey stick but, if you take those studies apart, the same old bad data sets keep popping out: bristlecone pines and all. A new Siberian data series from a place called Yamal showed a lovely hockey stick but, after ten years of asking, McIntyre finally got hold of the data last autumn and found that it relied heavily on just one of just twelve trees, when far larger samples from the same area were available showing no uptick. Another series from Finnish lake sediments also showed a gorgeous hockey stick, but only if used upside down. McIntyre just keeps on exposing scandal after scandal in the way these data were analysed and presented.
Montford’s book is written with grace and flair. Like all the best science writers, he knows that the secret is not to leave out the details (because this just results in platitudes and leaps of faith), but rather to make the details delicious, even to the most unmathematical reader. I never thought I would find myself unable to put a book down because—sad, but true—I wanted to know what happened next in an r-squared calculation. This book deserves to win prizes.
Oh, and by the way, I have a financial interest in coal mining, though not as big as Al Gore has in carbon trading. Maybe you think it makes me biased. Read the book and judge for yourself.
More...
December 17, 2009
Climategate: Faster and Faster, the Dominos Fall
With the revelation about the cherrypicked Russian stations (plus six other freshly, independently discovered problems), the real story of how we got here just took a shape.
The article reports that the IEA had taken a new look at the data used in the Intergovernmental Panel for Climatic Change (IPCC) reports. These reports, which became the basis for warnings of dramatic human-caused global warming that led to calls for extensive regulation and to the current climate change conference in Copenhagen, are based on world temperature estimates using measurements from thousands of reporting sites throughout the world.
Novosti reported that the data used for temperature measurements in Russia appeared to have been carefully chosen from the warmest reporting sites. If an average were taken over all Russian reporting sites, then there was little or no warming to report.
Using only the sites chosen for the IPCC reports, Russia instead showed significant warming, with a “hot spot” over Eastern Siberia.
This story turned out to fit neatly with some of the CRU emails. As Steve McIntyre discusses at Climate Audit, one email from Phil Jones to Michael Mann says:
So here’s a puzzle. What papers is Jones referring to, and how did they claim CRU had it “wrong over Siberia”? More...
In this figure, the blue line is the raw data. The black line is the adjustments that had been applied to that data, and the red line is the result following the adjustments.
The data used by the IPCC instead shows warming four times greater, 2.8°C per century, an adjustment of about 2°C.
What can be said is this: We now have substantial evidence, from several independent sources, that the data used as the basis for the IPCC report has been adjusted in undocumented ways, and those adjustments account for nearly all the warming we are told has been caused by humans.
Until the data is re-examined, fully, openly, and transparently, it is impossible to conclude how much of a contribution to global climate change humans have made, or whether that contribution has been made by human-generated CO2. And without knowing that, attempts to “fix the problem,” through cap and trade or Copenhagen agreements, is misguided at best — and dangerous at worst.
FROM-Pajamas Media
by Charles Martin
The Climategate files were made public just a month ago, and the email messages that were revealed have already had real impact. The emails show us scientists being petty and political, even corrupt. Suppressing dissenting science and perhaps even violating the law to prevent data from being shared with the rest of the world. They show us people with failings, egos against egos. But the emails themselves aren’t enough to call the overall science of CO2-driven, human-caused climate change into question.
The Climategate emails, however, make up only five percent of the Climategate files. The other 95 percent, the programs and data and documents, are where the real story is hiding. That story has begun to come out, in several independent analyses of the data we have, using hints from the emails and from other files and raw data that is available from other sources.
A story is beginning to take shape. This story broke into the world media Wednesday. An article in RIA Novosti, the Russian state-owned news service, states:
The Climategate files were made public just a month ago, and the email messages that were revealed have already had real impact. The emails show us scientists being petty and political, even corrupt. Suppressing dissenting science and perhaps even violating the law to prevent data from being shared with the rest of the world. They show us people with failings, egos against egos. But the emails themselves aren’t enough to call the overall science of CO2-driven, human-caused climate change into question.
The Climategate emails, however, make up only five percent of the Climategate files. The other 95 percent, the programs and data and documents, are where the real story is hiding. That story has begun to come out, in several independent analyses of the data we have, using hints from the emails and from other files and raw data that is available from other sources.
A story is beginning to take shape. This story broke into the world media Wednesday. An article in RIA Novosti, the Russian state-owned news service, states:
On Tuesday, the Moscow-based Institute of Economic Analysis (IEA) issued a report claiming that the Hadley Center for Climate Change based at the headquarters of the British Meteorological Office inExeter (Devon, England) had probably tampered with Russian-climate data.
The article reports that the IEA had taken a new look at the data used in the Intergovernmental Panel for Climatic Change (IPCC) reports. These reports, which became the basis for warnings of dramatic human-caused global warming that led to calls for extensive regulation and to the current climate change conference in Copenhagen, are based on world temperature estimates using measurements from thousands of reporting sites throughout the world.
Novosti reported that the data used for temperature measurements in Russia appeared to have been carefully chosen from the warmest reporting sites. If an average were taken over all Russian reporting sites, then there was little or no warming to report.
Using only the sites chosen for the IPCC reports, Russia instead showed significant warming, with a “hot spot” over Eastern Siberia.
This story turned out to fit neatly with some of the CRU emails. As Steve McIntyre discusses at Climate Audit, one email from Phil Jones to Michael Mann says:
Recently rejected two papers (one for JGR and for GRL) from people saying CRU has it wrong over Siberia. Went to town in both reviews, hopefully successfully. If either appears I will be very surprised, but you never know with GRL.
So here’s a puzzle. What papers is Jones referring to, and how did they claim CRU had it “wrong over Siberia”? More...
While the Novosti report has gotten the most attention, it’s not the only such report. The Climategate files forced the UK Meteorological Office to make at least part of their raw data available. One of the first was Willis Eschenbach, at Watts Up With That. Read the whole discussion and also Eschenbach’s answer to a critique published in the Economist for the details, but here is the “money shot”:
In this figure, the blue line is the raw data. The black line is the adjustments that had been applied to that data, and the red line is the result following the adjustments.
The next domino was a study by Dr. Richard Keen of the University of Colorado that was reported at the Air Vent blog. In it, Dr. Keen compares the raw data from the National Climate Data Center (NCDC) with data from the Global Climate historical network, the adjusted data as published in the IPCC report. Dr. Keen finds that the raw data does indeed show an upward trend of 0.69°C per century, which he believes is explained by the “Pacific Decadal Oscillator,” a well known long-term phenomenon.
The data used by the IPCC instead shows warming four times greater, 2.8°C per century, an adjustment of about 2°C.
Other such comparisons followed: Data from around Nashville; data collected in Antarctica, which, after adjustment, comes out to be from a single site near the ocean; data from the Baltic and Scandinavian countries; even in Central Park.
In all of these cases, there are mysterious, unexplained warming adjustments for the last part of the century.
It ought to be said that these adjustments don’t necessarily prove the data has been purposefully fudged. Handling this kind of large data set requires using statistical techniques to try and make the data consistent. (Dr. William M. Briggs, a Pajamas Media contributor, has a nice series starting here for people who want to read the technical details.) On the other hand, at some point we have to remember Goldfinger’s Law: Once is accident, twice coincidence, three times is enemy action. And the problem is, without the raw data, and without a clear explanation of the process by which the data has been adjusted — something that seems unlikely in light of the HARRY_READ_ME.txt file — there is no way to tell what the adjustments are based on. The CRU clique asks us to trust them, when the history in the Climategate emails doesn’t say much to encourage trust.
It ought to be said that these adjustments don’t necessarily prove the data has been purposefully fudged. Handling this kind of large data set requires using statistical techniques to try and make the data consistent. (Dr. William M. Briggs, a Pajamas Media contributor, has a nice series starting here for people who want to read the technical details.) On the other hand, at some point we have to remember Goldfinger’s Law: Once is accident, twice coincidence, three times is enemy action. And the problem is, without the raw data, and without a clear explanation of the process by which the data has been adjusted — something that seems unlikely in light of the HARRY_READ_ME.txt file — there is no way to tell what the adjustments are based on. The CRU clique asks us to trust them, when the history in the Climategate emails doesn’t say much to encourage trust.
What can be said is this: We now have substantial evidence, from several independent sources, that the data used as the basis for the IPCC report has been adjusted in undocumented ways, and those adjustments account for nearly all the warming we are told has been caused by humans.
Until the data is re-examined, fully, openly, and transparently, it is impossible to conclude how much of a contribution to global climate change humans have made, or whether that contribution has been made by human-generated CO2. And without knowing that, attempts to “fix the problem,” through cap and trade or Copenhagen agreements, is misguided at best — and dangerous at worst.
October 1, 2009
July 31, 2009
July 3, 2009
June 12, 2009
As you can see:
The trends for both UAH and RSS are negative since 2001 with RSS having the larger negative trend
FROM- The Blackboard
UAH vs RSS Trends since 2001 or 2000
More...
June 5, 2009
May 30, 2009
May 15, 2009
April 13, 2009
I thought they were still in Memphis
This is another of those stories which is both misleading and difficult to prove. Perhaps the first thing that should be determined, is the observed climate change in Yellowstone caused by CO2? Of course it is assumed that there is both unnatural climate change in Yellowstone and that it is caused by CO2. First the headline and a couple of paragraphs.
Are Yellowstone National Park's Grizzlies Changing Denning Habits Due to Climate Change?
Are grizzlies in Yellowstone National Park altering their long winter's slumber due to a changing climate? Federal wildlife biologists think so, and want to take a closer look into this possibility.
"We've detected a slightly later period of denning in fall in male bears," Chuck Schwartz of the U.S. Geological Survey, who heads the Interagency Grizzly Bear Study Team, told the Great Falls Tribune. "We think that's related to climate warming.".....
So we learn that climate change is affecting the Grizzlies in Yellowstone. We have another couple of paragraphs about the changing climate in Yellowstone, snow and etc.(please read). Then we come to this:
...Unfortunately, there’s mounting evidence that Yellowstone’s winters are becoming milder and drier. During the past half-century snow depths across the park have steadily declined, particularly in the spring months, and temperatures have been on the rise. Driving these changes is the shifting El Nino Southern Oscillation away from the La Nina phase that produces colder, snowier winters, to the warmer, drier El Nino phase....
So in fact it is actually a natural, normal climate condition which has caused this. With the shift of the PDO this situation could very likely change anyway. Upon reading the entire article there is really nothing ominous about the whole issue anyway, but we have to get the climate change angle into the lead, oh well.
But out of curiosity I went to two weather stations in Yellowstone from the US Historical Climate Network Site and downloaded the graphs of average yearly mean temperatures in Yellowstone which go back a long way. Click on the links and you may feel less alarmed about the grizzlies.
West Yellowstone
Yellowstone Park Mammoth
April 3, 2009
READ ALL ABOUT IT!
from Roy Spencer
March 2009 Global Temperature Update
…hot off the press…N. Hemisphere & tropics really cooled off last month.
YR MON GLOBE NH SH TROPICS
2009 1 0.304 0.443 0.165 -0.036
2009 2 0.347 0.678 0.016 0.051
2009 3 0.208 0.313 0.104 -0.150
Subscribe to:
Posts (Atom)