From NASA: Research Links Extreme Summer Heat Events to Global Warming
A new statistical analysis by NASA scientists has found that Earth’s land areas have become much more likely to experience an extreme summer heat wave than they were in the middle of the 20th century. The research was published today in the journal Proceedings of the National Academy of Sciences.
Earth’s Northern Hemisphere over the past 30 years has seen more “hot” (orange), “very hot” (red) and “extremely hot” (brown) summers, compared to a base period defined in this study from 1951 to 1980. This visualization shows how the area experiencing “extremely hot” summers grows from nearly nonexistent during the base period to cover 12 percent of land in the Northern Hemisphere by 2011. Watch for the 2010 heat waves in Texas, Oklahoma and Mexico, or the 2011 heat waves the Middle East, Western Asia and Eastern Europe. Credit: NASA/Goddard Space Flight Center Scientific Visualization Studio |
Anthony comments on the NASA animation by Dr. James Hansen of surface temperature trends from 1955-1999:
There are many issues with this presentation. It seems to be a big Cherry Picking exercise.
1. Note all of the missing southern hemisphere data. There are operating weather stations during his time, but they are excluded from the analysis. Why?
2. The period chosen, 1955-1999 (in the bell curve animation) leaves out the warmer 1930’s and the cooler 2000’s. Why?
3. The period from 2000-present has no statistically significant warming. Leaving that period out (of the bell curve animation) biases the presentation.
4. The period chosen exhibits significant postwar growth, urbanization is not considered.
5. As for severe weather, Hansen ignores the fact that neither tornadoes nor hurricanes have shown any increase recently. Only smaller tornadoes show an increase, due to reporting bias thanks to easily affordable and accessible technology. NOAA’s SPC reports that July 2012 seems to be at a record low for tornadoes.
6. My latest results in Watts et al 2012 suggest surface station data may be biased warmer over the last 30 years.
The statistics show that the recent bouts of extremely warm summers, including the intense heat wave afflicting the U.S. Midwest this year, very likely are the consequence of global warming, according to lead author James Hansen of NASA’s Goddard Institute for Space Studies (GISS) in New York.
“This summer people are seeing extreme heat and agricultural impacts,” Hansen says. “We’re asserting that this is causally connected to global warming, and in this paper we present the scientific evidence for that.”
Hansen and colleagues analyzed mean summer temperatures since 1951 and showed that the odds have increased in recent decades for what they define as “hot,” “very hot” and “extremely hot” summers.
The researchers detailed how “extremely hot” summers are becoming far more routine. “Extremely hot” is defined as a mean summer temperature experienced by less than one percent of Earth’s land area between 1951 and 1980, the base period for this study. But since 2006, about 10 percent of land area across the Northern Hemisphere has experienced these temperatures each summer.
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James Hansen and colleagues use the bell curve to show the growing frequency of extreme summer temperatures in the Northern Hemisphere, compared to the 1951 to 1980 base period. The mean temperature for the base period is centered at the top of the green curve, while hotter than normal temperatures (red) are plotted to theright and colder than normal (blue) to the left. By 1981, the curve begins to shift noticeably to the right, showing how hotter summers are the new normal. The curve also widens, due to more frequent hot events. Credit: NASA/Goddard Space Flight Center Scientific Visualization Studio |
Comments from Anthony:
This bell curve proves nothing, as it has the same problems with data as the surface temperature visualization above: cherry picking period, missing data, and contradictory severe weather statistics. This is nothing but a political ploy from a man who has abandoned any pretext of professionally done science in favor of activism. However, in spite of this, it will be used as “proof” by non-thinking individuals like Bill McKibben to promote a political end. Prepare for a barrage of such stories trying to link any observed weather aberration to climate. They’ll use the same level of fact checking like we saw with the melting street lamps last week.
In 1988, Hansen first asserted that global warming would reach a point in the coming decades when the connection to extreme events would become more apparent. While some warming should coincide with a noticeable boost in extreme events, the natural variability in climate and weather can be so large as to disguise the trend.
To distinguish the trend from natural variability, Hansen and colleagues turned to statistics. In this study, the GISS team including Makiko Sato and Reto Ruedy did not focus on the causes of temperature change. Instead the researchers analyzed surface temperature data to establish the growing frequency of extreme heat events in the past 30 years, a period in which the temperature data show an overall warming trend.
NASA climatologists have long collected data on global temperature anomalies, which describe how much warming or cooling regions of the world have experienced when compared with the 1951 to 1980 base period. In this study, the researchers employ a bell curve to illustrate how those anomalies are changing.
A bell curve is a tool frequently used by statisticians and society. School teachers who grade “on the curve” use a bell curve to designate the mean score as a C, the top of the bell. The curve falls off equally to both sides, showing that fewer students receive B and D grades and even fewer receive A and F grades.
Hansen and colleagues found that a bell curve was a good fit to summertime temperature anomalies for the base period of relatively stable climate from 1951 to 1980. Mean temperature is centered at the top of the bell curve. Decreasing in frequency to the left of center are “cold,” “very cold” and “extremely cold” events. Decreasing in frequency to the right of center are “hot,” “very hot” and “extremely hot” events.
Plotting bell curves for the 1980s, 1990s, and 2000s, the team noticed the entire curve shifted to the right, meaning that more hot events are the new normal. The curve also flattened and widened, indicating a wider range of variability. Specifically, an average of 75 percent of land area across Earth experienced summers in the “hot” category during the past decade, compared to only 33 percent during the 1951 to 1980 base period. Widening of the curve also led to the designation of the new category of outlier events labeled “extremely hot,” which were almost nonexistent in the base period.
Hansen says this summer is shaping up to fall into the new extreme category. “Such anomalies were infrequent in the climate prior to the warming of the past 30 years, so statistics let us say with a high degree of confidence that we would not have had such an extreme anomaly this summer in the absence of global warming,” he says.
Other regions around the world also have felt the heat of global warming, according to the study. Global maps of temperature anomalies show that heat waves in Texas, Oklahoma and Mexico in 2011, and in the Middle East, Western Asia and Eastern Europe in 2010 fall into the new “extremely hot” category.
…We’re not liable to come to any agreement on this, are we?
Sam Yates;
As to the CET record–well, it’s valuable, no doubt about that, but it’s LOCAL. Just as the US is local..
>>>>>>>>>>>>>>>>>>>>>
There you go again. What I said was that US and CET and OTHER temp records from ALL OVER THE WORLD give the same answer.
dropping thread, this is going no where.
davidnhoffer:
The posts of Sam Yates here and that of Eric Grimsrud on the ‘Inhofe thread’ are similar. Indeed, Perlwitz recently tried to adopt the method in an Open thread.
The technique is clear;
(a) make an untrue assertion
(b) ignore or misquote any rebuttals
(c) snow the thread with additional untrue assertions
(d) throw insults and ad homs. at those who rebut the untrue assertions.
I am wondering if a new directive has been circulated from the Al Gore propaganda school.
Richard
Hansen (and colleagues) writes about the “tails” – contain extremes.
There is no, however, in his references: Ruff and Neelin (2012), Long tails in regional surface temperature probability distributions with implications for extremes under global warming (http://www.agu.org/pubs/crossref/2012/2011GL050610.shtml) with interesting conclusion: “Surface temperature distributions with long tails have a much smaller change in threshold exceedances (smaller increases for high-side and smaller decreases for low-side exceedances relative to exceedances in current climate) under a given warming than do near-Gaussian distributions. This implies that models used to estimate changes in extreme event occurrences due to global warming should be verified regionally for accuracy of simulations of probability distribution tails.”
Hansen (and coauthors) writes: “We calculate seasonal-mean temperature anomalies relative to average temperature in the base period 1951-1980. This is an appropriate base period because global temperature was relatively stable…”
Should be (again) recalled: years 1951-1980 – this is only the negative phase of PDO (currently it is positive), it was “a passage” from positive to negative phase of the AMO (1981 – minimum) – at present is “the reverse”. Oscillations of the NAO and AO (such as ENSO) – were also other phases (than today). The differences for “oscillatory conditions” for 1951 to 1980 – present period – are obvious.
Nielsen-Gammon writes about it (http://blog.chron.com/climateabyss/2011/09/texas-drought-and-global-warming/) so: “So at present, both the PDO and AMO are properly configured to produce droughts in Texas, and this fact explains the current cluster of droughts.” “…Texas would probably have broken the all-time record for summer temperatures this year even without global warming.”
Dr. Hansen: “For example, an unusual atmospheric “blocking” situation resulted in a long-lived high pressure anomaly in the Moscow region in 2010, and a strong La Niña in 2011 may have contributed to the heat and drought situation in the southern United States and Mexico. However, such meteorological patterns are not new and thus as an “explanation” fail to account for the huge increase in the area covered by extreme positive temperature anomalies.”
But if – for La Niña – add the current oscillations “conditions” – AMO, PDO, ENSO, etc. …
In Europe, all the recent heat waves (2003, 6, 10) were perfectly configured with the rapid start of La Nina (and again, let us add, for example, the positive phase of the AMO …).
Blockade weather. The references Hansen paper, there is no paper Francis and Vavrus (2012), Evidence linking Arctic amplification to extreme weather in mid-latitudes (http://www.deas.harvard.edu/climate/seminars/pdfs/FrancisVavrus2012.pdf) showing the influence of AA on strengthening the blockades (“weakening” of the jet stream) – extremes of weather.
… and me – by the way jet stream – recall such reports:
Dispatch from AGU: An equable climate curveball [“equable climate problem”]
http://blog.chron.com/climateabyss/2011/12/dispatch-from-agu-an-equable-climate-curveball/
“… 6,000 years ago and the last interglacial period 125,000 years ago. Both periods are thought to be warmer than the present-day climate.”
“So in both seasons, the detectable segment of the pole-to-equator temperature difference was smaller than at present, and at high latitudes the seasons were less dramatic than at present.”
“What could cause such a thing? The answer probably lies either in the position and latitudes of the jet stream (Davis’s idea) …”
NASA in „The Impact of Climate Change on Natural Disasters” (http://earthobservatory.nasa.gov/Features/RisingCost/rising_cost5.php), – about “equable climate problem”: “As a result, global warming may cause the temperature difference between the poles and the equator to decrease. and as the difference decreases, so should the number of storms, says George Tselioudis, a research scientist at NASA Goddard Institute for Space Studies (GISS) and Columbia University.” “If we are creating an atmosphere more loaded with humidity, any storm that does develop has greater potential to develop into an intense storm,” says Tselioudis.”
However …: “We designed the computer simulations to show that as the ocean temperature increased, hurricanes would form more rapidly and easily, even in the presence of wind shear,” says Nolan, associate professor of Meteorology at the Rosenstiel School. “Instead, we got exactly the opposite result. As the water temperature increased, the effectiveness of the wind shear in suppressing hurricane formation actually became greater.” (http://www.sciencedaily.com/releases/2008/08/080812160615.htm)
The physicist Wolfgang Pauli was known for his often less than polite criticism of the work of some of his colleagues. He would sometimes exclaim “wrong” (falsch) or “completely wrong” (ganz falsch) when he disagreed with someone. Near the end of his life when asked his opinion of an article by a young physicist, he sadly said “it is not even wrong” (Das ist nicht einmal falsch). The phrase “not even wrong” is a popular one among physicists, and carries two different connotations, both of which Pauli likely had in mind. A theory can be “not even wrong” because it is so incomplete and ill-defined that it can’t be used to make firm predictions whose failure would show it to be wrong. This has also become the situation of “Man Made Global Warming/Climate-Change” theory from its beginnings to the present day. This sort of “not even wrong” is not necessarily a bad thing. Most new theoretical ideas begin in this state, and it can take quite a bit of work before their implications are well enough understood for researchers to be able to tell whether the idea is right or wrong. But there is a second connotation of “not even wrong”: “Something worse than a wrong idea”, and in this form the phrase often gets used as a generic term of abuse. In the case of anthropogenic climate change theory, the way some scientists are abandoning fundamental scientific principals rather that admit a theory is not supported by facts is something of this kind: worse than being wrong is to refuse to admit it when one is wrong. If you “follow the (research) money”, it leads to the political – which equates with power, raw power. By the way: “Cap’n Trade” is only a smiley face mask put on by “Cap’n Tax”. (Think Jack Sparrow and Black Beard, respectively.) You also might wish to read “Unstoppable Global Warming (Every 1,500 Years)” 2nd edition.
P.S.: The major selling point of Hydrogen Powered vehicles is? They only emit water vapor! And where do they operate? On concrete or asphalt covered surfaces, acting as heat sinks that create updrafts that send the vapor skyward into the atmosphere, thereby contributing to a further “Warming” of the planet! (If the alarmists are right, that is.)
WOW! A lot of comments. Hansen has become a statistician and no longer practices good science. I think he should change the orbit of the Earth, its declination, and its wobble. This being done he should handle the sunspot issues, and the solar weather. Having accomplished this he can change the Earth’s cyclical behavior and therby the climate. Even this may no control weather which are daily, weekly, monthly type events. Moreover, Jimbo. stop giving us the concensus argument – science is not based on CONCENSUS. By the way , Jimbo, ever hear of historical geology – try the 1st year course.
I invite you to read my blog: http://energycrisis12.blogspot.com. My e-book – The Sky Will NOT Fall – Unmasking the Green Revolution – Amazon, Barnes & Noble. Forthcoming e-book – soon to be puiblished – Beyond Our Control – Debunking Manmade Global Warming.
[SNIP: Sorry, you were allowed one mention of your blog and e-book. Using Anthony’s blog to direct traffic to your blog is not very civil. Please don’t do it. -REP]
richardscourtney says:
August 9, 2012 at 12:00 am
“The technique is clear;
(a) make an untrue assertion
(b) ignore or misquote any rebuttals […]”
That is unfortunately drastically eased by currently WUWT not having coding to allow images to be shown in comments, an aspect which would be best to change. Usually, on any site, only several percent or less of readers will click on a link, but the argumentative tactic of being able to count on such collapses in event of images being harder to scroll past without seeing. Such as my prior post ends up at an order of magnitude less effectiveness because of critical images not being blatant.
For the Northern Hemisphere average, for 5 year means, the CAGW movement basically claims that there was only around 0.1 to 0.2 degrees Celsius temperature decline 1940s-1970s, followed by around 0.6 degrees warming 1980s-2000s. However, without their fudging of past temperature data, including skewing by adjustments predominately in the opposite direction of proper correction for UHI, the actual picture for such NH several-year averages is closer to around 0.3 degrees Celsius temperature decline 1940s-1970s, followed by around 0.3 to at most 0.4 degrees temperature rise 1980s-2000s, with the latter mainly just taking temperatures back to near the levels of the late 1930s.
In images, how the 1930s were about as warm as the 1990s is seen in http://earthobservatory.nasa.gov/Features/ArcticIce/Images/arctic_temp_trends_rt.gif
first for the arctic, and, secondly, for the average over the Northern Hemisphere as a whole when without dishonest revisionism of past temperature measurements, in http://www.real-science.com/wp-content/uploads/2012/04/ScreenHunter_296-Apr.-08-09.29.jpg
when combined with http://hidethedecline.eu/media/PERPLEX/fig75.jpg
Any net warming of the Northern Hemisphere mean in the 1990s-2000s compared to the 1930s drops to the level of hundredths of degrees at most, not even tenths of a degree. So much for grand global warming. (There was more major net global warming before the end of the 1930s, but the 19th century and the early 20th century were part of recovery from the Little Ice Age, while human emissions were many times less then than a century later, not supporting human effects being dominant).
Full non-fudged southern hemisphere temperature data is harder to acquire, but, beyond partial segments like http://hidethedecline.eu/media/PERPLEX/fig47.jpg , the overall global temperature average would be related to what global sea level data shows: slower rise rate in the second half of the 20th century than during the first half (“1.45 ± 0.34 mm/yr 1954–2003”
versus “2.03 ± 0.35 mm/yr 1904–1953” as http://www.agu.org/pubs/crossref/2007/2006GL028492.shtml notes).
The preceding is discussed with many more illustrations and references in
http://hidethedecline.eu/pages/posts/part1-the-perplexing-temperature-data-published-1974-84-and-recent-temperature-data-181.php
http://hidethedecline.eu/pages/posts/part2-the-perplexing-temperature-data-published-1974-84-and-recent-temperature-data-183.php
http://hidethedecline.eu/pages/posts/part3-the-perplexing-temperature-data-published-1974-84-and-recent-temperature-data-184.php
http://hidethedecline.eu/pages/posts/part4-the-perplexing-temperature-data-published-1974-84-and-recent-temperature-data-185.php
and
http://www.real-science.com/hansens-tremendous-data-tampering
and
http://wattsupwiththat.com/2010/03/16/rewriting-the-decline/
http://wattsupwiththat.com/2010/03/18/weather-balloon-data-backs-up-missing-decline-found-in-old-magazine/
among others.
(The last two, like the others, are good articles, but WUWT has never directly shown many people the biggest picture seen by such as http://www.real-science.com/wp-content/uploads/2012/04/ScreenHunter_296-Apr.-08-09.29.jpg and http://hidethedecline.eu/media/PERPLEX/fig75.jpg in combination together at once, so people can see what happens when both of those Big Lie techniques are removed simultaneously instead of discussing one at a time separately; if I’m lucky, perhaps several people may click on these links, but major articles get thousands of times the views).
Double-checking now, surprisingly real-science.com breaks on external linking, but the 1975 National Academy of Sciences graph is also viewable at http://img111.imagevenue.com/img.php?image=43034_ScreenHunter_296_Apr._08_09.29_122_441lo.jpg
Such in combination with http://hidethedecline.eu/media/PERPLEX/fig75.jpg for later decades illustrates the real picture of 1990s-2000s temperatures simply being comparable to the warmth in the 1930s.
I am amazed that Martin Lack would complain about the moderator on Watts Up With That. I had first encountered him while engaging in a debate on Climate Denial Crock of the Week with Peter Sinclair
“Duluth Storm: Yet Another Postcard from the Future”
June 25, 2012
http://climatecrocks.com/2012/06/25/duluth-storm-yet-another-postcard-from-the-future/
http://climatecrocks.com/2012/06/04/post-flood-midwest-farms-a-wasteland-deniers-they-need-more-co2/comment-page-1/#comment-10630
Now for how one is treated on his blog and to think that he is shameless enough to complain on Anthony’s site is deplorable.
The Yellow River basin in China – Part 4
http://lackofenvironment.wordpress.com/2012/06/15/the-yellow-river-basin-in-china-part-4/
i>Sam Yates says:
Not at all; in the paper they also show the effects of using 1981-2010 as their base period, and although the widening of the bell curve is not quite as visible, the shifting of its midpoint (and the increased incidence of extremes of temperature) is still clearly apparent.
The point is, they didn’t show the effect of properly quantifying the variability of the temp record over a climatologically appropriate period. The years following 1980 are important to that – the fifty before 1950 much more so. As Pat points out, they are not operating from a quantified theory of natural climate variability. They are intentionally restricting the assessment of variability to a period that they admit they chose because it does not vary. The technical term for this is “chutzpah”. It’s the kind of thing you do when you don’t have to worry about peer review, which these PNAS vanity papers are not subject to.
The focus of the paper is whether or not people nowadays should be able to recognize climate change based solely on their own observations, and the paper is entitled “Perception of Climate Change.”
Absolute nonsense.
Obviously, individuals cannot directly perceive the global temperature field. That is why we create monitoring networks, spend billions lofting weather satellites, and subject the data from those billions of sensor readings to all manner of descriptive statistical analyses and ‘adjustments’ – legitimate or otherwise.
The focus of this ‘paper’ is not an assessment of perception or any other science. It is a propaganda piece, whose focus is manipulating that perception thru the deception of convincing people that they :should be able to directly perceive the global temperature field, and they should feel stupid to admit that they cannot. The principle involved is not a question of science, it is “The Emperor’s New Clothes” being acted out for political effect.
I’m afraid I don’t quite follow. What conclusion are they assuming? He’s quite correct to note that the temperatures during the period from 1951-1980 are within the Holocene range; surely that’s not controversial. And that climate IS what we’re adapted for, since it’s the only one that humanity has experienced. Would you mind elaborating on this a bit?
Accompanied by the following assertion that the last 20 years are not consistent with the Holocene. Assumes the conclusion that he is trying to get people to “perceive”. That is how propaganda works.
Where Vikings did or did not live in the past is utterly irrelevant.
Uh, no it is not. The claim is that ice melt demonstrates that the temps of the last 20 years are out of bounds for thousands and thousands of years. But that ice melt is currently exposing previously buried Viking settlements, demonstrating that around one of those thousands of years ago, there was much more ice than during his ‘base period’.
Greenland covers approximately 0.4% of Earth’s surface, which is easily small enough for it to have been, in the past, as warm or even warmer than now without having any real effect on global temperatures. The modern period is unique due to the global nature of the current rapid temperature change, in contrast to the rapid regional and glacially (if you’ll excuse the adverb) slow global changes that occurred in the past.
LOL OK, that is another good reason why Hansen’s appeal to Greenland ice melt as proof of ‘global warming’ is illegitimate. Got any more?
Um…No it isn’t: http://www.cmar.csiro.au/sealevel/sl_hist_few_hundred.html
Um … yeah it is: http://www.cmar.csiro.au/sealevel/sl_hist_few_hundred.html
You have yet to demonstrate that it IS an example of cherry picking.
Yeah, we have.
He has a point that using the same reference period makes comparisons easier, and as he showed in the paper itself, using a different, more variable period (1981-2010) does not dramatically affect the results.
Not shown in the paper: the much more variable period 1900-2010. Properly quantifying the natural variability of the climate system to pull out from that the ‘global warming’ that he wants to convince people they are seeing would necessarily entail longer periods than 30 years (look again at PDO, AMO, etc for their periodicity, and consider the effects of that on quantification of variance and presentations of “extreme” values). It would also entail including the warm 1930’s AND detrending to remove the natural trend clearly evident pre 1950, and they do NOT want to do that.
This ‘paper’ of Hansen’s is a propaganda piece. Period. It is nothing more than an elaborate version of NCDC’s shoddy ‘probability’ talking point released a couple of weeks ago. Conflates ‘warm’ with ‘warming’. Equivocates on the term ‘global warming’ between natural and (alleged) anthropogenic sources. Etc. Etc. Etc.
Half the time, these clowns are doing “science by press release” and the rest is “press release by scientific paper”. We need to fire the propagandists and replace them with actual scientists.
RTWT. Anthony:
South America and Australia are, rumor has it, in the SH.
Side note: South Africa had snow in all 9 provinces this winter for the first time on record.
I will spare you the full script of the little skit of the conversation between the Physicist and Climatologist–but briefly, after a brief exposition of the nature of energy flows, the Physicist responds to each of the theories and projections and examples of the climatologist with “See the above”. Until the final objection, in which the climatologist cites the hundreds of billions of dollars available for (pro-)AGW research. The Physicist, realizing he need only play the game to get his funding dreams fulfilled, now offers, under the new rubric of Climatologist #2, to explain to the reader why AGW is important and excellent science.
Do Muller and Mosher come to mind? Understandable.
WOW! Statisticians world-wide are howling in outrage at your gratuitous insult.
I hope your editor can spell better than you. The c’s and s’s in that word are not evenly divided. I leave it to your research abilities to determine which should be cut back, and which increased.