Newly found weather records show 1930's as being far worse than the present for extreme weather

Plot of NOAA/NCDC state high temperature records by decade with atmospheric CO2 concentration overlaid. From C3 Headlines with thanks – click to visit website

The Heat Was On—Before Urbanization and Greenhouse Gases

By Patrick Michaels on World Climate Report

Sure is hot out! And what better time for a paper to appear in the Journal of Applied Meteorology and Climatology describing the construction of the “all-time” records for various types of weather extremes for each of the 50 United States plus Puerto Rico and the U.S. Virgin Islands. The paper details efforts of the U.S. State Climate Extremes Committee (SCEC) established by the National Climatic Data Center (NCDC) and led by Dr. Karsten Shein. Basically, the SCEC dusted off old records and found other new sources. So now we have “new and improved” data (available here) for the value, the date and the location of the all-time high and low temperature, greatest 24-hr precipitation, greatest 24-hr snowfall and greatest snowdepth for 50 states and two territories. The statewide record extremes have been updated through 2011 and are subject to continuous updating.

This paper is an interesting read for those who perseverate on climate history and how it is constructed from a variety of observations both made from “official” (federal) observing stations as well as those deemed reliable from “non-official” observations (such as 12-oz soda bottles or credible “amateur” observer accounts). The new effort resulted in “the revision of 40 percent of the values” contained in the old dataset at NCDC and “underscored both the necessity of manual quality assurance methods as well as the importance of continued climate monitoring and data rescue activities to ensure that potential record values are not overlooked.”

It also is useful for putting the recent heat wave in perspective. Despite the 24/7 caterwauling, only two new state records—South Carolina and Georgia—are currently under investigation. And, looking carefully at Shein et al. dataset, there appears to be a remarkable lack of all-time records in recent years.

This is particularly striking given the increasing urbanization of the U.S. and the consequent “non climatic” warming that creeps into previously pristine records. Everything else being equal—and with no warming from increased greenhouse gases—most statewide records should be in or near big cities. But they aren’t.

This year there were a huge number (many thousands) of reports of daily high temperature records being set across the eastern two-thirds of the country in recent weeks, and even a large number (a few hundred) reports of all-time records high temperatures being set for a particular location. But if only two new statewide records were set, that’s hardly an historic heat wave when considered in its totality.

In Table 1, below, we list the all-time record daily maximum temperature observed in each of the 52 entries (as compiled by the SCEC) and the date and location where it was recorded. Notice that the vast majority of the all-time records were set more than half a century ago and that there are exceedingly few records set within the past few decades. This is not the picture that you would expect if global warming from greenhouse gas emissions were the dominant forcing of the characteristics of our daily weather. Instead, natural variability is still holding a strong hand.

Table 1. All-time statewide maximum temperatures (from NCDC)

In Table 2, we’ve compiled the top five years when the most records were set. When multiple years tie for the high, each individual year gets a fraction of a “record”. So, for example, 1954 and 1933 each get a half of a record for Colorado.

Table 2.

But this doesn’t stop people from implying that last week’s heat wave as an indication that global warming is leading to unprecedented conditions.

Capital Weather Gang (CWG)—the popular and respected weather blog for conditions in and around Washington DC, and one which is closely watched by the media, was quite vocal all about all-time records of one sort or another being set in our Nation’s Capital during last week’s heat wave.

If the Shein et al. methodology is applied to DC’s temperatures, then CWG’s very public pronouncements (they were picked up on the Drudge Report) are not all going to stand. That’s because CWG relied only on a single record, while largely ignoring the comprehensive set of observations historically taken within the geographical boundaries of the District of Columbia. The single record used by CWG is the “official” version of the Washington DC daily temperature which is a record which has been stitched together from observations made at National Airport (from 1945 through the present), which by the way is not even in the District of Columbia, and from observations taken at a Weather Bureau location at 24th and M street (1889 through 1944, and other locations prior to then). But when the records were concurrent (which they were during the 1940s and 1950s), only one is included (DCA).

If you really wanted to establish all-time records for Washington DC, you’d have to consider all available records that are credible—rather than relying on a data for a single “station.”

That’s what Shein et al. did. Although the SCEC has not yet compiled the all-time weather records for Washington DC, the word is that they are in the process of doing so, and are considering all available observations.

The CWG should do the same when discussing records for “Washington DC”. Or at the very least, they must be very clear that they are discussing a single (changing) location (i.e., Reagan National Airport, the downtown City Office, etc.) rather than Washington DC as a whole.

Here is an example of how things can go awry.

According to CWG, the recent heat wave “Washington D.C.” tied its record for the longest string of consecutive days in which the daily high temperature was 100°F or above. According to the CWG, the record was/is 4 days set in 1930 and 2012. However, in July/August 1953, 5 days in a row with temperatures of 100+°F were observed at the old Weather Bureau observing station at the City Office. These observations were from “an” official weather station within DC but not part of “the” “official” stitched together record. If the NCDC SCEC were compiling all-time strings of consecutive days of 100+°F, they most certainly would consider the old City Office records (including during the time of overlap with DCA observations), something that the Capital Weather Gang opted not to do.

Whether or not additional examination would alter any of the other “all-time” temperature that the Capital Weather Gang identified as being broken in “Washington DC” during the recent heat wave is unknown at this time.

One lesson here is that when considering “all-time” extreme weather records for a particular region, a comprehensive study must be undertaken (as described by Shein et al.) rather than simply deferring to a single station record.

The other take-home is that one has to be very careful about attributing the recent extreme temperatures to dreaded global warming. As noted above, there are surprisingly few all-time state records in recent years. Further, a look at their table indicates that only one of these—Providence RI, in 1975—comes from a city. Somehow—and this seems impossible—the dreaded greenhouse effect cannot raise already climbing urban temperatures to state record levels.

We can thank the SCEC for helping to do most of the dirty work in establishing an accurate dataset of all-time statewide record extremes for the United States that can be relied upon into the future, so that accurate assessments can be made when comparing current extreme weather events to past ones.

Reference:

Shein, K., D. Todey, F. Akyuz, J. Angel, T. Kearns, and J. Zdrojewski, 2012. Evaluating Statewide Climate Extremes for the United States. Journal of Applied Meteorology and Climatology, doi:10.1175/JAMC-D-11-0226.1, in press.

 

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John A

per·sev·er·ate
Verb:
Repeat or prolong an action, thought, or utterance after the stimulus that prompted it has ceased.

I had to look it up.
The rest of Pat Michael’s report doesn’t surprise me in the least.

TinyCO2

Nice:-) Great to see that there are people still doing a good job.
How many articles do we see where some journalist solemnly proclaims that some weather event or other is at an all time high due to climate change? The easiest way to illustrate the proof is with a graph, a picture painting a thousand words and all that, but how often does it happen? Apart from arctic ice and global temperatures can anyone think of a warmist graph?
Sceptics need to have a slogan ‘SHOW US YER GRAPH!’

D Caldwell

Yes, yes, all of this is mildly interesting, but highly premature until the older records have undergone the proper “adjustments”.

R. Shearer

Even with a lower population, about a half million people were forced to leave the Dust Bowl states then.

If July 1936 happened this year… To quote Bart Simpson…. so many folks in the climate science community would ‘have a cow’.
I suspect that the retort is that the 1930s was an event brought on by natural variability with the confluence of xyz variables which all translate into warming forcings and feedbacks– WHILE 2012 is one where just about every single ‘natural variability’ indicator would point to us being in the ice box, were it not now for AGW … and then further posit that if 1936’s “natural” conditions were to occur in the futre along with our present-tracked AGW component, well, we may not survive it.

Rex

I would have thought that heat waves might contribute to an increase
in mean temperatures. Others seem to want to put the cart before the
horse … Beats me.

mogamboguru

Well, is it just my eyeball Mark I seeing a flat, if not declining trend in the plot of NOAA/NCDC state high temperature records, or do you see the same trend as I do?

mike g

Classic confirmatin bias on a massive scale is the only explanation these records hadn’t been surfaced by any of the thousands of main stream “scientists” involved in the AGW fraud. What do you expect with activists, not scientists, running all the major societies.

Conditions in the N. Atlantic 1n the early 20th century were comparatively different to the late 20th and early 21st. This is clearly demonstrated by the CET (N. Atlantic is the main driver) when the summer – winter temperatures were running in the anti-phase.
http://www.vukcevic.talktalk.net/CETseasons.htm
If USA temperatures were equally affected it is not known to me.

fredb

I think the issue is that the recent events are records *on top of* the earlier records.

pat

Were the records found in Hansen’s garage?

Bryan A

Most certainly these records from the SCEC will be altered at some point. We are all aware of how current Global Warming causes prior temperature records to be adjusted downwards

Claims of drought seem overblown.
3 states have set a monthly record for driest month in the last 12 months.
Colorado Mar 2012, Delaware Feb 2012, Wyoming Jun 2012.
http://sunshinehours.wordpress.com/2012/07/12/2012-isnt-that-dry-so-far-noaa-precipitation-data-by-state/
6 states have set a monthly record for wettest month in the last 12 months.
Florida June 2012, NH Aug 2011,NJ Aug 2011,NY Aug 2011, Pennsylvania Sep 2011, Vermont Aug 2011
http://sunshinehours.wordpress.com/2012/07/14/wettest-month-noaa-data-surprise-not-as-dry-as-they-claim/

Gary Pearse

In Figure 1, note that the 1930s decade couldn’t be “adjusted” enough to prevent the perturbation of the otherwise “perfect” temp/CO2 fit. I now see what a Herculean effort Hansen et al made to squash the 1930s temps down – they had to go well beyond the limits of decency in their quest. I was a 30s baby but just missed 36 by 2 years. That decade was a topic of conversation in the parlours (we don’t have parlours in houses anymore – no kids allowed, for visitors like the preacher, etc.) of the continent throughout the 40s and when the dust storms came back in the fifties (I grew up in Winnipeg-flat prairie) I got to see what I had missed in the middle 30s – brown air, orangy-yellow sunlight, handkerchiefs over the nose, black/brown sweat-mud inside collars and cuffs, black snot, and tiny barchans of topsoil around the leaside of telephone poles, fence pickets and house corners.
Well this extended the parlour talks of the dirty 30s for another few years – but winters had turned cold in the late 40s. I had a paper route and my mother used to walk with me in a January evening to collect for the newspapers – fearing that I might be overcome on my long walk in the dark cold from Portage Avenue – an east-west main streat on out of town to my last customer – a dairy farmer.. For her effort, I treated her to a movie – at night the fare was adult black and white silver screen stuff with Bogey, Edward G. Robinson, Barbara Stanwick, and the like – 12 cents each – a fortune compared to the Saturday afternoon “Horse Operas” with Roy Rogers, Rod Cameron, Hoppy,… at 5 cents.
Definitely, there has been a cherry-picking industry at work to hide this weather history..

Gunga Din

I had commented on other post how list I had from 2007 differed from list from 2009 and 2012. (I’d even put up a couple of the whole lists. They may have been more annoying than informative. 😎
I certainly hope that the differences were due to things being actually corrected rather than “adjusted”.
PS The biggest was lowering the record high, set on the for the same day in the same year in the late 1800’s by 5*F. The very latest list raises it back up to the 2007 temperature.

Gunga Din

Another PS. Here’s where I obtained the list on different years. http://www.erh.noaa.gov/iln/cmhrec.htm

usurbrain

10 years ago, when I was trying to decide if I should get a heat pump, I did several searches of the average heating days per month/day for my city and for areas where I had good, solid, data on the kWhr usage per day for heat pump usage. I found quite a few of these historical records and many went all the way back to the 30’s and even earlier. There were many daily accumulative tables of the heating degree days (HDD). A few years ago I had a brain storm that if it was getting warmer then the daily HDD would show this. I have spent many hours over the last few years trying to find this data again. It is not there. It has been removed. There are some that go back 10 years, and some that go back 20-25 years, depending on the city you look for and who is keeping it, but I can’t find the old NOAA tables that had the “ancient” history of these numbers. Where did they go? Why did they remove this information? Where is it? What are they hiding? Are they trying to revise history again?
Second question. Why is it that when you read a thermometer, by sight, that you always visually round it to the closest whole digit or in some cases will indicate 1/2. But, when you convert from Celsius to Fahrenheit, the decimal is carried out to two(+) places? Surely this has some effect upon the historical temperature reading. This would be further exacerbated by the fact that when it is cold out you unconsciously tend to see a colder temperature and when it is hot you see a hotter temperature.

son of mulder

UHI was wrong all along should have been UCI judging by these records;>)

David Ball

There is a case of “the mysterious trapper” in Canada. He was chased by authorities through what was thought to be an impassable mountain trail after shooting a constable. It is interesting that this occurred in 1934.

Lol, I’m deja vousing all over again! Can we get a retroactive “amen” for Steve, Joe, and Anthony? http://wattsupwiththat.com/2012/07/08/why-the-u-s-east-coast-heatwave-was-not-unusual-nor-the-number-of-record-temperatures-unprecedented/

Dave Worley

I’ve seen articles that blame the dust bowl on farmers’ unsustainable practices.
Studies which blame globlal warming for environmental issues come from scientists who fail to find a cause, or a remedy, for a local environmental issue, They take the easy way out, blaming the catch all “Global Warming” and in their minds they turn failure into success….and press! They might as well be blaming God, but then they are probably secular humanists, so that option is out.
If they were honest scientists, they would admit that they cannot find a specific cause or remedy (for instance where oyster yields are down in Oregon). Instead they just piggy-back on the latest global catch phrase and act as though their research is relevant……and worthy of additional funding.

Bill McKibben (350.org) is constantly sending out doom and gloom, hot weather Tweets.
Here’s my Tweet back at him today:
@billmckibben It’s hot in Gotham City too… http://t.co/6GBtVuNt

davidmhoffer

pat says:
July 14, 2012 at 1:16 pm
Were the records found in Hansen’s garage?
>>>>>>>>>>>
Wrapped in discarded tree ring data and marked “secret”.

Mindert Eiting

All-time records are peculiar statistics because they amount to severe dependency of the data: each record redefines the records thereafter. Am I the only one who cannot make sense of the graphs and tables?

Ian H

The interesting thing about the 1930s in my opinion is that they still lack a decent explanation. Warmists are too busy trying to revise history so that it never happened. Sceptics are often too busy celebrating the fact that it was warmer back then and seldom go beyond that. Nobody seems to have much interest in explaining WHY it was so warm back then and why it shopped being so warm shortly thereafter.

Richard Keen

NCDC seems to have downscaled the Colorado max from the 1888 record of 118 at Bennett to a couple of more recent 114 degree readings (which may have been tied this year). Our state climatologist effectively discredited that old 118 reading some years ago, so the change is warranted – even though it might add a heat record (or tied record) to the current decade.

I don’t see the 1930’s spate of USA entire-state alltime record highs, or the lack
of these since the 1990’s, being proof that AGW does not exist at all. Have a
look at the UAH lower troposphere global temperature anomaly index, and see
that since 1979 the world has *warmed*, in part from natural cycles such as AMO.
The 1930’s spate of records appears to me in part caused by farming practices
that were a significant cause of the “dust bowl”.
One effect that I see of global warming – whether by AMO/PDO or by CO2 –
extratropical weather, especially in the northern hemisphere, getting milder.
Extratropical weather events of scale that show up on weather maps are
largely caused by horizontal temperature gradients. The Arctic has warmed
more than the tropics – and the models predicted that item.
So, I expect extratropical windstorms and temperature swings to get milder.
The record shows a slight decreasing trend since 1950 of tornadoes in USA of
strength F2 or more. The Blizzard of 1888 and no extratropical storms since
then caused record low tides in Washington DC’s tidal waters, and probably a
few snowfall records farther north that still stand.
There is the matter that about 40% of reported post-1973 global warming
(as reported via HadCRUT3) appears to me caused by a set of periodic
natural cycles. And also, it appears to me that about 20% of the warming
caused by increase of greenhouse gases appears to me caused by ones
other than CO2, and whose increase was largely stopped in the 1990’s.

cui bono

Dear sweltering folks across the pond,
“24/7 caterwauling” from the doomsayers? In 1988 this whole thing started as a result of ‘partial US Summer heatwave alarmism’; got promoted to ‘global warming’; got rebranded as ‘global climate change’, and has now slunk back to its parochial roots.
It’s been said so many times in the last few weeks, but American AGW alarmists have no idea how absurd they currently sound to those of us in the outside world. Or indeed to anyone outside the little blob of red over part of the US.
Travel more! Come and join those of us who will be shivering and drowning during the London Olympics! Watch with merriment as the Olympic Torch gets put out for the hundredth time by the rain!
Yours faithfully,
The unaffected 99% of the planet.

James McCauley

Speaking of old data I thought you would all get a kick from this recollection of my mother’s yesterday. She assertively wrote this “good ‘ole days” (1936 +/-1yr) anecdote for me to pass on to WUWT:
“Dear Mr. Watts,
My son Paul and I have been discussing the recent heat wave and I was going back recalling some of my childhood days, some 75 years ago. Our home in Cleveland, Ohio was on a corner lot. I can remember when, in the very hot summer afternoons, the intersection in the center of the streets would blow up at least two times each summer and had to be replaced by the street pavers. The street was of bricks and the whole center of it left quite a mess. Fortunately, no one was hurt from flying bricks. Then, when the intersection was re-laid we had fun chewing the new cooled black tar which surrounded the perimeter (of the intersection).
(Her drawing of the intersection left out, unfortunately.)
So, this is my story and the heat and humidity this year has brought back another recall.”
Mom was 9 in 1936 and don’t tell her it’s hotter these days and she very much appreciates AC over ice blocks!
PLM

DaveS

Apparently the UK Met Office released a report this week that, according to Louise Gray in the Telegraph, ‘for the first time, attributed a number of severe weather events to climate change. The study concluded that the devastating heatwave in Texas last year was about 20 times more likely to have happened because of climate change rather than natural variation’. And supposedly ‘the second hottest (UK) November on record in 2011 was 60 times more likely than in the 1960s because of climate change’. Lengthy quotes follow from Peter Stott, including the inevitable ‘it will take much more research to know…’ and ‘Our vulnerability to extreme weather is much greater than it used to be.’
Sounds like a load of tosh to me, but has anyone seen this report?

Bill Illis

I’m surprised that the NCDC would put this out. It must mean that an independent steering committee was appointed to oversee this work and Tom Karl and Tom Peterson were kept out of it somehow.
Just look at the 1936 numbers. 4 records of 120F or 49C on different days in Oklahoma in the same year. What was “The Grapes of Wrath” about again?

davidmhoffer

Re: Dust Bowl and farming practices
No, it wasn’t the farming practices that caused the dust bowl. Yes, they made it worse, and yes, new farming practices such as leaving stubble to stand in the field instead of burning it off made things better. But the cause of the drought was likely natural. Captain John Palliser explored the Canadian prairie in (if memory serves) 1857 to 1860. He reported the entire region as arid, desert like, and unfit for human habitation. Happened before, and the conditions that caused it will most likely happen again. With better land management practices such as zero till, planting of wind breaks and erection of snow fences, hardier strains of grain, and yes, one of the biggest helping hands of all, more CO2, the next round of drought won’t be as hard on the local farmers as the dirty thirties was.

Justthinkin

I hate to be the bearer of bad news,but I have found a fatal flaw in Mr.Michaels’ work. His start point for these record temperatures obviously goes back WAY to far.We all know that no temperatures (recorded at least) existed prior to 1985 A.D. Who’s cherry picking and adjusting now??
(MOD squad….surely I don’t have to add the sarc tag?)

Ted

The wqrmists know this but must continue pushing the big hoax. How can they life a life of lies and deceit?

rogerknights

UzUrBrain says:
July 14, 2012 at 2:21 pm
10 years ago, when I was trying to decide if I should get a heat pump, I did several searches of the average heating days per month/day for my city and for areas where I had good, solid, data on the kWhr usage per day for heat pump usage. I found quite a few of these historical records and many went all the way back to the 30′s and even earlier. There were many daily accumulative tables of the heating degree days (HDD). A few years ago I had a brain storm that if it was getting warmer then the daily HDD would show this. I have spent many hours over the last few years trying to find this data again. It is not there. It has been removed. There are some that go back 10 years, and some that go back 20-25 years, depending on the city you look for and who is keeping it, but I can’t find the old NOAA tables that had the “ancient” history of these numbers. Where did they go? Why did they remove this information? Where is it? What are they hiding? Are they trying to revise history again?

Two or three years ago there were a few similar posts to this one here one WUWT, one by me. If there were any sort of well-organized, well-funded machine behind us, its opposition research investigators would have got on the scent pronto. Instead, this valuable lead has languished.
How about it, Heartland? It wouldn’t cost much, and the potential payoff in public perception would be high if it turned out there had been an effort to dump these records down the memory hole. That’s something “you don’t need a weatherman” to understand.

davidmhoffer

Ted says:
July 14, 2012 at 5:17 pm
The wqrmists know this but must continue pushing the big hoax. How can they life a life of lies and deceit?
>>>>>>>>>>>
$ conquers ethics.

Skiphil

The answer is clear: just let Jim Hansen and friends “adjust” the data until the correct answers are given…. /sarcasm

clipe
Jimbo

We must get rid of the 1930s warm period. Get ready for new graphs showing the 1930s like the Little Ice Age.

Ed Barbar

Does anyone actually believe any of these high temperatures are actual “records” in the sense they are the highest ever? Of course not. They are only the highest in recorded history. There’s a little bit of arrogance about man thinking once he got around, the world began.
That having been said, records will be more easily “broken” when measurements start, and then it will become increasingly difficult. Breaking “records,” may show an unusual trend, or not.
It’s a waste of time.

Everything else being equal—and with no warming from increased greenhouse gases—most statewide records should be in or near big cities.
I don’t think this is right. Urban areas have their biggest effect on nighttime temperatures, and on an exceptionally dry, hot day the tendency for urban areas to have watered lawns and shrubbery tends to keep the temperature down a bit compared to the surrounding baking countryside. Right downtown where concrete defeats lawns I’d expect exceptionally high temperatures, but that’s not where most of the urban thermometers are.
In the 2011 Texas drought, for example, Dallas Love Field had some of the hottest nights anywhere, but wasn’t in the running for hottest days.

KevinM

I’m not a warmer, but these repeat posts with the same flawed analysis makes me wonder if I picked some other form of wrong side.
No Miendert Eiting, you are not alone.

David

Mindert Eiting says:
July 14, 2012 at 3:54 pm
All-time records are peculiar statistics because they amount to severe dependency of the data: each record redefines the records thereafter. Am I the only one who cannot make sense of the graphs and tables?
======================================
What is the trouble? An all time record is just that, the hottest recorded. Here is a different way of looking at the data…From Steve Goddard…
” There are 901 USHCN stations which were operating during both 1930 and 2011. Out of those stations, eighty-nine percent set their all time July 14 maximum temperature record with CO2 below 350 ppm.
Thirty-eight percent (347) set their all time July 14 record during the 1930s and eighteen percent (162) set their all-time July 14 record during the 1950s.
Only three stations have set their all time July 14 record during the current decade.
http://stevengoddard.wordpress.com/2012/07/14/89-of-us-july-14-high-temperature-records-were-set-below-350-ppm-co2/

Peter Jones

My daughter just finished 7th Grade and one of the books for them to read was “To Kill A Mockingbird.”
I had ordered the DVD for her to watch after she finished, and the first line of the movie says it all. The movie is set in 1932 in Maycomb, Alabama.
From the script, this is the start of the movie as they fade in on the sleepy town:
“Maycomb was a tired, old town,
even in 1932 when I first knew it.
Somehow it was hotter then.”

Eric (skeptic)

John N-G pointed out correctly above that the urban areas often don’t compete with rural areas for hottest high temps due to cooling factors such as irrigated lawns. But then he gave this example:
“In the 2011 Texas drought, for example, Dallas Love Field had some of the hottest nights anywhere, but wasn’t in the running for hottest days”
Love Field is nothing more than an a heat sink. It is a giant area of concrete, not very dark colored and heat absorbing, but it is heat retaining. We would expect both lower highs and higher lows there, all other things being equal. I doubt that nearby irrigation has much of an effect. I have often pointed out that Reagan National has some higher lows due to gravel around the thermometer. It was the subject of a post here a few years ago (incorrectly id’d as asphalt) but has doubled in size since. My observations are that it raises nighttime lows on clear calm nights.

Mindert Eiting

David asks what is the trouble. I want to be constructive: standardize all weather variables for the considered period, producing z-scores. Report for each year the sum of squared z-scores. Like sport-statistics these weather records are nice stuff but, as other readers also pointed out, they cannot be used in a meaningful analysis. Just some remarks by a skeptic.

Caleb

RE: morebrocato says:
July 14, 2012 at 12:22 pm
“…I suspect that the retort is …….. 2012 is one where just about every single ‘natural variability’ indicator would point to us being in the ice box, were it not now for AGW … ”
You are correct. I have already heard this retort during quite a number of conversations, here and elsewhere. (It can be annoying, especially when the same people who said the sun had no effect now say Global Warming is negating the “quiet” sun’s cooling effect…..but never mind that.)
However a problem with this retort is that one “natural variable” is a sixty-year-cycle, and according to that we were suppose to return to Dust Bowl conditions (and have severe 1938-like East-coast hurricanes) starting back in the 1990’s.
Instead it is cooler.
The only way around the fact we have not returned to the heat of the 1930’s is to ignore how hot it was back then, and to exaggerate how hot it is now. And that is exactly what I see some doing.

michael hart

How is any statistical bias based on the number of observations dealt with? If no observations are made at all, then no ‘records’ of any kind could be broken. Conversely, if a ‘record’ of any kind does occur, then a large number of stations/thermometers is more likely to capture that data.
I would guess that in modern times there might be more observations made, even if this is due to simply having a larger population. Is this the case?

This is particularly striking given the increasing urbanization of the U.S. and the consequent “non climatic” warming that creeps into previously pristine records. Everything else being equal—and with no warming from increased greenhouse gases—most statewide records should be in or near big cities. But they aren’t.
Up to the 1950s, aerosol levels were much higher in cities than rural areas. These aerosols and aerosol seeded clouds reduced solar insolation and this would be most marked on otherwise cloudless days, ie days that are cloudless in rural locations. These cloudless days are also the days on which very high temperatures are recorded. This is the reason few record high temperatures were set in cities before the 1950s.
After the 1950s, aerosol levels began to decline. A trend that accelerated in the 1970s when vehicle aerosol emissions were sharply reduced. As aerosol levels declined, solar insolation increased, resulting in higher temperatures.
Thus, the post 1970s warming was largely caused by decreasing urban aerosol levels combined with an increasing urbanization bias (including an airports bias) in the surface temperature datasets.

Kelvin Vaughan

UzUrBrain says:
July 14, 2012 at 2:21 pm
Why is it that when you read a thermometer, by sight, that you always visually round it to the closest whole digit or in some cases will indicate 1/2. But, when you convert from Celsius to Fahrenheit, the decimal is carried out to two(+) places?
And if you hold a thermometer vertically above your head at arms length it reads colder and if you hold it vertically below your head at arms length it reads hotter. Tilting it backwards and forwards has the same effect.