Claim: Human influence on climate dates back to 1930s

From the AMERICAN GEOPHYSICAL UNION and the Australian “ARC Centre of Excellence for Climate System Science” (you know, that outfit that gave “Ship of Fools” Chris Turney an award) comes this exercise in climate modeling numerology. From the introduction in the paper:

In this study we use the well-established Fractional Attributable Risk (Allen, 2003; FAR) framework to investigate the changing influence of anthropogenic forcings on record-breaking hot seasons and years for different regions around the world. The probability of record hot events is compared between climate model simulations with both natural and anthropogenic forcings and simulations forced by natural climate influences only.

They also go on to say they have detected emergence of AGW driven heat waves in the Central USA in recent years. From Figure 3. “FAR timeseries of record-breaking hot summers for the globe and five regions” here is the panel for the Central US:

central-us-modeled-heatwaves

They suggest that from 2000 onward, heat waves should be anywhere from 2 to 10 times more common. By that reasoning, this graph of record high temperature should also be increasing during that period, but it isn’t:

STATE_RECORDS[1]

As should this one:

high-temperature-trend

 

Note the dust bowl period in the 1930’s mainly affected the Central US.

In short, the entire study is an attempt to pull a desired result out of a set of data. Reading the paper, it seems clear to me that the conclusion existed before the paper was written.  Here is the press release for what it’s worth.


 

WASHINGTON, DC — Humans have triggered the last 16 record-breaking hot years experienced on Earth (up to 2014), with our impact on the global climate going as far back as 1937, a new study finds.

The study suggests that without human-induced climate change, recent hot summers and years would not have occurred. The researchers also found that this effect has been masked until recently in many areas of the world by the wide use of industrial aerosols, which have a cooling effect on temperatures.

“Everywhere we look, the climate change signal for extreme heat events is becoming stronger,” said Andrew King, a climate extremes research fellow at the University of Melbourne, Australia and lead author of the study. “Recent record-breaking hot years globally were so much outside natural variability that they were almost impossible without global warming.”

The researchers examined weather events that exceeded the range of natural variability and used climate modelling to compare those events to a world without human-induced greenhouse gases. The study was accepted for publication yesterday in Geophysical Research Letters, a journal of the American Geophysical Union.

According to the new study, record-breaking hot years attributable to climate change globally are 1937, 1940, 1941, 1943-44, 1980-1981, 1987-1988, 1990, 1995, 1997-98, 2010 and 2014.

“In Australia, our research shows the last six record-breaking hot years and last three record-breaking hot summers were made more likely by the human influence on the climate,” King said. “We were able to see climate change even more clearly in Australia because of its position in the Southern Hemisphere in the middle of the ocean, far away from the cooling influence of high concentrations of industrial aerosols.”

Aerosols in high concentrations reflect more heat into space, thereby cooling temperatures. However, when those aerosols are removed from the atmosphere, warming returns rapidly. The researchers observed this impact when they looked at five different regions: Central England, Central Europe, the central United States, East Asia and Australia.

There were cooling periods, likely caused by aerosols, in Central England, the central United States, Central Europe and East Asia during the 1970s before accelerated warming returned, and aerosol concentrations also delayed the emergence of a clear human-caused climate change signal in all regions studied except Australia, according to the study.

“In regards to a human-induced climate change signal, Australia was the canary in the coal mine for the rest of the world,” King said.

###

The paper: http://onlinelibrary.wiley.com/doi/10.1002/2015GL067448/abstract

Emergence of heat extremes attributable to anthropogenic influences
Authors
Andrew D. King, Mitchell T. Black, Seung-Ki Min, Erich M. Fischer, Daniel M. Mitchell, Luke J. Harrington, Sarah E. Perkins-Kirkpatrick

Accepted manuscript online: 7 March 2016

Abstract
Climate scientists have demonstrated that a substantial fraction of the probability of numerous recent extreme events may be attributed to human-induced climate change. However, it is likely that for temperature extremes occurring over previous decades a fraction of their probability was attributable to anthropogenic influences. We identify the first record-breaking warm summers and years for which a discernible contribution can be attributed to human influence. We find a significant human contribution to the probability of record-breaking global temperature events as early as the 1930s. Since then, all the last 16 record-breaking hot years globally had an anthropogenic contribution to their probability of occurrence. Aerosol-induced cooling delays the timing of a significant human contribution to record-breaking events in some regions. Without human-induced climate change recent hot summers and years would be very unlikely to have occurred.

73 thoughts on “Claim: Human influence on climate dates back to 1930s

    • Mycroft
      Do note the comment above: –
      ” (T)he conclusion existed before the paper was written.”

      Precision in a few words!

      Auto

      • They should have called it
        Fractional
        Attributable
        Risk of
        Storm and
        Temperature
        Related
        Extremely
        Temperamental
        Climate
        Hallucinations

        F A R S T R E T C H

    • They truly believe they are saving humanity from itself. Since most of them are far left cretins, they naturally use Alinsky’s framework as the means to attain their goals, subjugation of the human race to an elitist ruling class (them).

      • I always remember the words of one young communist I debated years ago. He declared that this time communism will work, because this time, they were going to be the ones in charge.

  1. Are they using raw or corrected records from the 1930’s? As various reports of what the raw records were from the 1930’s, at least in the US, it was warmer then than in the 2000’s.

  2. We tortured the data until it confessed!
    But of course they got their main aim – unquestioned parroting of their press release in the Fairfax papers across Australia and no doubt similar newspapers across the world.

  3. actually this “can be true”

    however then we come to the most underestimated factor ever: I’m somehow convinced that surface temperature is WAYS more sensitive to land use changes then to greenhouse gasses. the 30’s saw a very badly managed land use on a large schale in a large region.

    I suspect this added. However it’s not the full tale of the story: most is natural cause. but bad land management (land use) did add to the severity of it.

    so it has an anthropogenic factor in it, but then in a very different way.

    • It may be possible that land use was a contributor to “actual” land temperature records but cultivated land is cultivated land when it’s under the sun. I would suspect that any effect would more likely be from lower humidity due to moisture loss from extensive tilling practices. Also, don’t forget that UHI effects were much less in the 30’s. Also, I believe the records show that those drought years experienced reduced snow levels in winter as well- in spite of some of the record winter low temperatures which occurred at that time. The reality is that it was hot and dry in the 30’s during summer and cold and dry in the winters. I live in Saskatchewan in Western Canada and the all time record high was 47C in 1937. Non urban and damned hot. If AGW goes back to 1937 then it looks to me like we have a pause of 78+ years. The chart of record highs in the above article bear this out, as records should become less frequent as time goes on if there is no underlying trend. I’m not a statistician ( but I play one on TV)- there must be a precise formula by which new records accrue in a data stream with no trend. The highs should show this for any point on earth that has reliable data. If only NOAA and others knew what reliable looks like!

    • There is another very good counter to this theory and its very simple. The thirties was the era of the great depression when industrial activity and fossil fuel use dropped markedly. So we would in fact expect a reduction in global temperature rise.

  4. used climate modelling to compare those events to a world without human-induced greenhouse gases

    Great. Use a model that can’t even predict what actually happened to project back into a hypothetical past.

    A classic case of “garbage in, garbage out”

  5. Conveniently, the data set reaches ALLLL the way back to 1895 and the 2000’s is just plain unusual.

    I hardly think this pseudo science ought to be published here and could lead to the discredit of WUWT if the likes of Michael Mann choose to use it as evidence of Watt’s scientific acumen. /sarc

  6. Hmmm, yes – those aerosols. I’m reminded of the Swedish shopkeeper sketch – asked for deodorant he asked “ball or aerosol?” “Neither – I want it for my armpits.”

    Has anyone asked the aerosols whether they also work at 33,000 ft? I’ve seen dark smoke hang over cities – I’ve never seen it at cruising altitude. Can’t see how it would affect the satellite readings.

    • Actually it was the Swedish Chemists sketch from “Not the Nine O’clock News”! Still, an hilarious sketch!

  7. They don’t have a clue about “natural” climate drivers, but claim to have considered them all? When did I miss the trove of papers describing the climate drivers that created the Minoan Warm Period and the subsequent cold period, the Roman Warm Period and the Dark Ages Cold Period, the Medieval Warm Period and the Little Ice Age? I think any paper claiming to have “…examined weather events that exceeded the range of natural variability…” needs to first be able to fully explain the previous natural variability.

    • Bruce,
      Do note the comment above: –
      ” (T)he conclusion existed before the paper was written.”

      Precision in a few words!

      Auto

  8. Another whack-a-mole paper. In this one Aussies compare models that do not properly hindcast and do not regionally downscale to find significant heat wave episodes that unfortunately do not appear in pristine temperature records, and which got disappeared in ‘adjusted’ records for regions like the US or the wine country of New South Wales (Rutherglen Ag Research station). Whack!

  9. Anthony writes: “In short, the entire study is an attempt to pull a desired result out of a set of data. Reading the paper, it seems clear to me that the conclusion existed before the paper was written.”

    These are the fundamental problems with the hypothesis of human-induced global warming. As a result, the climate science community still can’t realistically differentiate between natural and manmade global warming.

  10. Wouldn’t it be more PC to merge feminist postcolonial science studies and feminist political ecology, the feminist climatista framework generates robust analysis of gender, power, and epistemologies in dynamic social-ecological systems, thereby leading to more just and equitable science and human-climate interactions.

  11. ” far away from the cooling influence of high concentrations of industrial aerosols.”

    Apparently there is no wind in Australia to mix aerosols in the atmosphere but they are still building windfarms. Cuckoo Cuckoo. Where do they think the monsoons come from? How do El Ninos and La Ninas form and move without changes in pressure.
    These people are grasping at ice cubes in summer.
    As a matter of interest, our Prime Minister who is a very firm believer in catastrophic warming held a meeting with his State party last night. He was heckled for his warming beliefs and his announced position of refusing to listen to sceptics. The vote was, for 70%, 30% against/unknown to have debates between IPCC post modern science and the NIPCC group.

  12. You mean humans had an impact on the climate back in the 1930? Phew! I thought it was all my fault.

  13. So let me get this right.
    They are claiming that we would have had a lot more man made warming, have it not been for the man made cooling. Had they just come back from the bar when they wrote this.?

    • “Had they just come back from the bar when they wrote this.?”

      More like they are participated in experiments for Timothy Leary.

      • I think it’s safe to say the Timothy Leary “experiments” never ended for the AGW crowd.

  14. If they just “unadjusted” the past temps then the 30’s could be hot again. They might lose a few of the recent “hottest ever” records but, since they’re blaming Man from the 30’s on, it’d be a win-win.
    They can be honest about the past while still being dishonest about the cause.
    (Of course, support for Hansen’s stuff will need to go the way of The Hockey Stick but that’s a small loss as long as support for the need to control cause remains.)

  15. Andrew King went on to describe the database program his team created for this project. He said, “The Meteorological Yearly Assessment of Surface Stations database is quite a novel and highly useful tool we developed for the exploration of surface station temperature records. With this tool, we looked into the past for signals related to human attribution of global warming and heat waves.” Dr. King further added, “Now when we need to explore these difficult questions on Anthropogenic Global Warming, we can now probe MYASS to extract the answers.”

    (note: a parody with some element of truth)

  16. Population of the world in 1930 = 2Billion (US 123Million). Population in 2014 =7.1Billion. (US 317Million). Global CO2 1600 to 1900 ~ 275ppm in 1930 ~ 285ppm, in 2015 ~400ppm.

    I’m sure they must have provided this data and explained why, with 1/3 the population, and 285ppm CO2, merely 10ppm above the pre-industrial revolution we would have record heat in 1930s. This was the first manipulations of GISS. Frustrated by all the records of heat waves and temperatures having occurred in the 1930s, they pushed that part of the curve down, although as late as 2007, the agreed that the record in the US was still the 1930s. Now, of course, they have deep sixed the 30s and 40s before all was lost. The Ship is gone but the Fools still abound.

    • Just the beginning- a lot of records go back to the 1890’s. They’ve just created a pause from the 1930’s to the present. Next they will be saying we started this in 1890. Your commentary on 1930 CO2 levels can be recycled back another 40 years. Their models are going to have to start looking like an explosion in a number factory.

  17. Data torture is not a monopoly assigned to the extremist.
    Here is raw data from my Australian home town, also the home town of many of the Australian ARC brigade, presented in a way that minimises UHI, screen relocations and the rest.
    From the site that BOM long held dearest and best.
    Original data as issued by BOM shows the worst time for hot events each year in Melbourne was the 5 years just before 1900, then the mid-1960s. The 2000s to 2012 scarcely figure.

    Come on, you guys at the Centre of Excellence.
    How do you spin away the very clear implications of this very clear graph???
    Do you really need to ignore data before your chosen 1910 start date for ACORN-SAT?
    Geoff.

    • AS per my comment above, many record highs in North America were in the 1890’s. I guess it wasn’t ” global” warming- just the Northern and Southern Hemispheres!

  18. I would think that records set is more a function of station growth and dropout, plus station changes from one kind of sensor to another kind of sensor. It seems these researchers ran over this first encountered pathology without even saying, “pardon me but may I pass.”

  19. Such studies must first look in to the precipitation patterns — droughts and floods. Without such study, the results can be interpreted as preconcieved by the uthors. This is a bad research.

    Dr. S. Jeevananda Reddy

    • It’s no interpretation Dr. These results are absolutely pre-conceived. And yes, it is bad research.

  20. “The researchers examined weather events that exceeded the range of natural variability …”
    So how could they do that? Where is the ‘range’ of natural variability quantified?
    I suspect this is just a way to try and remove the valid sceptical objection to the claims that recent hot weather is outside norms by asking ‘what about the 30’s?’. By claiming them now as ‘man-made’ they try to remove a glaring objection to the alarmism.
    Just been reading ‘1984’, this is classic Big Brother rewriting history…

  21. The great heatwaves and droughts in the Dust Bowl were due to a combination of one or more multidecadal oscillations and the farming practices during and before the mid 1930s.

  22. Surely, this claim is at its root, circular.
    Surely they are now testing their assumptions using simulations – which are already simulations of what would happen if this set of assumptions are assumed to be true.
    We already know that models will show that anthropogenic greenhouse gases will cause most of the warming and that very little of the warming will have its origin in natural variability – because that’s the assumption upon which the models are based.
    The modellers effectively told the model to do this. Now the model is telling climate scientists that this is what the model does…
    Shouldn’t someone be predicting something and then testing something against reality?
    Have I missed something?

    • ..I have a model of my model that proves that my model is better than your model ! So there !

      • I’ll see your model and raise you 8 models. it’s risky I know, how can we lose? Hahaha

  23. I decided to let my Scientific American subscription expire many years ago when they declared that the last ice age ended because of agriculture.

  24. CO2 must have been the cause of early 20th century warming because the modelers cannot find another reason.
    Step forward the great Dana Nuccitelli at Sks on the settled science.

    While natural forcings can account for much of the early 20th Century warming, humans played a role as well. Additionally, the early century warming wasn’t as large or rapid as the late century warming, to which these natural factors did not contribute in any significant amount.

    We can all eagerly await Dana’s corrective Guardian article.

  25. If you want to look for human effects on the climate look at something other than CO2. From what I remember reading, the USDA went to great lengths to teach farmers dry land farming after the dustbowl. They publicized planting wind breaks of trees, putting trees around housing. Planting cover crops immediately after plowing. Using contour plowing to prevent excessive run off. Raising cattle instead of farming. Crop rotation, etc. It was pretty well accepted from the 50’s on that the dustbowl was primarily due to the wrong farming practices in the early part of the century. But it was a fairly localized problem and made worse by the recurring drought conditions that were known to happen fairly periodically.

    Now almost all farmers/ranchers in the area go to great lengths to preserve and improve the soil and use good practices.

    • The 1930’s dustbowl occured during a warm period in earths recent history, trying to cool the past again? Farmers back then didn’t know how to farm?

      Trying not to fucken swear so hard…

    • The 1930’s dustbowl occured during a warm period in earths recent history, trying to cool the past again? Farmers back then didn’t know how to farm?

  26. See, it all goes back to the discovery of fire. All those campfires added up. Who invented the match anyway?

  27. It’s all well and good that they don’t live in small cold countries, winters are just as cold as the state they vote to rule them.

  28. The researchers examined weather events that exceeded the range of natural variability and used climate modelling to compare those events to a world without human-induced greenhouse gases.

    I can’t see any basis for declaring that these events exceed natural variability or to assume that the comparison with a theoretical world is valid unless the models have been thoroughly validated. Which they haven’t, and to do so would take a hundred years or so.

  29. Notably, Mr.Gore invented:
    1. the use of Global Warming hysteria as a tool for getting elected and
    2. the use of Global Warming hysteria as a tool for getting rich by marketing fictitious carbon quotas.

    • You could shorten that to Al Gore is a tool. But then that would be an insult to tool makers who do real, useful, work.

  30. “The researchers also found that this effect has been masked until recently in many areas of the world by the wide use of industrial aerosols, which have a cooling effect on temperatures.”

    Sounds like, if we really try hard, we could induce a GGS (Goldilocks Global Stasis) … but I guess that would also rate as “still happening and even worse than we thought!”

  31. They should try that for the years 900-1000. I’m sure their models will find that the human-emitted carbon dioxide at that time has a much greater effect than previously thought. Success!

  32. The AGU played a role in this piece of horse pucky? How does the AGU retain it’s membership? I would be embarassed. to say that I was a member.

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