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Climate Hustle

1934 is the hottest year on record

What the science says...

Select a level... Basic Intermediate

Globally the year 1934 was cooler than the 20th century average.

Climate Myth...

1934 - hottest year on record
Steve McIntyre noticed a strange discontinuity in US temperature data, occurring around January 2000. McIntyre notified NASA which acknowledged the problem as an 'oversight' that would be fixed in the next data refresh.  As a result, "The warmest year on US record is now 1934. 1998 (long trumpeted by the media as record-breaking) moves to second place." (Daily Tech).


The year 1934 was a very hot year in the United States, ranking sixth behind 2012, 2016, 2015, 2006, and 1998. However, global warming takes into account temperatures over the entire planet, including the oceans. The land area of the U.S. accounts for only 2% of Earth's total surface area. Despite the U.S. sweltering in 1934, that year was not especially hot over the rest of the planet, as you can see on the 1934 map below. Globally, 1934 temperatures were actually cooler than average for the 20th century.

1934Global T map 1934

2016global T map 2016

Figure 1. Global temperature maps for 1934  (top) and 2016 (bottom). Source NASA.

Climate change skeptics have pointed to 1934 in the U.S. as proof that recent hot years are not unusual. Choosing the year 1934 is an obvious example of "cherry-picking" a single fact that supports a claim, while ignoring the rest of the data. In fact they have to cherry pick both a location (the U.S.) and a year (1934) to find data that is far from the global trend. Globally, the years 2014, 2015 and 2016 are the hottest on record, so far.

Global T anomalies


Figure 2. Global land and ocean temperatures from 1880 to 2015. Source: National Climate Data Center


The fact that there were hot years in some parts of the world in the past is not an argument against global climate change. Regional and year-to-year temperature variations will always occur. The reason we are worried about climate change is that on average, over the entire world, the long term trend shows an undeniable increase in global surface temperatures and global ocean temperatures. This rapid global heating is dramatically altering the planet we live on.



Last updated on 7 August 2017 by Sarah. View Archives

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Comments 101 to 108 out of 108:

  1. LTO - If you are so concerned regarding the infill for certain regions in 1934 (an argument I find quite thin; the correlation strengths for those infills are well tested and established), then by all means simply compare the sampled areas in 1934 directly with the identical areas in 2016 - ignore the regions of increased coverage. And you will find, as per the OP, that 1934 was warm in a few regions such as the US, but overall the globe wasn't particularly warm (perhaps 0.1C below the 20th century average), and that the last few years are running perhaps 1C above the 20th century average, both in the subset well sampled in 1934 and in the world as a whole.

    In short, the climate myth claiming that 1934 was a hot year, and thus attempting to refute general temperature assessments, is both wrong and a bad idea, scientifically speaking.

    Given that, just what is your complaint about the OP?

  2. LTO - I looked back through your previous comments in your thread, and found your posting of a thesis by a John McLean, which somehow argues that HadCRUT is wholly unreliable. Is this the same John McLean who in 2011 stated (oh, so incorrectly) that temps were about to return to 1956 levels?

    If so, I would humbly point out that he's not a good reference due to past demonstrated errors. His temperature predictions are among the worst I'm aware of.

  3. And here's a discussion of that thesis at 'And Then There's Physics', which points out that the thesis was completed under the direction of two well known climate deniers.

    The science in that thesis is lousy, and it's not. a. good. source.

  4. LTO - I agree it would be better if we had side-by-side chart of error-bars, but again, the chart is valid for the purpose. Even with double the estimated error, the essential picture of differences between 1934 and now is unchanged - it is fit for purpose.

    As it is, as far as aware from the papers, a "map" of error estimates does not exist. The validation and error estimation methods instead work by latitude-range and sometimes ocean (eg the error bars for north atlantic are less than for north pacific).

  5. KR @102 and @103 ,

    you may not have considered the matter: but this thread contains a modicum of internal evidence that Dr McLean and poster LTO have a possible coincidence of identities.   Not conclusive of course, for the patterns of thinking are hardly rare in the deniosphere.


    [PS] No cyber-stalking. Speculations like this are extremely unhelpful and very unlikely.

  6. I will note that the Cowtan and Way temperature series includes gridded uncertainty measures, for measurements, coverage, etc. 

    Site here

  7. Moderator @105 , my apologies for speculating on the coincidences.

    KR @106 , thank you very much for that Cowtan & Way link.   I have usually regarded the so-called "tropospheric" UAH/RSS satellite data as having minimal usefulness in regard to planetary surface temperatures ~ but Cowtan & Way point out that the loose correlation of satellite & surface, can be quite helpful when infilling by kriging or other interpolation methods.   Presumably the modern infilling would provide some indirect support for the infilling of the circa 1934 records.

  8. Eclectic - I think Hansen and Lebedeff 1987 really answered the basic infill question, testing temperature correlations and showing that they hold to over 1200km.  The gridding in HadCRUT is rather crude, and C&W style kriging is far more accurate, but even the earliest HadCRUT data presents global data worth looking at. 

    LTO - If you have anything more solid than repeatedly disproven denier articles, or rather paranoid papers that claim any interesting work (ie, anything that hasn't been done to death before) is likely falsified (note: I'm referring to text since deleted by moderators from your post here), which indicates actual problems with infilling using temperature anomaly correlations, by all means point it out. 

    Barring that, your objections seem IMO to be an Argument from Incredulity

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