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Global Temperature Updates – 2012

January 23, 2013

By Paul Homewood


While Obama is imploring us to stop the global warming that is bringing us “the devastating impact of raging fires, and crippling drought, and more powerful storms”, it would seem to be a good idea to see exactly what global temperatures have been doing in the last year.



December Updates

First, let’s look at the December numbers, as there have been some significant changes.


December 2012 0.10 0.21 0.27 0.44
Change from last month -0.09 -0.07 -0.25 -0.24
12 month running average 0.19 0.16 0.44 0.56
Average 2002-11 0.26 0.19 0.47 0.59

[Remember all four sets are based on different base periods, so the absolute numbers are not directly comparable]


Points to note:-

  • Although HADCRUT and GISS show larger drops than the satellites, UAH and RSS both showed falls earlier in Oct/Nov, that were not matched by the others.
  • All three sets share a remarkable degree of agreement, in that the current 12-month average is running just below the 10 year average.
  • This month’s temperatures are remarkably low by historic standards. For instance, in the last ten years, there have only been three months when the HADCRUT figure has been lower.
  • ENSO conditions have been neutral for the last three months, and the temperature drops in the last couple of months appear to reflect the ending of a short lived El Nino conditions over the summer. More detail here.
  • The retrospective changes made by GISS, see here, are included in the above analysis. They tend to affect comparisons prior to 1998, rather than with recent years.
  • Quick analysis of HADCRUT data shows a larger drop of 0.41C in Northern Hemisphere temperatures, though Southern Hemisphere is also down by 0.09C.








Annual Summary

 Before we look at temperatures, let’s just see what the ENSO index has done this year.


The monthly figures for 2012 are :-

Month MEI
Dec 2011/Jan 2012 -1.046
Jan/Feb -0.702
Feb/March -0.410
March/April +0.059
April/May +0.706
May/June +0.903
June/July +1.139
July/Aug +0.579
Aug/Sep +0.271
Sep/Oct +0.103
Oct/Nov +0.166
Nov/Dec +0.037

The average for the year is +0.15, so it would be reasonable to classify it, overall, as ENSO neutral. Probably the last time neutral conditions applied for a sustained period was between April 2001 and March 2002. The current running averages for all four sets are close to or below the average seen in 2002.

Understanding this background is important when reviewing temperatures during the year.


The following graphs compare the annual temperatures over the last 10 years. None of them show any evidence of an increasing trend.







Perhaps the President might care to tell us what global warming he is talking about!




Temperature datasets are available  below.





  1. Ray permalink
    January 23, 2013 4:58 pm

    I notice that you don’t mention NCDC/NOAA, the other non-satellite anomaly series. The changes in that series are in fact very similar to NASA/GISS and HadCRUT, i.e. December = 0.4075c, down 0.2558c (apparently the figures are accurate to 4 decimal places!).

    • January 23, 2013 5:00 pm

      My understanding is that NCDC are using the same GHCN data as GISS, except they do not adjust for UHI. Therefore I don’t think they can claim to be independent.

      • Ray permalink
        January 23, 2013 5:14 pm

        I didn’t know that, but after adjustment to 1961-90, the NCDC/NOAA December figure works out at 0.2695c, identical to HadCRUT4 to 3 decimals, compared with 0.330c for NASA/GISS, (based on annual figures).
        Maybe the NASA/GISS adjustment for UHI actually increases the anomaly!

      • January 23, 2013 5:26 pm

        That’s interesting. It suggests that the GISS figures themselves would have been close to NCDC before the famous “GISS adjustments” were made.

        Compared with the 1961-90 period, the adjustments seem to have added about 0.10C of warming to GISS.

  2. January 23, 2013 9:24 pm

    Reblogged this on Tallbloke's Talkshop and commented:
    Important new update on global temperature metrics from Paul Homewood.

  3. January 23, 2013 10:16 pm

    Excellent post Paul. Gratefully reblogged at the talkshop.

  4. January 24, 2013 9:11 pm

    How the hell do you measure hundreds of observations to a half a degree accuracy and arrive at a global temperature anomaly with several decimal points ?

    ‘Nuff said really.

  5. Andy DC permalink
    January 26, 2013 11:36 pm

    The lack of trend is putting me to sleep. Not exactly a hockey stick configuration.

  6. Ray permalink
    January 27, 2013 10:53 am

    Research by the University of Oslo seems to confirm that past predictions of warming have been exaggerated:

    “But the researchers were surprised when they entered temperatures and other data from the decade 2000-2010 into the model; climate sensitivity was greatly reduced to a “mere” 1.9°C.”

    This is no surprise to some of us!

  7. R James permalink
    June 20, 2013 11:08 am

    It’s interesting that the scientific method is to test an hypothesis against real data. If they don’t match, change the hypothesis. Both GISS and Hadcrut decided to try changing the data, but it wasn’t enough to change things.

    Now the scientists are trying to work out why real data doesn’t match the hypothesis. The answer is staring them in the face, and they can’t see it, or admit it – the hypothesis is wrong!!!

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