The Disconnect Between Theory and Reality- Part 2: Winters vs Summers


It was two years ago in 2013 that I last posted on the difference between climate scientists’ expectations and reality, so in this series of posts I bring these points up to date, and add a couple of related points.

What the climate scientists tell us:

Dr Karl Braganza in The Conversation on 14/06/2011 lists the “fingerprints” of climate change (my bold).

These fingerprints show the entire climate system has changed in ways that are consistent with increasing greenhouse gases and an enhanced greenhouse effect. They also show that recent, long term changes are inconsistent with a range of natural causes…..
…Patterns of temperature change that are uniquely associated with the enhanced greenhouse effect, and which have been observed in the real world include:
• greater warming in polar regions than tropical regions
• greater warming over the continents than the oceans
• greater warming of night time temperatures than daytime temperatures
greater warming in winter compared with summer
• a pattern of cooling in the high atmosphere (stratosphere) with simultaneous warming in the lower atmosphere (tropopause).

And later

Similarly, greater global warming at night and during winter is more typical of increased greenhouse gases, rather than an increase in solar radiation.

In this post I look at whether there is a pattern of greater warming in winter than summer.

This indicator appears to be FALSIFIED for both Northern and Southern Hemispheres:

Fig. 1:  Winter vs Summer, Northern Hemisphere (UAH)

summ win NH

Fig. 2:  Winter vs Summer, Southern Hemisphere (UAH)

summ win SH

And at the Poles:

Fig. 3: Winter vs Summer, Northern Polar region (UAH)

summ win NP

Summers warming faster than winters.  And in Antarctica:

Fig. 4: Winter vs Summer, Southern Polar region (UAH)

summ win SP

Winters (which are mostly night) are cooling much faster than summers.

In Australia overall however, winters are warming faster than summers.

Fig. 5: Winter vs Summer, Australia (UAH 1979-2015):

summ win Oz uah

And Acorn surface data since 1979:

Fig. 6: Winter vs Summer, Australia (Acorn 1979-2015):

summ win Oz acorn 7915

And since 1911:

Fig. 7: Winter vs Summer, Australia (Acorn 1911-2015):

summ win Oz acorn 19112015

However, the patterns are very different in different Australian regions.  North Australia has winters warming faster than summers:

Fig. 8: Winter vs Summer, Northern Australia (Acorn 1911-2015):

summ win Oz nth

While Southern Australia has exactly the reverse:

Fig. 9: Winter vs Summer, Southern Australia (Acorn 1911-2015):

summ win Oz sth

Let’s look at different parts of the South, first the South East:

Fig. 10: Winter vs Summer, South Eastern Australia (Acorn 1911-2015):

summ win Oz SE

And the South West:

Fig. 11: Winter vs Summer, South Western Australia (Acorn 1911-2015):

summ win Oz SW

This shows a particularly strong summer warming effect.

In the North, the pattern seems driven by greater summer rainfall and drier winters:

Fig. 12:  Summer and Winter rainfall anomalies, Northern Australia

summ win Oz rain Nth

There has been much less winter rain in the Southwest (in the Southeast, there has not been as much variation):

Fig. 13:  Summer and Winter rainfall anomalies, South Western Australia

summ win Oz rain SW

In both the North and Southwest, there are distinct changes in rainfall in the late 1960s or early 1970s:

Fig. 14:  Northern Summer rainfall changes

summ rain Nth

Note the long term slow decrease to 1973, the wet 1970s and dry 1980s, and all except 6 wetter than average seasons since 1991.

By contrast, the South Western rainy season shows a long term slow increase with great variability until the 1960s, with a sharp step down in 1969, and another in 2001, with less year to year variability.

Fig. 15:  South Western Winter rainfall changes

winter rain SW

This shows up in trend maps of summer and winter rainfall 1970-2014:

Fig. 16:  Trends in summer rainfall

summ rain 19702014

Fig. 17:  Trends in winter rainfall

winter rain 19702014

The effect of less winter rain on temperatures in the following summer in South Western Australia is clearly seen in this scatterplot:

Fig. 18:  Summer means and previous winter rain:

summ T vs win rain SW

While the IPCC and its acolytes in the Climate Council predict less rainfall for southeastern and southwestern Australia, this would not be difficult given the trend for southwestern Australia had been established for 20 years before the IPCC was even formed, and 45 years before AR5. Northern Australian rainfall is not mentioned.

Assessment of this evidence for the enhanced greenhouse effect: FAIL.  Tropospheric data show this to be falsified in both Hemispheres and both Poles.  Australia appears to go against this pattern, but drastic changes in rainfall patterns in the Northwest and Southwest appear to be involved in the difference between north and south.

Theory has been mugged by reality yet again.

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12 Responses to “The Disconnect Between Theory and Reality- Part 2: Winters vs Summers”

  1. reichforthesky Says:


    Which of the myriad of UAH data sets did you use to generate for Figure 1? Which months did you use for summer and winter?

    If I use UAH V6 beta 4, I get similar relationship as you do with summer trends being greater than the winter.

    see – .

    However if you use the latest beta 5 set of data you get exactly the opposite relationship with winter trends being greater than the summer trends!

    see – .

    By the way I used the average of Dec, Jan and Feb for my winter values and June, July August for my summer values.

    I haven’t yet done any more analysis yet, and I am not sure whether I should bother , but this shows you the increasing fraught use of the UAH data set.

    Every version brings a new trend to the table and you can now cherry pick which ever data set you require to try and prove any point. It really is a moveable feast.

  2. kenskingdom Says:

    I used Beta 4, and I’m glad I did. I hadn’t realised Beta 5 was released. Beta 5 gives ridiculous values, and I get the opposite to you- strongly negative for both. I suspect something is wrong with the dataset and will check again. Stay tuned. And yes, I do know about summer and winter months in the northern hemisphere.

  3. kenskingdom Says:

    Mike, I have double checked Beta 5 with my plots.

    NH- winter warming more than summer ((0.14 v 0.12)
    SH- summer warming faster.
    Arctic and Antarctic: ditto.
    Australia- winter warming much faster ( 3 times faster). This seems odd to me as well.

    Thanks for bringing this to my attention. I will check further with other trends.

  4. reichforthesky Says:

    Hi Ken,

    I just checked the RSS data for N.H. which is in line with the UAHv6 beta 4 data i.e. The RSS summer trend (0.176 C per decade) is greater than the winter trend (0.157 C per decade).

    However things are very differnet for the USA land based data from the NCDC site (see ) which gave the following chart – .

    The winter trend (0.88 C per decade) is double the summer trend (0.44 C per decade) from 1895 until the present. This is even more pronounced than the difference for Australia shown above for both UAH and Acorn..

    So in the end I think you will find that the answer you get is going to rely on the selection of a appropriate data set and an appropriate region.

    • kenskingdom Says:

      Agreed: globally (or for very large parts) gives better analysis, though regional differences are interesting and need further investigation as they can give insights into what happens more broadly. Which is what I do.

  5. MikeR Says:

    I have done it again with my name!

    Miker. The artist formerly known as reichforthe sky

  6. Neville Says:

    Ken I think your graph for south polar region is showing the wrong trend box numbers? Also the boxed trends in fig 7 seem to be wrong.
    But I think we can say that the global trend shows the opposite to the AGW theory, so another fail. Also isn’t the AGW theory supposed to show extra warming in the mid trop first and through enhancement to then impact the surface temps? But the 3 satellite data-sets and balloons are shown to be warming slower than the surface data- sets. Surely their cart before the horse shows another epic fail?
    Also the non UHIE US stations of Watts study shows about 50% less warming than the other contaminated surface data-sets. And if the US surface data is that hopeless then garrwwwd knows what the rest of the world surface data sets could be.
    But without that extra 50% warming from endless adjustments and UHIE the surface data would be similar to the satellite and balloon data-sets. All up the theory seems to have failed miserably.

  7. MikeR Says:


    Which version of UAH are you using for the south polar region?. You get a totally different set of trends and depending on whether you are using v5.6, v6 beta 1 , v6 beta 2, version 6 beta 3, version 6 beta4 or the latest, and possibly not so great ,v6 beta 5. The differences in trends between the 6 versions strongly depend on the region also.

    As a good engineering friend of mine said with a wry grin “The greatest thing about standards are that there are so many to choose from” . UAH satellite data illustrates this perfectly.

  8. MikeR Says:

    Hi Ken,

    Using the UAH V6 beta 5 for Australia we get the trend for winter being massively higher than for summer-

    see –

    I get exactly the same result as you for beta 4.

  9. MikeR Says:


    With regard to the balloon data. The Ratpac A data (850-300 mbar) from 1979-2015 shows a trend of 0.170 degree per decade.

    The trend data for GISS for the same period is 0.164 degrees per decade .
    The trend data for HadCrut for the same period is also 0.164 degrees per decade .
    The trend data for NOAA for the same period is 0.155 degrees per decade .

    The trend data for RSS satellite for the same period is 0.123 degrees per decade .
    The trend data for UAH v5.6 satellite for the same period is 0.142 degrees per decade .
    The trend data for UAH v6 beta 4 satellite for the same period is 0.114 degrees per decade .

    Neville, would you like to reconsider your reference to the balloon data?

    Just one other thing to note while I am here the UAH5.6 data shows the highest correlation with the RatPac A data (rsq=0.96) but the slope is only 84% . For the UAh v6 beta 4 the correlation drops significantly to 0.85 and the slope is 70% of the RatPac slope.

    It looks like v6 needs to be significantly reworked. Version 5.6 seems to be the best version of UAH in terms of correlation and it its trend is also the closest to the surface data.

    I am get tired of posting graphs but I can post the relevant graphs upon request.

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