Any AGW signal in UK temperature data ? – Nope !

The Central England Temperature data is the longest continuous instrument measurements in the world from 1650 – 2012 [1].  Do they show evidence of Anthropogenic Global Warming (AGW)? Likewise detailed UK station temperature measurements since 1940 are available through  Hadcrut4 dataset[2]. Do these show recent enhanced temperature rises due to ever increasing CO2 levels?  The answer to both questions is a definitive nope!  There is no AGW signal present in either  dataset  – see figure 1.

Fig 1:  Above - Annual average temperatures from 1650-2012. Red line is a linear fit, blue line is a Fourier low pass filter. Overlaid in purple is Hadcrut4 for UK stations.Below: Monthly average temperature anomalies for all Hadcrut4 UK/Ireland stations. In blue is a Fourier low pass filter. Red is a linear fit showing zero trend.

Fig 1: Above – Annual average temperatures from 1650-2012. Red line is a linear fit, blue line is a Fourier low pass filter. Overlaid in purple is Hadcrut4 for UK stations. Below – Monthly average temperature anomalies for all Hadcrut4 UK/Ireland stations. In blue is a Fourier low pass filter. Red is a linear fit showing zero trend.

The only significant continuous trend is an apparent  0.026C/decade recovery from the little Ice Age over the last 360 years. This has not changed or accelerated. There is no hockey stick!  In fact there has been no change whatsoever in UK average temperatures since 1940 !


Climate Extremes

The other scare story that we often hear is that the weather is getting more extreme due to AGW. Ever since I was a child there has  been a common misperception that for one reason or another the weather is always getting worse. Is that  not simply because UK weather often seems to let us down for holiday breaks ?  Is there any truth at all in the AGW claim  that meteorological records are being broken almost every day ?  Figure 2 shows the UK Met office records for extremes in temperature, rainfall and storms (wind). This collage is taken from their web-site at http://www.metoffice.gov.uk/climate/uk/extremes/.  As you can see most of  the climate records have been set in previous centuries! So no real worries there either.

Figure 2:  Official UK weather extreme records from the Met Office.

Figure 2: Official UK weather extreme records from the Met Office.

Given that there has been no climate change in the UK since 1940, Is it not perhaps time for a policy  rethink ?

References

[1] MONTHLY MEAN CENTRAL ENGLAND TEMPERATURE (DEGREES C) 1659-1973 MANLEY (Q.J.R.METEOROL.SOC., 1974) , 1974ON PARKER ET AL. (INT.J.CLIM., 1992), PARKER AND HORTON (INT.J.CLIM., 2005)

[2] Jones, P. D., D. H. Lister, T. J. Osborn, C. Harpham, M. Salmon, and C. P. Morice (2012), Hemispheric and large-scale land surface air temperature variations: An extensive revision and an update to 2010, J. Geophys. Res., 117, D05127, doi:10.1029/2011JD017139

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11 Responses to Any AGW signal in UK temperature data ? – Nope !

  1. Ed says:

    Very interesting indeed. Thanks.

  2. If AGW research was based on one set of readings from one location then I would have serious doubts about the quality of the research. The UK may end up being a country with a decreasing annual temperature in a warmer world, and as for extremes the farmers local to me are very aware of recent changes. Anecdotal I know, but records [both 100 year and since records began] have been broken almost monthly. The hottest years were however in the 00s and climate is not just heat- the Midlands suffered a long term drought up to last April [the wettest on record]. as a physicist I would have thought you would be very cautious about extrapolating conclusions from such a small data set.

    • clivebest says:

      AGW research is 90% based on climate modelling. If the experimental data do not support them then they should be either rejected or else modified to better agree with the data. Much emphasis is put on the fact that CO2 is a well mixed gas and its concentration remained fairly constant until man increased it by 30%. This is a global concentration figure not just in Hawaii or the Arctic but also in the UK. Water vapour on the other hand changes on a daily basis and can negate climate model predictions. To prove AGW, the theory must make precise predictions such as :

      1.Average temperatures globally will be 1 degree higher by 2050.
      2.Hurricanes will expend 30% more energy in 2050 compared to 2000.
      3.UK rainfall will be 30% less in 2050 than in 2000.

      The fact that they refuse to make such clear scientifically verifiable predictions, kind of relegates then to Voodoo science. It is obvious that the IPCC is running scared if you read the draft AR5 report, because there has been no global warming in nearly 20 years despite increasing CO2 levels.

      The (CO2) greenhouse effect is a scientific fact. The associated hype however isn’t.

    • sunsettommy says:

      Actually the UK is a special region because of the wide open expose of several different climate zones.

      The Cold North Sea,
      The polar based Icelandic flow,
      The moderating Contential flow,
      The arriving warm flow from the Gulf of Mexico.

      Just before the LIA came along there was a distinct increase in wet cold summers and the decline in the moderating flow from the Gulf of Mexico.The very thing that is happening now but will it last or fall back to the previous decades?

      The UK was completely under the ice in the previous Climate Winter because the two moderating forces were pushed to the south allowing the first two climatic patterns to dominate.

      Thus a long term cooling in the UK will mean a long term cooling for the northern hemisphere as well since they go hand in hand.

      The UK is a canary in the mine region.

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  5. Derek Tipp says:

    Hello Clive and thanks for the interesting post. I am currently in communication with someone from the Local Government Association who has replied to my request for scientific evidence to show that there has been significant climate change in the south of England in the past 60 years. Here is her reply:-

    “A summary of some key observed trends for the UK is as follows:

    Central England Temperature has risen by about a degree Celsius since the 1970s, with 2006 being the warmest on record.
    All regions of the UK have experienced an increase in average temperatures between 1961 and 2006 annually, and for all seasons. Increases in annual average temperature are typically between 1.0 and 1.7 °C, tending to be largest in the south and east of England and smallest in Scotland.
    All regions of the UK have experienced an increase over the past 45 years in the contribution to winter rainfall from heavy precipitation events; in summer all regions except north east England and north Scotland show decreases.
    Severe windstorms around the UK have become more frequent in the past few decades, though not above that seen in the 1920s.
    Sea-surface temperatures around the UK coast have risen over the past three decades by about 0.7 ºC”

    As she represents a serious organisation I assume she has obtained this information from somewhere like the Met Office. Can you give me some links to data which will give the true position on the above points. Can you see any way in which she could interpret the data to validate the reply she has given?

    • Clive Best says:

      Derek,

      Yes I suspect the statement was prepared by the MET Office. It contains some quantitative statements and some subjective statements such as “Severe windstorms around the UK have become more frequent in the past few decades, though not above that seen in the 1920s.”.

      I am using exactly the same data namely Central England Temperatures HADCet and HadCrut4 stations within the UK. If we look just at the last 60 years we get the following 2 figures. First HadCET

      and for the UK temperature monthly anomalies we get

      It is true that annual temperatures have been above long term averages from about 1990 to 2008, but since then they seem to have trended down. It is not really true that all seasons have warmed – for example November 2010 was the coldest November for the last 100 years.

      Furthermore if you look at the long term trends in the post you see a warm period around 1730. For HADCET temperature data there is a definite long term slow warming trend since 1650 which seems to be a recovery from the little Ice Age. So the last 20 years or so have been slightly warmer but it is not clear this does not include natural variation. I would say the case that this is due just to AGW is not overwhelming.

  6. derek tipp says:

    Thanks for replying. Is there any way the claims about winds and rain intensity can be verified by past records that you know of. Looking at the graphs, am I right to say that it is not statistically correct to claim that temperatures have risen by1.7C since 1970 as much of the recent rise has been wiped out by the recent downturn?

  7. Clive Best says:

    I would support a statement which said temperatures have risen by 0.5+- 0.5 degrees from 1970 to 2012.

    The records for temperatures can be found here

    Novemeber 2010 was the coldest on record .

    For rainfall the records are available here

    and very rainy days here

    Record wind gusts can be seen at the bottom of this table

    For me there is no convincing statistical evidence that rainfall or wind speed has really changed.

  8. Derek Tipp says:

    Hi Clive. Thanks for the links. I have been on the Met Office site myself and I think I have found the graph which they may have used: http://www.metoffice.gov.uk/climate/uk/actualmonthly/

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