Convergence in Temperature Time Series

Climate science investigators Cowtan and Way [1] updated the HADCRUT4 global temperature time series to properly account for areas that had little representation, incorporating regions such as Africa and the Arctic using geospatial kriging techniques . The Arctic in particular has shown considerable anomalous warming that hadn’t been captured in that time series.  They have a methods page that contains details here.

This impacts the CSALT model by adjusting the temperatures upward in the last few years to better match the movement out of the “pause” regime that the fluctuation components plus relentless CO2 forcing have been predicting would occur. See Figure 1.

Fig 1 : Comparison of the Cowtan and Way update with the GISS global time series and CSALT model

The last year or two is still lagging in intensity but the trend is recently upward.

Fig 2 : Adjustments to HADCRUT4, notice the last few years shows a larger warming trend and the removal of the “pause”.

Incidentally, I believe that Kevin Cowtan is the Kevin C who contributed the SkS trend calculator linked in the sidebar.  An online commenter complained that Cowtan was a chemist specializing in X-ray crystallography, as if that was a bad thing. I did diffraction modeling for my PhD and I can tell you that this is puzzle solving at its finest;  trying to piece together our understanding of reality using limited data — by inverting wave interference diffraction patterns — prepares one for just about any challenge.

Fine work along with a companion piece here [2].

 Related posts

  1. Detailed Analysis of CSALT Model
  2. CSALT model
  3. Climate Variability and Inferring Global Warming   


[1] K. Cowtan and R. G. Way, “Coverage bias in the HadCRUT4 temperature series and its impact on recent temperature trends,” Q.J.R. Meteorol. Soc., p. n/a–n/a, Nov. 2013.
[2] T. Sloan and A. W. Wolfendale, “Cosmic rays, solar activity and the climate,” Environmental Research Letters, vol. 8, no. 4, p. 045022, Dec. 2013.

2 thoughts on “Convergence in Temperature Time Series

  1. The pieces of missing data are further described at href=”″>SkS and see the figure.

    The C&W hybrid update is available on KC’s trend calculator


  2. The UAH data is used to do the infilling of data points.

    As an SkS commenter said, “The fact that they used UAH satellite data to ‘bridge the gap’… that ‘popping’ sound you hear is Roy Spencer’s head exploding.”

    A recent Spencer post is incredibly deceiving in claiming an ECS of 1.3C: CSALT says the TCR of SST is 1.55C but Spencer says the GLOBAL average is 1.3C. Three misdirections in my opinion by Spencer
    1. He did TCR only but called it ECS.
    2. He didn’t include Land temperatures in the average.
    3. Using the subsurface layers confuses everyone.

    The first two are obvious blunders but the last one is puzzling. What temperature anomaly is Spencer trying to isolate? An average temperature down to 700 meters? That would certainly suppress an overall increase in comparison to using the top 50 meters and even more so the SST.


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