Berkeley Temperature record update2 the longer record

In my previous two posts on the Berkeley temperature record (here and here) there was discussion of time intervals and how they influenced perceptions of temperature change.

Berkley2-300x236The first graph here is what the Berkeley team released to the press. It covers the period 1800 to 2006.  The expanded Y- axis scale gives the impression of a significant recent rise in temperature.

If one looks, however, at a longer record the perception is different.  The second graph is the Central England Temperature record (CET), as far as I know, the longest  continuous instrumental record in existence. It covers the period 1659 to 2009.  Also plotted with the temperatures are carbon dioxide emissions (black line).


The impression from CET is that the temperature has risen steadily and modestly as the planet warmed up from the so-called Little Ice Age which reached its coldest around 1607.  We see within this record shorter intervals of more rapid warming and cooling.  We also see that the rapid rise of carbon dioxide emissions has had no apparent effect.

More discussion and more long temperature records from Europe can be found in this post:

A short anthology of changing climate

And for some additional perspective, the graph below, based on proxy data, shows the relative temperature for the past 10,000 years.


See also:

A Perspective on Climate Change a tutorial



  1. Jon, In glacial timeframes CO2 does indeed lag temperature (T), but on historical timeframes it definitly does not. This is because the global warming in glacial timeframes was not initiated by anthropogenic CO2. During interglacials CO2 was a feedback. The forcing was usually orbital variations (although there are others). When the forcing was great enough CO2 was released (as well as CH4) from many sources, the largest being the oceans. This story of conflating forcings and feedbacks is one of the commonist ways for denialists to confuse the nonscientist. The story of anthropogenic climate change is a story of forcings and feedbacks. We humans, for the first time in the history depicted on your charts, have become a climate forcing. You say that “when one looks at a longer record the perception is different”. It’s not just that the perception is different Jon, it’s that the realities are different. The forcings and the feedbacks are different.

    Please notice on your last chart that the fastest rise in T was ~300 years and was a little more than half a degree C. The most recent period has shown a 60% greater rise in half the time (.8 degrees since 1850).

    Jon, I’m a little mystified by your continuing insistence that the charts are somehow designed to appear (in your words) “scarier” than they are in reality. The charts are simply a method of displaying relationships. The only thing scary is a person who doesn’t look at the scale. Look at your second chart and tell me the y-axis scale for the CO2 line. Oops, there isn’t one. Now, although still not “scary”, it certainly begs the question as to what the author’s intention was. Of the three charts shown only one is inaccurate, and it’s not the one you pointed out.

    Lastly, please note the trend line in green. Then do a regression analysis to determine a trend line for the period from the dashed black line to the present. Now that’s an increase. John

    1. I agree that one of the great controversies is the still little-understood relationships between forcings and feedbacks. I maintain that the hypothetical forcing of human carbon dioxide emissions are insignificant compared to other cycles or forcings. I have often asked of commenters to provide some physical evidence that human carbon dioxide emissions have a significant effect on global temperature. So far, none have provided that evidence.
      As to the carbon dioxide Y-scale, look on the right side of the chart.

  2. Jon, Just to be clear, I should not have said there was NO y-axis for the CO2 emissions. It’s that the use of Gigatons relative to the nominal PPM is, at the very least, questionable. JP

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