Saturday, 31 January 2015

Temperature Pauses and Climate Science

Anthony Cox

In 2011 Rahmstorf and Foster [F&R] supposedly proved temperature was really rising despite the pause because AGW warming was still occurring.

F&R claimed to have isolated the AGW warming signal by removing the temperature impact of exogenous factors such as volcanoes, ENSO and the sun. But they made a number of mistakes.

One of those mistakes is they include the temperature trend in the multivariate regression; they say this:
Using multiple regression to estimate the warming rate together with the impact of exogenous factors, we are able to improve the estimated warming rates, and adjust the temperature time series for variability factors.”

But trend is NOT an independent variable, it is dependent on exogenous factors so the issue is should the trend have been included in the multivariate regression analysis? The short answer is no because the trend itself is contributing to the finding of the trend; in effect F&R are using the GISS temperature to prove the GISS temperature. That is statistical chicanery.

Now we have another attempt by the AGW factory to prove the temperature pause isn’t happening and in fact the IPCC model predictions are consistent with the observations. This time the paper is by Marotzke and Forster. [M&R]

M&R look at 2 trend periods: 15 year, which coincidentally is the period officially recognised by the AGW factory as being the length of a temperature pause which is climatically significant [see page 24 here], and 62 years, which coincidentally is about the length of a full Pacific Decadal Oscillation [PDO] cycle made up of clumps of El Nino and La Nina events.

Like F&R,  M&R also isolate exogenous radiative forcing but also claim to quantify internal factors like feedback and ocean uptake of heat. On this basis they conclude:
The differences between simulated and observed trends are dominated by random internal variability over the shorter timescale and by variations in the radiative forcings used to drive models over the longer timescale. For either trend length, spread in simulated climate feedback leaves no traceable imprint on GMST trends or, consequently, on the difference between simulations and observations.
This is an astounding claim. M&R, again like F&R, have used a multiple regression approach but unlike F&R who just treat temperature as an independent variable, M&R treat a dependent variable, feedbacks, as both a dependent variable and an independent variable as internal variability.

Feedbacks are climate responses to exogenous forcings. But as Spencer and Braswell show the distinction between feedbacks and forcings is artificial and unreal with such prominent climate factors as clouds capable of being both. It is therefore no wonder M&R find no traceable imprint on GMST trends by feedback only internal variability in the short term or 15 years, and radiative forcing in the long term, 62 years, because feedbacks are both examples of internal variability and forcing.

F&R used GISS temperature to prove GISS temperature; M&R have used feedbacks to prove no feedbacks.

There are other issues with the paper, like with F&R. M&R say they base their multiple regression approach on the Earth’s surface energy balance. That balance entirely proves a real temperature pause not a faux pause masking the inexorable upward trend of AGW temperature. The reason is readily apparent in the observations which show both no heat going into the ocean and an increase in longwave radiation leaving the Earth since 1998, when the temperature pause began:

The temperature pause is real and the attempts by the AGW factory to disprove it are becoming ludicrous. Roy Spencer simply rebuts them with this graph:

All the statistical shenanigans by F&R and M&R can’t disprove that.


  1. After the end of the Little Ice Age (in the middle of 19th century, around 1850), global temperature started to rise, the main reason of this phenomenon being the decrease of the volcanic activities. But naval war interrupted a steady warming trend two times yet.

    World War I ended with a severe “bang” in the late 1918.

    There is nothing clearer than the beginning of a “big warming” that occurred concomitantly with the end of WWI, in November 1918.

    World War II (1939 – 1941): In the autumn of 1939, the naval warfare ended within four war months which reversed the two decade warming trend and determined the cooling phenomenon which started with three extreme war winters in Northern Europe and which lasted four decades, until 1980.

    What lead us to the 1980 moment and what happened after that is explained largely in the Booklet on Naval War changes Climate, that you can read on

    1. Hi Jean; TSI started increasing about 1850 and its increase correlates well with temperature increase over the same period; see Figure 1 here: See also David Stockwell's paper at Figures 4 -7:


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