Pesky German Scientists

German Physicists: Late 20th Century Warming “Nothing Unusual”

Posted by John Hinderaker in Climate

Powerline

As regular readers know, a battle over global warming hysteria is raging among scientists, and the alarmists are consistently getting the worst of it. German scientists Horst-Joachim Lüdecke, Alexander Hempelmann and Carl Otto Weiss have published two influential studies in the European Geophysical Union journal. The first, published in 2013, examined the past 250 years of climate history. The second, published earlier this year, extended the research through the past 2,500 years.

Their findings are consistent with the main currents of modern climate science (as opposed to climate politics):

The analysis of the past 2500 years involved data from tree rings, sediment cores, stalagmites, etc. A plot of the data yields a climate operating with cyclic behavior.

Compared to the maxima and minima of the past, the current minima and maxima show that there is nothing unusual happening today. The scientists say today’s temperature changes are within the normal range. The German authors write: “Especially the 20th century shows nothing out of the ordinary.”

For better or worse, these scientists argue that global cooling is likely during the next 60 years:

The German scientists write that one result of the well established cyclic behavior over the past 2500 years is that it is justified to assume that the De Vries / Suess solar cycle will continue in the future.
They write that this means that “global cooling is to be expected over the next 60 years (Figure 3)”.

As for the last 250 years, the German scientists examined the oldest continuous thermometer records, as well as ice cores and stalagmites. They found periodic (cyclic) changes only:

Lüdecke, Hempelmann and Weiss also examined the oldest existing thermometer datasets going back some 250 years taken at the locations of Kremsmünster, Vienna, Prague, Hohenpeißenberg, Munich and Paris. Their study also included ice cores and stalagmite datasets, which the scientists say “show exclusively periodic climate changes in fine detail. There is no trace of aperiodic effects, such as from the continuously rising CO2 concentration in the atmosphere (Figure 4).”

Figure 4: Central Europe temperature (black, smoothed, agrees with the Antarctic temperatures) and the sum of the 6 strongest cycles (red), as found with the cycle analysis of the black curve. The perfect agreement between red and black shows that non-cyclic impacts (such as the steadily increasing atmospheric CO2) play no role for the temperature. Only the cycles correctly reflect the measured temperatures.

There has, of course, been a slight warming since the end of the Little Ice Age (thankfully), although we are still living in an age of relatively low temperatures. Of this, the authors say:

The German trio of scientists says the 0.7°C of warming occurring since the late 19th century is the result of the increase in the De Vries / Suess solar cycle and that the well-known oceanic AMO/PDO oscillations can also be seen. “These two cycles practically determine by themselves the earth’s temperature.”
The scientists add that the “pause“ in global warming is caused by the AMO/PDO, which has been on the decline since 2000. The De Vries / Suess solar cycle allows a general cooling up to the year 2080 to be predicted and that the global temperature will reach a level last seen in 1870.

In a parting shot at the politically-motivated, unscientific alarmists, the three Germans point out that “50% of the temperature increase expected to happen by 2100 should have taken place by now – if such a CO2 warming were true. The scientists say that the way things stand now, if the CO2 effect were real, the future warming up to the year 2100 could be at most 0.7 °C.”

President Obama is on his way to Alaska to promote global warming alarmism. I have been to Fairbanks in January, and all I can say is: if more atmospheric CO2 can raise the temperature there by 0.7 degree, it isn’t nearly enough!