Bad Weather Reports: ‘Deutsche Wetterdienst’ Exaggerates Precipitation Trend 7-Fold To Produce Alarm

Producing alarmist scenarios and visions of climate horror are in vogue today at various weather and climate institutions. For example a recent study has just come out warning that Western Antarctic Ice Sheet is on the verge of a “chain reaction to collapse” – due to warming of course. (Never mind Antarctic sea ice is at a record high for the date). Things are no different at Germany’s national weather service; Deutsche Wetterdienst (DWD), who seem to have problems telling the truth.

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Surprise! Original data refuses to back up DWD’s claims of wetter winters in Germany

By Sebastian Lüning and Fritz Vahrenholt
(Translated/edited by P Gosselin)

A dew days ago D. E. Koelle expressed some outrage at questionable statements made by the Deutsche Wetterdienst (DWD German Weather Service) at a press conference in March 2014. The dubious statements were about Germany’s historical temperature development and came across as being alarmist (see “German Weather Service Uses Manipulative Statistical Sleights Of Hand To Craft Warming“). The DWD also looked at other weather parameters at the event, like precipitation. On page 2 of its press release the DWD writes:

Winter in Germany has gotten 30% wetter since 1881
Climate change in Germany can also be seen in precipitation data. The DWD experts calculated a 10% increase for annual mean precipitation since 1881. If one considers only winters, the increase nationwide is almost 30%. For spring and autumn the increases are almost 12% and 9% respectively. In the summer months the mean precipitation amounts since 1881 have decreased 1.2%.”

Winters are getting wetter, so salvage whatever you can.

But hold on a second. Let’s take a look to see if there is any truth behind the DWD’s claim of winter floods. To do this we use the online precipitation data that the DWD provide themselves. The result is depicted below. The surprise is great: Winter precipitation (December-January-February, DJF) is currently only about 4.5% higher than the period around 1918 and the 30-year smoothed curve always goes up and down. Climate alarm!

Figure: Precipitation in Germany over the last 125 years. Data source: DWD. Chart: DH7FB

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Moreover, the chart shows a downward trend, which happens to coincide with Germany’s temperature trend over the last 15 years. The DWD is misleading and abusing the public trust.

[Note: 30% is the relative increase and is thus circa 7 times more than 4.5%]

 

3 responses to “Bad Weather Reports: ‘Deutsche Wetterdienst’ Exaggerates Precipitation Trend 7-Fold To Produce Alarm”

  1. DirkH

    “The surprise is great: Winter precipitation (December-January-February, DJF) is currently only about 4.5% higher than the period around 1918 and the 30-year smoothed curve always goes up and down.”

    Smoothed curve LOOKS like it’s a centered average (see maximum at 1918) – but in that case how did they produce values from 1999 to 2014??? Extrapolation used? Which one? Can’t find original graph.

  2. Frank

    The smoothed curve was produced with a “Loess Filter” 30-years. ( http://en.wikipedia.org/wiki/Local_regression ).

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