By Frank Bosse
(Translated, edited by P Gosselin)
It sounds so simple: it is undoubtedly getting warmer in Central Europe, and this is leading to increasing droughts. If you take the last two summers, this seems to be confirmed. And just like that it was exploited by the media: There’s a strong link between past climate change and increasing drought.
“Climate change leads to drought,” wrote MDR “Wissen” in April 2020, and many examples of the hype could be given about two summers in a row that were too dry, let’s leave it at that. But is this true? Does the unmistakable signal of warming, which is man-made, really show an increasing trend in drought here and in Europe?
This paper by a team of 20 authors from meteorological institutes in Europe gets to the bottom of this question by evaluating really long-lasting observations between 1850 and 2018. One could take the easy way out, because the result is already in the short summary:
Results reveal a general absence of statistically significant long-term trends in the study domain…”
The results reveal the absence of statistically significant long-term trends in the area studied. The warming is a confirmed long-term trend, the allegedly increasing drought is not. This is astonishing. What have the authors done?
The authors use the “Standardized Precipitation Index” (SPI) as a scientifically recognized measure of the occurrence of droughts to examine the European region. For this purpose, they not only evaluate whole years, but also evaluate seasonally (3 months) the very carefully validated data. The evaluation valid for Central Europe can be found in the freely accessible “Supporting Information”:
Fig. 4: The paper’s Figure 6 of the supplement from Vicente-Serrano et. al (2020).
Trends “are statistically non-significant”
If one also sees an anthropogenic warming trend in the temperatures since about 1980, we are missing such a long-term trend in the drought index. Frequent very dry periods also occurred in the 1920s, 1940s and 1970s. The team of authors really wanted to know exactly and looked everywhere in Europe (except Eastern Europe) for long-term trends matching temperature developments for different time periods:
Figure 5: The geographical distribution of the evaluated station data for the period 1871-2018, source: Fig. 2 of the paper.
There are occasional trends at individual stations, but nothing significant over longer periods over larger areas. So the authors write in the summary:
With few exceptions, trends in droughts over Western Europe are statistically non-significant from a long-term perspective.”
Alarmist claims based on insufficient data
So why are all claims of climate-related droughts increasing in this country? Most of the time, according to the authors, these are based only on short-term observations using insufficiently validated data or areas that are too small.
Media are fibbing
With great meticulousness, the authors prove that these claims are not scientifically substantiated. Up to now, readers could plead ignorance when reading and hearing about “drought caused by climate change” in the media and elsewhere. But from now on, one can assume the media are fibbing.
The scientifically based facts indicate that the connection simply does not exist.
So if you as an enlightened reader read such nonsense soon again, then take a close look at the authors of such reports: They are probably are trying to take you for a ride.