“The official Dutch weather service KNMI has – for years – published temperature data half a degree C too high,” says reader. “Now they have called for a media silence on the subject.”
This is a major discrepancy. A half a degree Celsius is almost a full degree Fahrenheit. And yet, the warnings of record warmth have been based on temperature differences in the mere hundredths of degrees.
The above article is in Dutch. Here is a full Google translation:
The KNMI has been seriously embarrassed by incorrect measurements of the most important weather station in our country, that of De Bilt. For years the thermometer gave an average half a degree too high. The institute even promulgated a genuine media silence.
Crisis consultation at the KNMI. Telephones remain unanswered. Spokespersons are sitting with their hands in their hair. The meteorological institute got rid of the ridicule and indignity of the Netherlands on Thursday after it became clear that the temperature measurements in De Bilt had been systematic next year. The weather station gave on average half a degree too warm. The station in De Bilt is the official indicator of whether there is a ‘tropical day’ or a heat or cold wave in our country.
” We have inserted media silence ”, it sounds on the other side of the line after questions about the cause of the error. ” We have no comment at all for the time being. ” And after a short silence: ” It’s a nice technical story and we consider how we can best explain things. ”
Meteorologists from competitor Meteo Consult have been seeing a number of years ago. that the temperature in De Bilt was consistently slightly higher than in nearby Cabauw, near IJsselstein. But questions about that did not yield anything. This summer that difference suddenly disappeared, and De Bilt always seemed to lag behind in recent years. Only when inquiring at the KNMI did the institute acknowledge that it had moved the thermometer.
“Before that time the equipment was close to a row of trees, so more in the lee,” says Ron Wiersma of Meteo. ” Now he is more in the open field, and that just slightly lowers the temperature. ”
In itself, says Wiersma, it is not at all special that a weather station is being moved. ” That happens often. Vegetation and buildings have more and more influence. Only it would have been nice if they had reported that. “”
It was also known among scientists that the measurement location in De Bilt was not representative, says professor of meteorology Bert Holtslag of Wageningen University. ” Too sheltered. The wind measurements had previously been influenced by the massive KNMI building and the trees. It is not a happy location. “
Scientific climate models do not need to be adjusted. ” It may have influenced the number of summer or tropical days purely statistically, ” says Wiersma. ” But for long-term calculations it has no effect. ”
Others perceive it less lightly. The PVV says it is ‘shocked’ by the error measurement and wants clarification from Minister Jacqueline Cramer of Environment. ” KNMI has for years argued that the temperature rise in the Netherlands is caused by the emission of CO2. How can they maintain that now that they have been measuring a temperature that is half a degree too high for years? “, PVV MP Richard de Mos also commented on websites, or whether global warming is the result of greenhouse gases “Everyone thinks that the predictions for climate change suddenly are not right,” says Professor Holtslag, “but that is not the case, our own measurements show that for eighty years.”
The KNMI is silent for now .
Thanks to Rudy Meiner for this info.