Met Office Claims About Extreme Rainfall Not Supported By Their Own Scientific Paper
By Paul Homewood
One of the claims made by the Met Office is that:
Last month, we published a paper showing that for the same weather pattern, an extended period of extreme UK winter rainfall is now seven times more likely than in a world without human emissions of greenhouse gases.”
But what do the facts tell us about extreme winter rainfall?
Taking the long running England & Wales Precipitation Series, there has definitely been a trend to wetter winters, yet most of this increase appears to have taken place before 1900.
We can see the same pattern if we look at the extremely wet winters.
None of the top 20 winters appear until 1834, and even then remain relatively rare until 1912.
Obviously we get the anomalous winter of 2013/14, but this is the only winter to make the list since 2000, except for 2001. In contrast 1912, 1915 and 1916 all appear, and shortly afterwards we get 1923, 1925 and 1930.
There is no evidence at all that extremely wet winters have become more common or wetter.
Whatever the Met Office have fed into their models, it bears no resemblance whatsoever to reality.
I thought I should take a look at the paper, which the Met Office links to, and this turns out to be our old friend, “Explaining Extreme Events of 2014 from a Climate Perspective”.
The section they refer to is Chapter 10, “EXTREME RAINFALL IN THE UNITED KINGDOM DURING WINTER 2013/14: THE ROLE OF ATMOSPHERIC CIRCULATION AND CLIMATE CHANGE”.
And what is the Chapter’s finding?
Extreme winter rainfall in the United Kingdom becomes eight times more likely when the atmospheric circulation resembles winter 2013/14, whereas anthropogenic influence is only discernible in extremes with a shorter duration.
In other words, the study found no evidence that the wet winter had anything to do with “climate change”, and everything to do with atmospheric circulation, essentially the jet stream.
And even the paper’s comment about anthropogenic influence is only discernible in extremes with a shorter duration is highly misleading, as the actual detailed text states:
Figures 10.2b,d,f illustrate the effect of human influence on extreme rainfall for synoptic conditions similar to 2013/14. The ALL [All Forcings incl AGW] and NAT [Natural] (high correlation) ensembles are not distinguishable for both DJF and R10x based on Kolmogorov–Smirnov tests (p values greater than 0.2). However, a minor (not statistically significant) shift to wetter conditions due to anthropogenic forcings is identified for R10x, translating to an increase in the chances of getting an extreme event by a factor of about seven.
[R10x is the the wettest period during the year over 10 consecutive winter days]
So the anthropogenic influence they claim to have found for shorter duration events, is not even statistically significant, and does not even appear in the high correlation tests.
It really is disgraceful for the Met Office to attempt to defend themselves by misrepresenting scientific papers.
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