Nature paper beating up “extreme rain” for the warmists
February 19th, 2011 by Warwick HughesA recent paper in Nature claiming an increase in extreme rain events 1951-1999 correlates with “AGW-climate change” has been given the usual uncritical acclaim in our GreenLeft media. I enjoy the originality in ABC headlines. Dr Roger Pielke Sr. has reviewed the paper.
I was surprised to see the Min et al paper only quote data for their “5 day consecutive rainfall” to 1999 – over a decade ago. Rainfall data must be in a worse state than I imagined.
I was curious to see what total rainfall data showed for the 20 to 60 degrees north band in the Northern Hemisphere –
Using data I can access at the KNMI Climate Explorer up to 2010, look under “Monthly observations.”
Running the linest function in Excel over the 60 years of GHCN rain 1951-2010 – the daily rainfall anomaly has increased by 0.00026mm PA which equates to 0.0156mm over the 60 year period – which in turn equates to an extra 5.69mm PA.
I seriously doubt anybody would notice a ~1% increase in their average rainfall over 60 years – but imagine the panic stories from the warmists if the climate were drying !!
Posted in Atmospheric science, Water | 4 Comments »
February 19th, 2011 at 10:50 am
(I’ll try that link again; if it doesn’t work then it’s available through the link Warwick gave above)
the paper Dam safety effects due to human alteration of extreme
precipitation by Faisal Hossain,Indumathi Jeyachandran,and Roger Pielke Sr.
pielkeclimatesci.files.wordpress.com/2010/03/r-351.pdf
is fascinating also; what layman would have thought that large dams effect increased precipitation; I’ve been advocating for more dams in the MDB system and this may be one reason to seriously consider that as opposed to water buy backs
February 25th, 2011 at 12:26 pm
Flannery mentioned the two papers in the Q&A discussion on the ABC. Willis Eschenbach at WUWT destroyed the Min et al paper here wattsupwiththat.com/2011/02/20/nature-unleashes-a-flood-of-bad-science/ and now he has knocked out the Pall et al paper here wattsupwiththat.com/2011/02/24/nature-magazines-folie-a-deux-part-deux/ . Willis indicates the Pall et al paper is about computer model output from data input of another model and has nothing to do with real data.
I think that Flannery read only the abstract conclusion and did not read the whole paper as unlike Willis he would be incapable of understanding anything about computer models and how they are written.
It is a disgrace that garbage papers such as these two (Min et al & Pall et al) are allowed to be published to fool people who are not capable of understanding. It is also a disgrace that an advisor to government on the scientific analyses of climate has zero capacity to understand research papers on the subject he is supposed to give advice.
In a comment on Willis’s post on the Min et al paper I said that the area rainfall in my area seemed to be a Poisson distribution as the standard deviation of the monthly rainfall was about equal to the average. One SD below the average brings the rainfall close to zero in any month which is not that unusual. The maximum rainfall in my area over 117 years is about 5 SD or 5* the average. This allows a probablity estimation of extreme rainfall but one needs a long record and even 120 years is not sufficient for one in hundred year estimation. Willis commented that the a modified Poisson distribution is more appropiate for extreme events
February 25th, 2011 at 1:29 pm
there’s an interesting article at Climate Conversation by Dr Vincent Gray The uncertainties of averages
www.climateconversation.wordshine.co.nz/2011/02/the-uncertainties-of-averages/
(this is probably more relevant to the post by Pat Franks which Warwick did but I can’t find it quickly – sorry Warwick)
February 25th, 2011 at 1:32 pm
Willis: “They used a single seasonal resolution atmospheric climate computer model (HadAM3-N144) to generate some 2,268 single-years of synthetic autumn 2000 weather data.
The 2,268 one-year climate model simulations of the A2000 autumn weather dataset were then fed into a second much simpler model, called a “precipitation runoff model” (P-R). The P-R model estimates the individual river runoff in SW England and Wales, given the gridcell scale precipitation.”
This is similar to what is being done in the CSIRO/BOM State Climate Initiatives – SEACI, SEQCI, there is also one in WA.
The technique they use is Downscaling. They take the IPCC Global Climate Models and use them to construct Regional Climate Models for regional Australia.
Computer models being used to create more computer models and this is then misleadingly sold to the public as “science”!!!
Pielke Snr asks why we are spending millions on Regional Climate Models when their results cant be verified:
Funding of multi-decadal regional climate predictions which cannot be verified in terms of accuracy is not only a poor use of tax payer funds, but is misleading policymakers and others on the actual skill that exists in predicting changes