Bishop Hill Water, water everywhere
Jan 3, 2013 Climate: WG2 The Met Office is hot out of the blocks on the climate front this year, issuing the first "climate disaster" story of the year via the BBC's Roger Harrabin.
The frequency of extreme rainfall in the UK may be increasing, according to analysis by the Met Office.
Statistics show that days of particularly heavy rainfall have become more common since 1960.
The analysis is still preliminary, but the apparent trend mirrors increases in extreme rain seen in other parts of the world.
It comes as the Met Office prepares to reveal whether 2012 was the wettest year on record in the UK.
Given the apparently overwhelming drought risk in the South East of England - of similar magnitude to the Sahara apparently - we should probably be grateful for this rain. And while we're on the topic, let's not forget the Institute of Civil Engineers' report on water availability in the UK:
By the 2050s, summer river flows may reduce by 35% in the driest parts of England and by 15% for the wetter river basin regions in Scotland. This will put severe pressure on current abstractions of water.
This being the year of the IPCC's Fifth Assessment Report, I think we should expect a lot of this kind of thing in coming months.
Reader Comments (60)
@ rhoda:
Is it even disputed that this is programmed in? That GHE processes are not modelled, just a defined sensitivity range? The models ought not to be used to demonstrate that which they assume.
Well said. I put this point to a Met Office friend back in Feb '10, when he pronounced the models & subsequent temperature curve to be correct how then could I explain the two, & I pointed out to him that the model had to be programmed to show warming for ever increasing amounts of CO2 added to the atmosphere, to which he had no response!
The press release for the study is now on the Met Office web site:
http://www.metoffice.gov.uk/news/releases/archive/2013/2012-weather-statistics
Anyone clever who can work out the trend at 61, 62, 63 etc years? I bet it's a blatant cherry pick!
C4 News just covered the "announcement" by scientists that the weather has now definitely been affected by climate change as its top news item.
Though I note their website story is much less alarmist.
http://www.channel4.com/news/2012-second-wettest-year-on-record
FFS!
Dr Betts,
[waves]
Could you ask Dr Slingo to do the same extreme rainfall analysis for the period 1930 to 1950? Let me go out on a limb and predict that you will find a burst of extremer-than-usual rainfall events clustered from 1940 to 1947ish. My suggestion is that it is related to the blip shown in that period in the Mohmat 4.3 data set.
See http://i39.tinypic.com/2igd1mr.jpg
Here is my reasoning: if I understand the aerosol effect correctly than a deficiency of low level aerosols is leading to a raising of relative humidity within clouds. So it rains, when it gets round to it, more explosively, with bigger drops.
If her analysis shows the same effect in 40-47, come back and I'll tell you why.
JF
[rave, froth, etc]
The Ch4 news report was appalling - with repeated, unequivocal assertions that we can definately now say the wet weather is all due to 'climate change' over a backdrop of VT flood footage. Zero attempt to examine the historical record or put the data in perspective. Just a quick 1 second shot of a rising graph on someone's computer screen - with unreadable axis labels - probably a cherry picked period).
"The Ch4 news report was appalling"
Be warned the BBC are winding up to make this their lead at the 10pm news
CO2 levels were up to 15 times higher 500 million years ago...did we burn up or green up? We would not be here if doubling CO2 would cause us to burn up...it's called logic. As someone on WUWT just commented.....2012 was the 8,000th warmest year in the current Holocene..ha.
Spence_UK
It would be good to understand the reason for this difference. Possibly the following points might help, apologies if they are old news.
I understand that some analysis techniques struggle to detect fluctuations that decrease with time-scale. For example, difference and variance both suggest constant fluctuations for white noise whereas theory suggests they must decrease as Dt^(-1/2). Lovejoy's group says that Haar can detect decreasing fluctuations. You can see it also by simply smoothing the data.
A plausibility argument in support of the intermediate regime is as follows:
1/ In both GCMs and simple stochastic energy balance models (e.g. Collins et al and Vallis), fluctuations increase over short time-scales and then decrease ever thereafter. This underlies the flat IPCC description of natural variability.
2/ The large fluctuations back to the LGM mean that at some point the "flat description" must break down and be replaced by a picture of increasing fluctuations. This point of break down would correspond to Lovejoy's \tau_c.
Finally, if you’ve not seen this figure 2 on page 26, then it is worth a look I think.
They simply have too many metrix to choose from. As William Briggs recently pointed out, http://wmbriggs.com/blog/?p=6870 .
Wettest year, Wettest season, Wettest month, Wettest Summer, ect.
Coldest...
Dryest...
Windyest...
Calm, humid, cloudy, dusty, smoggy, foggy.... unlimited more.
Kinda meaningless in and of itsself without some attribution cause.