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« One for the vine | Main | Your life in their hands »
Wednesday
Jul182012

Extreme weather

An interesting article about the wet British summer comes to us from Michael Hanlon in the Mail.

 

Perhaps the most dramatic and visible impact of climate change to date has been the reduction in Arctic sea ice cover and, particularly, thickness, seen in the last 20 years or so. The ice grows back in winter of course but, the evidence suggests, each year (on average) perhaps a little thinner than before. This makes the North Atlantic a little warmer than otherwise, reducing the temperature gradient between Polar and Tropical air and hence taking some of the wind (literally) out of the jetstream’s sails.

So, the overall effect of global warming will be to make our summers cooler and damper. The trouble is, this contradicts what most of the computer models have been saying to date, namely that in Britain we can expect hotter, drier summers and milder, damper winters. I spoke to Kate Willett, a climate scientist at the Met Office who agrees that the picture is confusing. “Yes, this contradicts the model of wetter winters and drier summers,” she says. It is also true, she adds, that since 2007 Arctic sea ice levels have been exceptionally low but it is not true that the last five summers have been exceptionally bad – those of 2010 and 2011 were average or a little above average in terms of sunshine and temperature.

This is almost beyond parody, so I'm not even going to try.

Interestingly, Hanlon says that there is a consensus that weather will become more extreme in an warming world. Is this right?

 

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Reader Comments (109)

So the Met Office finally admits it hasn't a clue. Will it hand back the big bonuses and the money wasted on new computers to the taxpayers and get rid of hundreds of scientists who have been wasting their time and our money? Perhaps Richard Betts will be along shortly to provide some comforting words about the fine job the Met Office is doing.

Jul 18, 2012 at 9:38 AM | Unregistered CommenterPhillip Bratby

The level of denial on display has now reached IMHO anthropologically interesting levels.

Forecast: warmer, wetter winters; warmer, drier summers.
Outcome: colder, drier winters; colder, wetter summers.

In any normal walk of life, the outcome above would wholly discredit the forecaster who scored 0 out of 4

Jul 18, 2012 at 9:43 AM | Unregistered CommenterJustice4Rinka

Since no weather observation could prove or disprove global climate warming, I am surprised that there be "climate scientists" still making wild statements about the weather.

Jul 18, 2012 at 9:47 AM | Registered Commenteromnologos

The modellers haven't a clue and the propaganda is starting to fail:

1. The models magick 40% more energy. ~400% increased IR exaggerates the effect of trace CO2 when from fundamental physics there can be no CO2-AGW.

2. They offset it by exaggerated cooling: twice real optical depth of low level clouds; variable ‘aerosol indirect effect’ when the physics from Sagan is patently wrong,

3. Organised deception on blog sites by people portraying genuine enquirers as ill-informed, politically-motivated or ‘deniers’.

4. 'Extreme weather' designed to disguise ‘the World is not heating’. It has been caused by low solar magnetic field. Nature is giving us fine Olympic weather!

5. It's very difficult for proponents of truth to fight the propaganda because carbon-traders, banks, energy majors and politicians are seeking big money..

6. Establishments are now quietly investigating the corruption.

Jul 18, 2012 at 10:09 AM | Unregistered Commenterspartacusisfree

Looking at SREX, there is also the issue of what "extreme weather" actually is. I have a feeling the "extreme weather" mentioned in newspapers is extreme in terms of impacts more than climatologically.

SREX also says:

A changing climate leads to changes in the frequency, intensity, spatial extent, duration, and timing of extreme weather and climate events, and can result in unprecedented extreme weather and climate events. Changes in extremes can be linked to changes in the mean, variance, or shape of probability distributions, or all of these (Figure SPM.3). Some climate extremes (e.g., droughts) may be the result of an accumulation of weather or climate events that are not extreme when considered independently. Many extreme weather and climate events continue to be the result of natural climate variability. Natural variability will be an important factor in shaping future extremes in addition to the effect of anthropogenic changes in climate.

[...] Observed changes in climate extremes reflect the influence of anthropogenic climate change in addition to natural climate variability, with changes in exposure and vulnerability influenced by both climatic and nonclimatic factors

And this ought be framed:

Confidence in projecting changes in the direction and magnitude of climate extremes depends on many factors, including the type of extreme, the region and season, the amount and quality of observational data, the level of understanding of the underlying processes, and the reliability of their simulation in models. Projected changes in climate extremes under different emissions scenarios5 generally do not strongly diverge in the coming two to three decades, but these signals are relatively small compared to natural climate variability over this time frame. Even the sign of projected changes in some climate extremes over this time frame is uncertain. For projected changes by the end of the 21st century, either model uncertainty or uncertainties associated with emissions scenarios used becomes dominant, depending on the extreme

Jul 18, 2012 at 10:11 AM | Registered Commenteromnologos

"So the Met Office finally admits it hasn't a clue" - and about time!

Will they now finally admit that the same models do not have a hope in Hell of identifying any possible effects of increasing concentrations of atmospheric CO2 over decadal timescales? (And please, no more nonsense about Lorentz attractors).

Jul 18, 2012 at 10:12 AM | Unregistered CommenterRoger Longstaff

Wow, Daily Mail in interesting-and-nuanced-climate-change-story-shocker.

Why is this beyond parody? You're seeing a genuine scientific uncertainty, worked through in real time. If you read any of the literature and reports on the future climate of the British Isles, you'll see a healthy dollop of uncertainty in there. The fact is, that climate change on small spatial scales is more uncertain. We'll learn more about individual processes that are important to us here in the UK (or anywhere, in fact) as we go along.

Andrew, I'm surprised that for one who seems so confident that climate change is no problem, you are happy to proclaim your ignorance on the science of extremes. You'll find the SREX report a good read - the uncertainty language is much better than the previous IPCC reports, and you'll probably like the conclusions too.

http://ipcc-wg2.gov/SREX/report/

Doug

Jul 18, 2012 at 10:16 AM | Unregistered CommenterDoug McNeall

[snip o/t]

Jul 18, 2012 at 10:23 AM | Unregistered Commenterspartacusisfree

Two initial comments on this:

First, Arctic sea ice has not been exceptionally low since 2007. Historical evidence suggests it was just as low in the 1920-30s and during periods in the 19th century.

If Kate Willett thinks that summer 2011 was above average in terms of sunshine and temperature then she must be referring to the stats for England, not the UK and especially not Scotland, where gardeners struggled to get anything except tatties to grow, such that I heard it described as the "year without a summer".

I do not buy this Arctic Ice => jet stream thesis at all. As I have commented before, Arctic temperatures have been average or below average since April, and before that sea ice extent was at record levels (for the satellite era). So how can milder air from the Arctic be affecting the track of the jet stream if the Arctic temperatures have NOT been mild? This is just another example of gonzo climate science, where the proponents have such closed minds that they no longer look at the actual data before devising a theory which fits in with their CO2 religion.

Jul 18, 2012 at 10:26 AM | Registered Commenterlapogus

Doug - I quoted SREX explicitly saying natural variability will triumph over emission-related changes for at least two or three decades. Then the Met Office pops in to forecast the past and make up another just-so-story this time about Arctic sea ice and the jet stream right now.

Yes, that IS a parody of the science, a parody committed by the Met Office.

Jul 18, 2012 at 10:40 AM | Registered Commenteromnologos

spartacus - you're sliding into Zed territory there, if not mental anguish and lack of health. Enough! Enough! Enough!

Jul 18, 2012 at 10:43 AM | Registered Commenteromnologos

Ommmm,,,ommmmm....ommmmm.

Jul 18, 2012 at 10:48 AM | Unregistered Commenterspartacusisfree

Doug

It's the sudden shift from wet winter, dry summer (UKCIP) to dry winter, wet summer (trying to link jetstream to AGW) that makes me laugh. You mustn't forget that spending decisions are being driven by UKCIP (see recent ICE report on water management).

Jul 18, 2012 at 10:50 AM | Registered CommenterBishop Hill

Bish - the absolute failure of understanding that SREX's like all other IPCC pronouncements are NOT for the here-and-now but for decades and decades hence, is no laughing matter.

I have blogged a few months ago about how the "wetter" projections for East Africa in 2080 were taken by international agencies as "wetter" forecasts for the 2010's, resulting in famine and many deaths. It was also a point made by Chris Funk in a column in Nature on Aug 3, 2011.

Jul 18, 2012 at 11:05 AM | Registered Commenteromnologos

The claim that a warming climate increases 'exceptional' weather is refuted by historic record. It is the cooler periods that had the severest storms, most rain etc. The Roman Warm Period was warm enough to grow red grape varieties north of York but towards the end of the Roman occupation of the UK, 400AD, the climate was cooling, wetter, stormier. The Dark Ages was a miserable time of cold and famine.

Jul 18, 2012 at 11:36 AM | Unregistered CommenterJohn Marshall

So, average Winter, cold Winter, mild Winter all Global Warming. Hot Summer, wet Summer, average Summer again all Global Warming. I think I see a pattern emerging here. All we need now is some actual Global Warming.

Jul 18, 2012 at 12:18 PM | Unregistered Commenter3x2

About a year and a half ago there was a post about the weather in the UK during Charles Dickens lifetime over at WUWT. The theory was that this would've been consistently cold and grim, like the way they were in Dickens stories. An analysis of records show however that even though this was a cooler period than now there were both very warm and very cold years. http://wattsupwiththat.com/2010/12/05/has-charles-dickens-shaped-our-perception-of-climate-change/ it's worth a read.
I am of the mind that during warm periods of the PDO you get more zonal flow and consistent weather but when thePDO goes cold, you get higher north south amplitude in the jet stream so much more variability in the weather. The arctic melting is only occurring on the Atlatic side and is likely due to the warm AMO. I suspect that when the AMO goes into its cool phase, the ice on the Atlantic side will come back as its done before. Russian fishing records have tracked this for over 150 years through 2 AMO cycles.

Jul 18, 2012 at 12:44 PM | Unregistered CommenterSean

On Arctic sea ice:

MASIE-NH stands for the Multisensor Analyzed Sea Ice Extent – Northern Hemisphere. It is similar to the Sea Ice Index (SII) product in that it is easy to use and gives a graphical view of ice extent in various formats. However, it relies more on visible imagery than on passive microwave data, so the ice edge position will generally be more accurate than that of the Sea Ice Index.

The Sea Ice Index ice extent is widely used, but the edge position can be off by 10's or in some cases 100's of kilometers.

http://nsidc.org/data/masie/about_masie.html

Jul 18, 2012 at 1:01 PM | Unregistered CommenterJonathan Drake

It seems that CRU were told way back in 2000 that Met Office forecasts were not as good as Weather Action (Piers Corbyn) by one of the Agenda 21 Directors

email 2318

to Mike Hulme at UEA from Julian Jones, Director Vision21 (Glos. C. C. Agenda 21)

“I am very concerned by the strong correlations between UK Winter Rainfall and solar activity and the failure of the authorities to incorporate such data in their forward planning – we appear to be paying a bitter price for this here in Gloucestershire.

Your rainfall data had been previously been published to illustrate increasing UK rainfall due to Greenhouse Gas emission led Global Warming – there would appear to be a strong solar component to this also.

By failing to acknowledge this and incorporate this in our plans we are also failing to produce a cohesive argument for Sustainable Development – certainly as far as the petrol protesters are concerned!”

http://foia2011.org/index.php?id=2268

Mike Hulme passes the mail on the Tim Osborne to respond,

From Tim Osborne UEA to Julian Jones -

“Mike Hulme asked me to reply to your email (copied above). The possible link between solar variability and winter precipitation intensity is very interesting – one of the scientific reviewers of our paper in fact asked us to add some comments about it to our original scientific paper. We declined to do so…..Nevertheless, as more observational data and improved statistical analysis techniques become available, it is becoming increasingly obvious that solar variations are important. For temperature, many scientists now feel that natural solar variations were the main contributor to the early 20th century ,warming that occurred between about 1910 and 1950. The dramatic warming since 1980, however, cannot be explained by changes in solar output. So, the role of solar variability is starting to be acknowledged, though it cannot explain all changes, and is much more uncertain than the greenhouse effect….”

Julian Jones responds

“….I have also asked Weather Action at SBU to provide longer time series
correlations between solar activity and terrestrial weather related
factors. We have used WA forecasts for planning the arable farming on 2500
acres here in Glos for several years – and they have been of great benefit.
They seem to achieve similar accuracy to conventional forecasts at 5 days
range, yet are produced months ahead, and are usually best at showing
overall trends, as well as extreme storm events. I appreciate such
forecasts could be produced by purely mathematical means; but the WA people
seem very sincere in their claim that these forecasts are produced by
correlations with solar activity – and certainly those graphs I originally
sent you would indicate (well beyond the chance of coincidence) that such
links do exist….”

http://foia2011.org/index.php?id=4753


Shame they didn't take far more notice of the solar activity links sooner -

"one of the scientific reviewers of our paper in fact asked us to add some comments about it to our original scientific paper. We declined to do so….."

This whole exchange was highlighted by E.M.Smith in a post on the Climategate Mails when he was investigating the links with the Agenda 21 programme - something of an eye-opener for him!!

http://chiefio.wordpress.com/2011/12/18/foia-agenda-21/

Jul 18, 2012 at 1:19 PM | Unregistered CommenterMarion

There has indeed been significant over-confidence in the ability of current climate models to provide accurate regional forecasts of precipitation. In particular, the "hotter drier summers, warmer wetter winters" meme has got far too embedded in conventional wisdom.

This came from the UKCIP02 projections released in 2002, which used only a single model. The more recent UKCP09 projections used many models to try to give a better range of estimated changes that explored the uncertainties in future changes. In UKCP09, while the central estimate was still for a drying, the range included both wetting and drying - see table 4.5 in this report.

But even then, this only holds for the longer terms (several decades away). In the short-term, natural variability overrides the anthropogenic climate change signal anyway, as Ed Hawkins has written about.

In the recent Climate Change Risk Assessment, which is intended to inform adaptation policy, we did make clear that (a) the projected long-term trend in UK precipitation, especially summer precip, is highly uncertain, and that (b) natural variability is more important in the short time. The report on this is here, see figure 3.3 in particular.

In the CCRA, the top risks were to do with flooding - see the CCRA Governement Report and Summary of Key Findings.

Omnologos is absolutely correct that projections out the 2080s should not be used to inform decisions on responding to climate change / variability in the near term. Instead, we need to develop useful forecasting capability for the next few years and seasons. This is now the main motivation for ongoing development of climate models and for the ongoing analysis of climate data for the identification and explanation of any trends.

Jul 18, 2012 at 1:20 PM | Registered CommenterRichard Betts

I see that David Attenborough is weighing in on the weather = climate angle.

Sir David believes the washout summer may be down to climate change. As a credible explanation he points to research by the University of Sheffield which suggests melting Arctic ice has slowed the jet stream, causing it to break into loops which have ushered to the UK unseasonably cold and wet weather systems. And he is convinced humans are the main cause of this.

The full predictable dreichness (headlined "'This awful summer? We've only ourselves to blame...') "is at http://www.independent.co.uk/news/people/profiles/sir-david-attenborough-this-awful-summer-weve-only-ourselves-to-blame-7942405.html

Jul 18, 2012 at 1:21 PM | Unregistered CommenterRick Bradford

Richard Betts
The more recent UKCP09 projections used many models to try to give a better range of estimated changes that explored the uncertainties in future changes. In UKCP09, while the central estimate was still for a drying, the range included both wetting and drying - see table 4.5 in this report.

I prefer Patrick Moore's "We just don't know" sums up the situation in far fewer words :)

Or as an old shepherd I knew in Perthshire in the 50s & 60s used to say "Mebbes it will mebbes it won't"

Sandy

Jul 18, 2012 at 1:55 PM | Unregistered CommenterSandyS

Thank you Richard. If indeed "in the short-term, natural variability overrides the anthropogenic climate change signal anyway, as Ed Hawkins has written about" would you disagree with somebody who wrote that Met Office scientists blaming current weather events on climate change/global warming are not informing the public as well as they could?

Jul 18, 2012 at 1:57 PM | Registered Commenteromnologos

Richard Betts: unless I've got it very wrong, the 2009 Trenberth et. al. Energy Budget is based on an increase of energy [333-238.5] = 94.5 W/m^2 in the system, 39.6% of the real input energy [238.5 W/m^2], a rise in IR by 411%, a perpetual motion machine which exaggerates very low warming due to CO2 increase. There is no way such a model can predict climate.

What's worse, on thinking through the problem further, there can be no CO2-AGW; the reason is the well-known IR phenomenon of self-absorption plus another factor seen in analytical chemistry. Time for reality methinks.

Jul 18, 2012 at 2:02 PM | Unregistered Commenterspartacusisfree

Interestingly, Hanlon says that there is a consensus that weather will become more extreme in an warming world. Is this right?

The notion that higher temperatures will lead to more extreme weather is demonstrably wrong. As any meteorologist will tell you, weather is driven not by temperature but by temperature gradient.

For example, observational data from NASA reveal that Venus, the hottest planet in the solar system, has an average temperature of 464ºC and wind speeds of only 0.3 to 1.0 m/s.

On the other hand Neptune, the coldest planet, has a temperature of –218ºC and by far the strongest winds in the solar system – up to 580m/s.

A hotter Earth with minimal polar ice would have a a shallower temperature gradient between the poles and the tropics and so enjoy calmer weather.

If there's a consensus claiming otherwise it's just plain wrong.

Jul 18, 2012 at 2:06 PM | Unregistered CommenterScottie

"we need to develop useful forecasting capability for the next few years and seasons"

After a decade+ of propaganda and meaningless "climate science"... this is what you have to say?

Andrew

Jul 18, 2012 at 2:20 PM | Unregistered CommenterBad Andrew

Jul 18, 2012 at 1:57 PM | omnologos

I'd want to see the exact quote from the Met Office person.

They may have been talking about estimates of the changing likelihood of certain specific extremes, eg: the recent paper Explaining Extreme Events of 2011 from a Climate Perspective

Can you provide a link?

Jul 18, 2012 at 2:28 PM | Registered CommenterRichard Betts

In the Norwich Evening News 2 days ago was the following:
http://www.eveningnews24.co.uk/news/meteorologists_blame_the_jet_stream_for_east_anglia_s_miserable_summer_1_1446613

Even the UEA's Climactic Reasearch Unit can't understand why reality doesn't fit their computer models...

And Richard North reports on the ice which won't go away:
http://www.eureferendum.com/blogview.aspx?blogno=82922

Jul 18, 2012 at 2:32 PM | Unregistered Commenterdave ward

I don't know what happened there - try this shortened link instead:
http://tinyurl.com/c4rn9rr

Jul 18, 2012 at 2:38 PM | Unregistered Commenterdave ward

Justice4Rinka : "In any normal walk of life, the outcome above would wholly discredit the forecaster who scored 0 out of 4" Jul 18, 2012 at 9:43 AM

Correction: 2 out of 6

They correctly predicted there will be a winter and a summer.

Jul 18, 2012 at 2:43 PM | Unregistered CommenterGarry

"In the short-term, natural variability overrides the anthropogenic climate change signal anyway"


That's why, when the ice age restarts, the Met Office will be the last to know. Richard, who there is looking to see whether you are all wrong? Seriously now, not just token. This is the kind of thing which gets all organisations into trouble, closed-mindedness and resistance to unwelcome ideas.

Jul 18, 2012 at 3:04 PM | Registered Commenterrhoda

Richard, you guys really crack me up! When you can say with a straight face that the reason you got it wrong was that it was only one model and that with more models predicting more outcomes then you will have predicted it????? Well don't you guys just love to have your cake and eat it too. That is not predicting that is gaming the system. It is like saying you can predict a coin toss 100 times out of 100 with two models. One always predicts heads and one always predicts tails. F-ing genius, what a great way to do science. How about the truth and just tell the world the models are not simulating the real world as you are in the learning phase and that none of the climate models are valid.

Jul 18, 2012 at 3:06 PM | Unregistered Commenterhum

Re: Jul 18, 2012 at 2:02 PM | spartacusisfree

"Time for reality methinks"

Unfortunately the Met Office don't seem to do 'reality' they prefer their virtual world of climate models.

Back in the winter of 2010 for example when Julia Slingo Chief Scientist of the Met Office tried to tell us that the bitterly cold spell we were experiencing was a 'local' event (the third cold winter in a row that the Met Office had predicted would be 'mild')

"This is not a global event; it is very much confined to the UK and Western Europe and if you look over at Greenland, for example, you see that it's exceptionally warm there."

http://www.independent.co.uk/environment/climate-change/the-uk-may-be-cold-but-its-still-a-warm-world-says-met-office-chief-2165492.html

Except we didn't just "look over to Greenland"

we looked at the rest of the world, and what did we find -

unusually, snow at Christmas in Australia

http://phys.org/news/2010-12-australia-swaps-summer-christmas.html

Atlanta, with its first white Christmas since 1882

http://theglobalherald.com/usa-weather-atlanta-georgia-experiences-first-white-christmas-since-1882/8510/

people in Northern India 'reeling under intense cold conditions'

http://www.deccanherald.com/content/123129/cold-conditions-continue-northern-india.html

the authorities struggling to cope as huge snowdrifts made the streets impassible in St.Petersburg

http://news.smh.com.au/breaking-news-world/st-petersburg-icicle-patrol-fights-winter-hazards-20101224-1977d.html

4000 vehicles stranded on a freeway blocked by ice as severe cold swept southern China

http://www.beijingnews.net/story/720966

... so the cold we had in the UK wasn't quite so localised after all despite what our Met.Office told us!!!

Jul 18, 2012 at 3:10 PM | Unregistered CommenterMarion

@Richard unfortunately the models are just plain wrong

Last year I asked your boss, Professor Mike Lockwood, (at the Climate Change Conference at Downing College) why NOAA datasets showed no increase in atmospheric water vapour vapour, consistent with a water vapour "positive feedback"
All I got was arm waving and reference to the ridiculous wind-sheer proxy paper.

Now we have proof positive (see link below), that water vapour feedback is a non-starter- which nicely holes GCMs under (appropriately) the water line.

http://hockeyschtick.blogspot.co.uk/2012/07/new-paper-shows-ipcc-models-exaggerate.html

Jul 18, 2012 at 3:30 PM | Unregistered CommenterDon Keiller

Jul 18, 2012 at 1:20 PM | Richard Betts

Hi Richard,

You mentioned that "In the short-term, natural variability overrides the anthropogenic climate change signal."

When you mention "natural variability" here, are you referring to short-term weather variability i.e. occurring over a year or so, or are you referring to a longer term climate variability i.e. occurring over decades or centuries?

Thanks,
Philip.

Jul 18, 2012 at 3:42 PM | Registered CommenterPhilip Richens

Marion: if I were to tell you all the wrong physics, I would be immediately told off by the lackeys of the WWF. Suffice it to say, my present thinking about the GHE, which is that progressive reduction of band emissivity of the surface as GHGs enter self-absorption pushes up its temperature and the IR from it into the atmospheric window until you get a fixed GHE, is so left field they’ll be scratching their rumps for days.

Jul 18, 2012 at 3:53 PM | Unregistered Commenterspartacusisfree

Bishop, May I suggest you read this paper:
http://ddata.over-blog.com/xxxyyy/2/32/25/79/Leroux-Global-and-Planetary-Change-1993.pdf

Jul 18, 2012 at 4:02 PM | Unregistered CommenterTomRude

I understand that most of you are most interested in your abysmal UK weather (does it make you feel better to know that on the NW coast of NA, it is just about as bad? perhaps not).

However, regarding Arctic sea ice thickness mentioned in this article, I'd like to point out a few things that may be of interest from my own research. Most of this comes from a paper of mine on polar bears from 2008 available here http://scienceandpublicpolicy.org/originals/some_things_we_know_and_don_t_know_about_polar_bears.html

modified slightly and updated with more recent data below, with refs.

-A frequently cited reference regarding ice thickness (Lindsay and Zhang 2005) concludes that Arctic sea ice is experiencing a continual decline that cannot easily be reversed, but this is not a data-based paper ─ it is a model based on what is now considered old, substandard data from coastal submarine surveys.

- Many statements made regarding sea ice thickness in the Arctic do not acknowledge the incompleteness of this data: one frequently cited study (Laxon et al. 2003) surveyed (via satellite) only ½ of permanent sea ice and did not include ANY of the region in the central Arctic Basin (above 810 N).

- Sea ice thickness in the huge Arctic Basin region is based on very few actual measurements (taken from submarines in the early period) that have been extrapolated to represent the entire region and used in various climate models to predict future conditions (Rothrock et al. 2003; Yu and Rothrock 1996); the newest data, from electromagnetic sounding surveys done from aircraft in 2009, highlight the inadequacy of the long-term record (Haas et al. 2010);

Regardless of the fact that they are all we have got, these data are insufficient for assessing long-term trends. We do not have an accurate long-term measure of ice thickness.

Note: sea ice volume measures offered by PIOMAS (extent plus thickness) here http://psc.apl.washington.edu/wordpress/research/projects/arctic-sea-ice-volume-anomaly/
is another model, it is not a measure of actual total thickness.

Laxton, S., Peacock, N., Smith, D. 2003. High interannual variability of sea ice thickness in the Arctic region. Nature 425:947-950.

Lindsay, R.W. and J. Zhang. 2005. The thinning of arctic sea ice, 1988-2003: have we passed a tipping point? Journal of Climate 18:4879-4894.

Haas, C., Hendricks, S., Eicken, H., and Herber, A. 2010. Synoptic airborne thickness surveys reveal state of Arctic sea ice cover. Geophysical Research Letters 37:L09501, doi:10.1029/2010GL042652, 2010.

Rothrock, D.A., Zhang, J., and Y. Yu. 2003. The arctic ice thickness anomaly of the 1990s: a consistent view from observations and models. Journal of Geophysical Research 108(C3) 3083:28-1 – 28-10.

Yu,Y. and D.A. Rothrock. 1996. Thin ice thickness from satellite thermal imagery. Journal Geophysical Research – Oceans 101 (C11):753-778.

Jul 18, 2012 at 4:40 PM | Registered Commentersusanc

Here's in fact Peter Stott blaming some 2011 weather events on anthropogenic CO2 emissions:

http://www.telegraph.co.uk/topics/weather/9390338/Could-climate-change-be-causing-our-wet-summer-asks-Met-Office.html

Not exactly a straight quote, but almost:Dr Stott said recent ground-breaking work by the Met Office has once again proved that climate change is already having an impact on weather patterns across the world.

I am not sure how to reconcile Stott's "is already having" with Ed Hawkins' "in the short-term, natural variability overrides the anthropogenic climate change signal anyway".

Especially given the figures provided by Stott, eg "the second hottest November on record in the UK in 2011 was 60 times more likely than in the 1960s because of climate change".

SIXTY TIMES sounds to me like something MUCH GREATER THAN NATURAL VARIABILITY.

But I might be wrong.

Jul 18, 2012 at 4:47 PM | Registered Commenteromnologos

Jul 18, 2012 at 3:30 PM | Don Keiller

Hi Don

I thought that both satellite and radiosonde datasets showed a long-term increase in tropospheric water vapour, with the radiosonde datasets going back to the 1970s.

BTW Why do you say Mike Lockwood is my boss? He's at Reading University.

Cheers

Richard

Jul 18, 2012 at 4:49 PM | Registered CommenterRichard Betts

Jul 18, 2012 at 4:47 PM | omnologos

Thanks. In that article, Peter's quotes are about UK temperature and continental-scale precipitation, whereas here we are talking about UK precipitation. Trends in the latter are harder to detect, attribute and predict - precip is harder than temperature in general, especially at small scales.

Cheers

Richard

Jul 18, 2012 at 4:54 PM | Registered CommenterRichard Betts

May I also respectfully add that this further statement by Dr Stott is completely unwarranted, scientifically baseless and politically untrue:

“Our vulnerability to extreme weather is much greater than is used to be"

Dr Stott, I surmise, has zero qualifications on vulnerability analysis, however long studied his efforts have been on climate change, extremes and impacts.

Jul 18, 2012 at 4:55 PM | Registered Commenteromnologos

Ah, the adjusted radiosondes. 0.4 K per decade, hey? Really? What is the best place to look for water vapour figures? Why are we each cherry-picking papers when we ought to be finding out what is going on?

Jul 18, 2012 at 4:57 PM | Unregistered CommenterRhoda Klapp

Our comments crossed paths...are you saying that natural variability is on-par or smaller than the anthropogenic component, wrt temperatures?

Jul 18, 2012 at 4:58 PM | Registered Commenteromnologos

Jul 18, 2012 at 4:55 PM | omnologos

I agree that Peter seems to have used "vulnerability" incorrectly there. That is a socio-economic characteristic, not a meteorological one. I'll have a word to remind him to be careful about "vulnerability", "hazard", and "risk".

To be fair, I have probably made the same mistake in the past.

Jul 18, 2012 at 5:00 PM | Registered CommenterRichard Betts

Jul 18, 2012 at 4:58 PM | omnologos

Depends on the timescale and spatial scale. Globally, natural variability probably dominates over a few years to a decade or so, whereas the anthropogenic forcing probably dominates over several decades.

Jul 18, 2012 at 5:16 PM | Registered CommenterRichard Betts

"Depends on the timescale and spatial scale. Globally, natural variability probably dominates over a few years to a decade or so, whereas the anthropogenic forcing probably dominates over several decades."


So exactly how is your theory falsifiable? Absolutely any weather at all or lack of it fits neatly into your conditions. This is not very convincing. How about some measurements that mean something.?

Jul 18, 2012 at 5:30 PM | Unregistered CommenterRhoda Klapp

Hi omnologos, I was interested in the article with Stott arguing water vapour has risen 4% over 40 years. This shows different: http://wattsupwiththat.com/2012/07/18/new-paper-on-global-water-vapor-puts-climate-modelers-in-a-bind/

'This time series is devastating to the modeler’s** assumptions about the positive feedback of water vapor in a world with steadily rising CO2 levels.'

**They also apparently assume 40% increase of energy over reality, 400% in the IR, and offset it by twice real low level cloud optical depth and a variable net AIE based on Sagan's incorrect aerosol optical physics. I wonder which is true, modelling or experiment? I was taught the latter but I suppose Hansenkoism should be cut a little slack because it keeps the poor darlings in a job.

Jul 18, 2012 at 5:37 PM | Unregistered Commenterspartacusisfree

"anthropogenic forcing probably dominates over several decades"

There is no evidence at all to support this statement.

Jul 18, 2012 at 5:37 PM | Unregistered CommenterRoger Longstaff

@ Richard Betts

Come on, Richard. Fess up. All the forecasting the CAGW lobby does is designed to be falsifiable only after the forecasters have safely retired with their pensions, isn't it?

Jul 18, 2012 at 6:33 PM | Unregistered CommenterJustice4Rinka

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