From the BBC, the concluding section of David Shukmans post following the briefing given by climate scientists in London a couple of days ago. Some long unanswered questions are going to have to be addressed soon. Like, if a negative phase of natural variation can overpower the radiative forcing of co2 for 20 years (1997-2017), why can’t it have added to it for 20 years (1977-1997)?:
Professor Rowan Sutton, of Reading University, said computer simulations or models of possible future climate scenarios often show periods of ten years with no warming trend – some even show pauses of 20-25 years.
And Professor Stephen Belcher, head of the Met Office Hadley Centre, said observations and models showed that on average there were – or would be – two pauses in warming every century.
I asked why this had not come up in earlier presentations. No one really had an answer, except to say that this “message” about pauses had not been communicated widely.
So where does this leave us, as greenhouse gases emissions keep rising but the temperature does not?
Dr Peter Stott, of the Met Office, pointed out that 12 of the 14 warmest years have occurred since the year 2000 and says that other indicators – like the decline in Arctic sea ice of 12.9% per decade and losses of snow cover and glaciers – still point to a process of manmade warming.
Bad maths
But what about another possibility – that the calculations are wrong?
What if the climate models – which are the very basis for all discussions of what to do about global warming – exaggerate the sensitivity of the climate to rising carbon dioxide?
Dr Stott conceded that the projections showing the most rapid warming now look less likely, given recent observations, but that others remain largely unchanged.
A Met Office briefing document, released at the briefing, says that, even allowing for the temperatures of the last decade, the most likely warming scenario is only reduced by 10% – so “the warming that we might have expected by 2050 would be delayed by only a few years”.
Overall, it concludes, the pause “does not materially alter the risks of substantial warming of the Earth by the end of this century.”
In other words, global warming is still on.
But until the pause can be properly explained, many people will take a lot of convincing – especially if the pause lasts longer than expected.
Tallbloke's Talkshop 
“Professor Rowan Sutton, of Reading University, said (some) computer simulations or models of possible future climate scenarios often show periods of ten years with no warming trend”
Sounds like the “Infinite monkey theorem”
Dr Peter Stott, of the Met Office, pointed out that 12 of the 14 warmest years have occurred since the year 2000
This must be one of the dumbest statements which keeps on being trotted out. If global temperatures were white noise, then it would be reasonable to expect warm years to be evenly spread through the historic record. As far as I’m aware no climate scientists believe that global temps are white noise, yet many of them still claim to be suprised that warm years are clustered together.
“Dr Peter Stott, of the Met Office, pointed out that 12 of the 14 warmest years have occurred since the year 2000.”
Yes, we are in a warm period similar to that experienced during during the Medieval Warm Period. The key is in the words. The Romans experienced their own warm period too, as did others before them. It shouldn’t take an Einstein to even ask if this might be due to natural variation, and not human emissions of carbon dioxide.
Is Dr Peter Stott being either dense, or duplicitous? His call. I suggest anyone who takes him seriously (*see note below) try this:
a) Walk to the summit of Kinder Scout in the Peak District.
b) Now walk a hundred metres in a random direction.
c) Check your altitude. Are you in the valley, or still on the top of Kinder Scout.
d) Repeat (b) and (c) several times.
e) What did you expect? Climate and weather temperatures work this way too.
*Yes, I’m talking to you Professor Steve Jones. Try to remember this the next time the BBC asks you to arbitrate on their poor understanding of science and their efforts to control it. I generally still like your books though. 🙂
And Professor Stephen Belcher, head of the Met Office Hadley Centre, said observations and models showed that on average there were – or would be – two pauses in warming every century.
Oh yeah, the ones that coincide with changes to the PDO and AMO. The ones their models have never been able to predict.
“Professor Rowan Sutton, of Reading University, said computer simulations or models of possible future climate scenarios often show periods of ten years with no warming trend – some even show pauses of 20-25 years.”
I checked Prof. Sutton’s “future climate scenarios” claim relative to the 23 individual CMIP5 climate model simulations posted on KNMI Climate Explorer and plotted in the graphic below. The CMIP5 models are those used by the IPCC in the AR5 second order draft:
Do the “future climate scenarios” defined by these 23 simulations “often show periods of ten years with no warming trend”? According to trend lines fitted to running ten-year periods after 2013 warming gradients of zero or less occur less than 2% of the time. There are no cases where the models “show pauses of 20-25 years”, or even come close.
And none of the 23 simulations replicates the standstill in warming since 1998 (max 0.42 degrees C/decade, min 0.07, mean 0.21).
Roger Andrews on July 26, 2013 at
5:58 pm…
According to trend lines fitted to running ten-year
periods after 2013 warming gradients of zero or less occur less than 2% of the time.
Roger it appears you have replicated this;
SPIEGEL: Do the computer models with
which physicists simulate the future climate ever
show the sort of long standstill in temperature
change that we’re observing right now?
[Hans von] Storch: Yes, but ***only extremely rarely***. At my institute, we analyzed how often such a 15-year stagnation in global warming occurred in the simulations. The answer was: in ***under 2 percent of all the times we ran the simulation***. In other words, over 98 percent of forecasts show CO2 emissions as high as we have had in recent years leading to more of a temperature increase.
http://www.spiegel.de/international/world/interview-hans-von-storch-on-problems-with-climate-change-models-a-906721.html
I can’t think offhand of any discipline where over 98% of output is/are wrong. Throwing spagetti at a wall would give the same results so claiming they are right in hindsight & hindcast and then wanting more spaghetti is not science but does reek of snakeoil sales. If over 98% of any product is wrong and any remainder is of junk worth (i.e. right answer by way less than chance+ as they cannot model natural processes) something is seriously wrong.
I have been trying to put my finger of what the behaviour reminds me of. I’m inclined to drug or gambling addiction, leaning to the latter – the MetO and their lucky warming pants. If Josh is reading….:-)
Craig M:
Thanks for the info. I did know that someone had come up with the under 2% number but couldn’t remember who it was.
My estimate of less than 2% for ten-year periods was also on the high side. The actual number was 1.1%, and for von Storch’s 15-year periods it was effectively zero.
I think someone should ask Prof. Sutton to produce the climate simulations he bases his claims on.
http://www.bbc.co.uk/news/science-environment-22948138
The UK’s recent run of damp summers could be down to a cyclical warming of the Atlantic Ocean, scientists and meteorologists have said.
At a gathering at the Met Office in Exeter, they suggested a 10- to 20-year pattern of Atlantic warming was shifting the jet stream, leading to washouts in six of the last seven summers.
The researchers said the location of the fast moving winds of the jet stream was critical to the UK’s weather.
David Shukman reports.
Roger Andrews,
I wonder the statistical significance
merited to the model runs at the time as now we are supposed to take them seriously and give them more money?
Would not these rogue run/noise be ‘managed out’/filtered out as the models were developed in time? No doubt perception bias and continued data mangling played a role in binning them at the time.
Craig M
I can replicate most climate model projections very closely on a spreadsheet using only greenhouse gas forcings and an assumed climate sensitivity as input. I’d be happy to run whatever additional projections the IPCC might need for the bargain basement price of $10,000 a run, which is a mere fraction of what they cost now. 😉
What is happening here is a Desperate attempt to keep the gig running until the lead players can reach the Safety Zone of Retirement. Notice that they All talk in terms of a Pause, and Never ponder (at least publicly) the possibility of a Drop in temperatures.