Commentary from Nature Climate Change, by John C. Fyfe, Nathan P. Gillett, & Francis W. Zwiers
Recent observed global warming is significantly less than that simulated by climate models. This difference might be explained by some combination of errors in external forcing, model response and internal climate variability.
Global mean surface temperature over the past 20 years (1993–2012) rose at a rate of 0.14 ± 0.06 °C per decade (95% confidence interval)1. This rate of warming is significantly slower than that simulated by the climate models participating in Phase 5 of the Coupled Model Intercomparison Project (CMIP5). To illustrate this, we considered trends in global mean surface temperature computed from 117 simulations of the climate by 37 CMIP5
models (see Supplementary Information).
These models generally simulate natural variability — including that associated
with the El Niño–Southern Oscillation and explosive volcanic eruptions — as
well as estimate the combined response of climate to changes in greenhouse gas
concentrations, aerosol abundance (of sulphate, black carbon and organic carbon,
for example), ozone concentrations (tropospheric and stratospheric), land
use (for example, deforestation) and solar variability. By averaging simulated
temperatures only at locations where corresponding observations exist, we find
an average simulated rise in global mean surface temperature of 0.30 ± 0.02 °C
per decade (using 95% confidence intervals on the model average). The
observed rate of warming given above is less than half of this simulated rate, and
only a few simulations provide warming trends within the range of observational
uncertainty (Fig. 1a).
Figure 1 | Trends in global mean surface temperature. a, 1993–2012. b, 1998–2012. Histograms of observed trends (red hatching) are from 100 reconstructions of the HadCRUT4 dataset1. Histograms of model trends (grey bars) are based on 117 simulations of the models, and black curves are smoothed versions of the model trends. The ranges of observed trends reflect observational uncertainty, whereas the ranges of model trends reflect forcing uncertainty, as well as differences in individual model responses to external forcings and uncertainty arising from internal climate variability.
The inconsistency between observed and simulated global warming is even more
striking for temperature trends computed over the past fifteen years (1998–2012).
For this period, the observed trend of 0.05 ± 0.08 °C per decade is more than four
times smaller than the average simulated trend of 0.21 ± 0.03 °C per decade (Fig. 1b).
It is worth noting that the observed trend over this period — not significantly
different from zero — suggests a temporary ‘hiatus’ in global warming. The
divergence between observed and CMIP5-simulated global warming begins in the
early 1990s, as can be seen when comparing observed and simulated running trends
from 1970–2012 (Fig. 2a and 2b for 20-year and 15-year running trends, respectively).
The evidence, therefore, indicates that the current generation of climate models
(when run as a group, with the CMIP5 prescribed forcings) do not reproduce
the observed global warming over the past 20 years, or the slowdown in global
warming over the past fifteen years.
This interpretation is supported by statistical tests of the null hypothesis that the
observed and model mean trends are equal, assuming that either: (1) the models are
exchangeable with each other (that is, the ‘truth plus error’ view); or (2) the models
are exchangeable with each other and with the observations (see Supplementary
Information).
Brief: http://www.pacificclimate.org/sites/default/files/publications/pcic_science_brief_FGZ.pdf
Paper at NCC: http://www.nature.com/nclimate/journal/v3/n9/full/nclimate1972.html?WT.ec_id=NCLIMATE-201309
- Supplementary Information (241 KB) CMIP5 Models
Nevermind 😉 I found what I was looking for concerning the authors. Is “Nature Climate Change” associated with the “Nature” journal?
Sleepalot says: @ur momisugly September 5, 2013 at 2:15 am
“Global mean surface temperature over the past 20 years (1993–2012) rose at a rate of 0.14 ± 0.06 °C per decade (95% confidence interval)1. ”
Bullshit.
>>>>>>>>>>>>>>>>>>
My thoughts exactly.
Anthony and his team of volunteers found problems with the US system. Since these two systems would be considered ‘Top of the Line’ the rest of the surface station data can only be a lot worse. A.J. Strata goes into an analysis of error in the temperature data based on information gleaned from the Climategate e-mails HERE.
Laurie said on September 5, 2013 at 2:34 am:
Sometime after Climategate, the previously well-respected journal Nature, while still somewhat respected, decided to divest itself of “climate science” and created the special Nature Climate Change journal, with the expected press release that this was done to highlight the global importance of the issue, give it the attention it is due, yada yada.
To search for published scholarly works, and from them discover the resumes of their writers, use Google Scholar: http://scholar.google.com/
The first name shows up as “JC Fyfe”. Looks like there’s two of them, one does biomedical. The other does climate science, here’s an example that was done for the American Meteorological Society (AMS):
Try Google Scholar for that and the other names.
Or perhaps it is because the models have CO2 as an agent of warming when it cannot do this.
kadaka
repeat the experiment with an infrared heater.
you may be able to heat the water slightly but you will find that the top layer absorbs most of the radiation and produces vapor in response – then the vapor absorbs the radiation and carries it off.
some numbers on that would make an interesting comparison
At the risk of repeating myself, in view of the admitted uncertainties in the global surface air temperature record, it is not at all clear how much, if any, global warming has taken place at the surface of the earth since about 1880.
http://lidskialf.blogspot.co.uk/p/global-warming-is-hoax-2.html
Nick Boyce:
Your post at September 5, 2013 at 3:05 am says in total
Yes, I know. Indeed, I have been hammering the point in many places for many years; see e.g.
http://www.publications.parliament.uk/pa/cm200910/cmselect/cmsctech/memo/climatedata/uc0102.htm
So, I care about the inability to determine global temperature at least as much as you do.
However, that is NOT relevant to the discussion in this thread.
The climate models attempt to emulate climate change as indicated by global temperature (whatever that metric means). But the paper being discussed reports that the models fail in that attempt.
This failure is important because all IPCC predictions and projections are based on outputs of the climate models. Therefore, if the models do not emulate climate change – and the paper reports that they don’t – then everything the IPCC says is wrong so needs to be ignored.
Discussion of the failings of global temperature determination would disrupt the thread from its important subject. It should be avoided however much you, I or anyone else cares about the travesty which is determination of global temperature.
Richard
richardscourtney says: @ur momisugly September 5, 2013 at 2:34 am
…I agree both your points except that your second point is even stronger than you express.
Actually the true but unstated finding is that the models do not work for any length of time.
This is implicit because of the LIA issue I mention….
>>>>>>>>>>>>>>>
In the light of the geologic past the whole edifice crumbles. This study talks of “Global mean surface temperature over the past 20 years (1993–2012) rose at a rate of 0.14 ± 0.06 °C per decade”
That is a STABLE Climate and we should thank God for it.
From NOAA:
(Note this not talking centuries but decades.)
How much of a ‘Warming?
Not only were this drastic changes in temperature but they still do not know what caused them.
These abrupt warmings also occur during Interglacials.
Again from NOAA.
Even at a factor of 2 to 3 smaller (of the 10–15 Kelvin amplitude) that still gives a 1 to 3 Kelvin change “in a matter of decades” a far cry from the ‘Catastrophic’ 0.14 ± 0.06 per decade the Warmists are bleating on about.
kadaka, you need to repeat this with an incandescant light heat source, and a dark base to the bowl, to verify that light cannot possibly heat water, as per another of the S*y Dr*gon rants.
gnomish says: @ur momisugly September 5, 2013 at 2:59 am
… repeat the experiment with an infrared heater.
you may be able to heat the water slightly but you will find that the top layer absorbs most of the radiation and produces vapor in response – then the vapor absorbs the radiation and carries it off.
some numbers on that would make an interesting comparison.
>>>>>>>>>>>>>>>>>>
Agreed.
A heat gun will ‘froth’ the water causing disruption of the surface boundary layer. (That type of disturbance is one of the arguments used by warmists to say the oceans absorb heat from CO2.)
Gail Combs:
re your post at September 5, 2013 at 3:45 am
http://wattsupwiththat.com/2013/09/05/statistical-proof-of-the-pause-overestimated-global-warming-over-the-past-20-years/#comment-1408442
I fear we may be straying too far from the important subject of this thread. However, without meaning to start a side-track in the thread, I write to stress the importance of your point for the benefit of others.
The D-O Events indicate that the Earth has two stable conditions (i.e. glacial and interglacial). Transition between them consists of rapid ‘flickers’ between the two states until the climate stabilises in one of them.
This is consistent with the climate system being chaotic and having (at least) two strange attractors.
If that indication is correct then the fundamental assumption used in the climate models is wrong. The models assume climate change is driven by forcings.
However, the climate system has varying thermal input and varying temperature during each year so it is never in equilibrium. And, therefore, it oscillates (e.g. global temperature rises and falls by 3.8°C during each year).
If the chaotic climate system is constantly seeking its nearest strange attractor while constantly experiencing a changing equilibrium then ‘forcing’ is not relevant to climate change.
Richard
An interesting and accurate description. I would like to see the push back from the warmists if the reality of your statement is shown to them.
117 simulations
114 high
3 on target
+ 0 low.
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Groupthink
This is what happens when you try to model 1/f noise believing it to be a signal.
As the IPCC kindly showed in their graph showing the frequency distribution of the temperature it is 1/f noise. Like “normal” noise this is completely random, but unlike normal noise although the value at any time is random, in 1/f noise there is a high correlation between successive time points.
So e.g. if it becomes “hot” … it stays hot (for a while). If it is cold … it stays cold and if there is a trend … it tends to stick around.
In other words to the naive academic who wants to mine data for their next paper … it is full of quirks that can be said to be “something” which are all just random noise.
The only reason they got away with it so long is that it takes so long for the climate to change … and before their bogus claims of finding “something” got tossed in the trash.
So, when this is all over, who’s going to take Gore to court for all the damages he has caused? I’d say that 200 million could pay off some coal miners and pay refunds for elevated electric bills people have been paying. I want to see people like Gore punished for all the lies they has been spewing. Take that Peace Prize away from him. It’s about time to take this country back.
Rich says: Surely if you’re modelling the climate you can’t say, “My model’s wrong because of internal climate variability” because that’s exactly what you’re supposed to be modelling.
The difference between what these academics do and what a professional engineer would do is simple. If the model is M(t) and the climatevariability funciton is V(t) or written E(t) = 1+V(t)
Then the academic view of the world is that
Temperature = M(t) x E(t)
Whereas for the engineer would see this as:-
Temperature = V(t) + M(t)
In essence there is almost no difference between these two, but the assumptions on which they are based lead to a very big difference. The academic, in their cosy out-of-touch world which only cares about curve fitting to data doesn’t need to worry about being sued if the “bridge falls down”. So they can assume that the model is right and can dismiss that awkward thing called “natural variability” ignore the errors in E(t) and with a wave of their hand magically assume they “averaged out” and ignored. (1/f noise doesn’t average out). In contrast the engineer (who deal with the real world where people die if they are not right) would start from the premise that nothing was known for sure unless or until they were confident they knew how big M(t)’s contribution was. This is in our culture: “expect the unexpected” … expect natural variability. So engineers who are trained to be cautious in real world situations (not ivory towers and grant applications) and who are drilled in the true meaning of “confidence” (models that don’t fail, bridges that don’t collapse, weather forecasts that aren’t disastrously wrong) … we want models which attain the engineer’s meaning of “confidence” and everything else is “natural variability”.
For the academic … “confidence” … is only a paper exercise that the curve fitted
This leads to two very different viewpoints:-
Academic Temperature = M(t) …. Global temperature is the model and confidence= “it fitted”.
Engineer = Temeprature = V(t) …. Global temperature cannot be modelled unless or until we are sure there is a model that works and confidence is your credibility at getting it right first time.
Note the “spin” in the linked Pacific Climate article summarizing the paper:
“Over long time scales, global climate models successfully simulate changes in a variety of climate variables, including the global mean surface temperature since 1900. However, over shorter time scales the match between models and observations may be weaker.”
Translation: “We’re still all going to burn up and die if we don’t drown first!”
RMB says:
September 5, 2013 at 12:31 am
Yes, but you can heat water with a stream of air with a dewpoint higher than the temperature of the water. And possibly with a wet bulb temperature greater than the water temperture.
Hint – if you see fog forming over an ocean, you can be pretty confident that realtively warm, moist air is advecting over the water surface and that moisture is condensing on the surface. That releases heat that warms the water, wave action mixes is downward.
The wet bulb temperature is a temperature that an air mass can bring water too by conduction and evaporation. The reason the heat gun doesn’t work well is due to the hot dry air evaporating the water surface.
Gail Combs says:September 5, 2013 at 3:56 am
gnomish says: @ur momisugly September 5, 2013 at 2:59 am
… repeat the experiment with an infrared heater.
you may be able to heat the water slightly but you will find that the top layer absorbs most of the radiation and produces vapor in response – then the vapor absorbs the radiation and carries it off.
some numbers on that would make an interesting comparison.
>>>>>>>>>>>>>>>>>>
Agreed.
A heat gun will ‘froth’ the water causing disruption of the surface boundary layer. (That type of disturbance is one of the arguments used by warmists to say the oceans absorb heat from CO2.)
Gail, isn’t the ‘normal’ state of the ocean surface ‘frothed’, due to wave and wind action?
1. When temperature anomalies are used, is the temperature of the reference period (which is subtracted from the reading to give the anomaly) also adjusted when the rest of the data are adjusted?
2. When it is stated that Earth is recovering from the Little Ice Age by getting warmer, where is the source of more heat and is it a long-term source (like a warmed ocean portion releasing heat) or is it a quick-changing source, like a radiation imbalance in the atmosphere?
I think it is weak to argue that the Earth is recovering from an LIA unless a mechanism is given, one that is consistent with measurements.
For those who query the actual temperature change in the last 20 years, do try the UAH or RSS satellite record. Note, however, that there is no compelling argument that temperatures taken from a Stevenson screen 2.5 m above the surface of the Earth should be the same as (not offset from) those from a satellite measuring microwaves from a thickness of oxygen some distance above the Earth.
Except no one’s claiming that there has been a “pause” for 20 years. Calling a rise in temperature at the rate of 0.14 ± 0.06 °C per decade sure doesn’t sound like a “pause”, although it could be termed a slowdown. And there it is. By cherry-picking the last 20 years, instead of the last, say 17 years, they can claim a “slowdown”. It’s a way of back-pedaling, and thus keeping their precious CO2-centric models alive for at least a while longer.
only one complaint…
“For this period, the observed trend of 0.05 ± 0.08 °C per decade is more than four
times smaller than the average simulated trend of 0.21 ± 0.03 °C per decade (Fig. 1b).”
it kinda pissante but… the rate is one fourth that of the average simulated trend…
you cant be four times smaller than anything… once you get to one time smaller, youre at zero.
just saying it cause its true.
uk banks were made to pay back customers for mis-sold policies.i trust the government will be paying us all back the 15% green energy tax we are currently paying,and the inflated vehicle tax for vehicles producing higher amounts of co2 ,along with the funding diverted from important research into cancer etc ?
is there any organised concerted effort in the US or the UK to petition government with the now constant stream of information falsifying the cAGW hypothesis ? if not ,it is time it was organised by ordinary citizens.
in the UK a petition with 100,000 signatories must be discussed in parliament. is there such a petition active at the moment ?
gnomish says:
September 5, 2013 at 2:59 am
That’s a completely different experiment.
What I expect will happen is that evaporation will occur and raise the dew point and wet bulb temperature of the air in the room (kitchen, a stove top was in use). We can ignore the wet bulb temperature as there is little wind. As the dew point goes above the water temperature, the water will begin to warm and conduction will transport heat downward.
A completely different experiment.
richardscourtney says:
September 5, 2013 at 1:03 am
——————————————————
It’s no lie. Voodoo priests that truly serve the tribal chief can devine a future that serves his interest, no matter what they have said in the past.