A new paper published in Ecological Modelling finds climate sensitivity to doubled CO2 concentrations is significantly lower than estimates from the IPCC and climate models which “utilize uncertain historical data and make various assumptions about forcings.” The author instead uses a ‘minimal model’ with the fewest possible assumptions and least data uncertainty to derive a transient climate sensitivity of only 1.093C:
“A minimal model was used that has the fewest possible assumptions and the least data uncertainty. Using only the historical surface temperature record, the periodic temperature oscillations often associated with the Pacific Decadal Oscillation and Atlantic Multidecadal Oscillation were estimated and subtracted from the surface temperature data, leaving a linear warming trend identified as an anthropogenic signal. This estimated rate of warming was related to the fraction of a log CO2 doubling from 1959 to 2013 to give an estimated transient sensitivity of 1.093 °C (0.96–1.23 °C 95% confidence limits) and equilibrium climate sensitivity of 1.99 °C (1.75–2.23 °C). It is argued that higher estimates derived from climate models are incorrect because they disagree with empirical estimates.”
Otto et al find equilibrium climate sensitivity [over the next several centuries] is only ~1.3 times greater than transient climate sensitivity, thus the estimate of 1.093C transient sensitivity could be associated with as little as 1.4C equilibrium sensitivity, less than half of the implied IPCC central estimate in AR5 of ~3.3C.
Moreover, this paper does not assume any solar forcing or solar amplification mechanisms. The integral of solar activity plus ocean oscillations explain ~95% of global temperature change over the past 400 years. Including potential solar forcing into the ‘minimal model’ could substantially reduce estimated climate sensitivity to CO2 to a much greater extent.
- Empirical estimates of climate sensitivity are highly uncertain.
- Anthropogenic warming was estimated by signal decomposition.
- Warming and forcing were equated in the time domain to obtain sensitivity.
- Estimated sensitivity is 1.093 °C (transient) and 1.99 °C (equilibrium).
- Empirical study sensitivity estimates fall below those based on GCMs [Global Circulation Models].
Abstract
Climate sensitivity summarizes the net effect of a change in forcing on Earth’s surface temperature. Estimates based on energy balance calculations give generally lower values for sensitivity (< 2 °C per doubling of forcing) than those based on general circulation models, but utilize uncertain historical data and make various assumptions about forcings. A minimal model was used that has the fewest possible assumptions and the least data uncertainty. Using only the historical surface temperature record, the periodic temperature oscillations often associated with the Pacific Decadal Oscillation and Atlantic Multidecadal Oscillation were estimated and subtracted from the surface temperature data, leaving a linear warming trend identified as an anthropogenic signal. This estimated rate of warming was related to the fraction of a log CO2 doubling from 1959 to 2013 to give an estimated transient sensitivity of 1.093 °C (0.96–1.23 °C 95% confidence limits) and equilibrium climate sensitivity of 1.99 °C (1.75–2.23 °C). It is argued that higher estimates derived from climate models are incorrect because they disagree with empirical estimates.
I like Pamela Gray’s description of CO2. That puts it in perspective.
CO2 [“carbon”] is simply a non-issue. On net balance CO2 is harmless, and beneficial to the biosphere. There is no identifiable downside to adding more CO2 to the atmosphere. At both current and projected amounts, more is better. A slightly warmer world is good. A colder world is bad.
But the alarmist crowd cannot admit that, because then their entire argument — and the life work of many of them — becomes completely irrelevant. That’s gotta leave a mark.
So climate alarmists continue to sound their false alarm. Too bad for them that the planet does not agree. Even worse for them, the public is coming around to the skeptics’ view.
dbstealey says
At both current and projected amounts, more is better. A slightly warmer world is good
@dbstealey
Like an ostrich, you too are just putting your head in the ground, ignoring the damage that could befall all of us if global cooling continues {as it will}. You honestly do not have not a clue [about the relevant science] if you think that putting more CO2 in the air will make it warmer on earth.
HenryP,
I don’t call you an ostrich just because we have different views. I also don’t understand how your comment relates to mine. I wrote: a colder world is bad. What is your objection to that?
dbstealey says
http://wattsupwiththat.com/2014/07/23/new-paper-finds-transient-climate-sensitivity-to-doubled-co2-levels-is-only-about-1c/#comment-1693643
henry says
There is no AGW. There never was. It is [now] cooling naturally. Just go or live with it.
Hopefully the wheel will turn up again
some time ahead
do you have an opinion as to when it will start warming again?
HenryP commented
Once the Arctic starts to ice over again. As open arctic waters is the global cooling system.
Mi Cro
http://wattsupwiththat.com/2014/07/23/new-paper-finds-transient-climate-sensitivity-to-doubled-co2-levels-is-only-about-1c/#comment-1693654
@Mi Cro
Actually, you are right about that.
I wonder how it is that you know why?
HenryP commented
Open Arctic water radiates far more energy to space than it take in, and far more than an icy Arctic.
iirc you think this cause more precipitation/snow altering the albedo, which seems reasonable, but if I had to pick, I’d say that is a feedback to the already open water.
HenryP says:
There is no AGW. There never was.
That is only an assertion. Just as I routinely point out that there is no measurable, testable scientific evidence to support AGW, likewise there is no such evidence that decisively refutes AGW.
It is my understanding that AGW exists, but it is too small to measure. That view is shared by various people such as Prof Richard Lindzen and Anthony Watts. To assert that “there is no AGW” oversteps current scientific knowledge.
I am still waiting for a definitive measurement of AGW. So far, no one has been able to provide one. But that does not mean there is, or is not, AGW. Radiative physics provides a rational argument that CO2 causes some minor global warming. But the question has not been decisively settled either way.
~ the ostrich
dbstealey says
likewise there is no such evidence that decisively refutes AGW.
henry says
but there is. I found it myself.
On the bottom of my last table.
http://blogs.24.com/henryp/files/2013/02/henryspooltableNEWa.pdf
There is no room for any AGW in my equation. Natural warming and cooling is 100% natural.
Check the worry in my eyes if nobody put it in a paper
Dear Henry
Try this little experiment. Take a container and fill it with a litre of water. Note that you can see the bottom of the container because the water is transparent to visible radiation. Now add a few drops of milk to the water and stir. Now you will be unable to see the bottom of the container because the milk has increased the opacity to light of the water. The concentration of milk required to do this is less than 500 ppmv.
Alternatively, you could try a slightly riskier experiment and simply add 400 ppmv of arsenic oxide to your tea or coffee (suggestion provided by Craig Bohren)
I am retired and you are making a fool of yourself.
No they don’t. There may be slightly negative trends in some of the datasets but the trends are NOT significant. This again supports the low sensitivity hypothesis since we have low solar activity and cooler PDO anomalies – yet mean global temperatures are essentially flat (i.e. NO warming but NO cooling either).
Incidentally your own dataset sample of stations is garbage. Too many of your stations are concentrated in small regions, e.g. 33% of your SH stations are in South Africa. South Africa represents only about 2% of total SH land mass.
@Mi Cro
There is a cycle which we know to be true as the Gleissberg
87-88 years
e.g.
http://www.nonlin-processes-geophys.net/17/585/2010/npg-17-585-2010.html
[from various investigations] I have been able to establish where we are in that cycle,
comparatively speaking, i.e. we are now ca. 1925
we know from eye witness reports that in 1923 it was still melting ice up there
http://wattsupwiththat.com/2008/03/16/you-ask-i-provide-november-2nd-1922-arctic-ocean-getting-warm-seals-vanish-and-icebergs-melt/
If all goes well, and all planets arrive in time, global warming should start up again in 2038
You can figure the rest out for yourself
(1935-1950 was very cold)
John Finn says
1) There may be slightly negative trends in some of the datasets but the trends are NOT significant
2)Incidentally your own dataset sample of stations is garbage. Too many of your stations are concentrated in small regions, e.g. 33% of your SH stations are in South Africa. South Africa represents only about 2% of total SH land mass.
Henry says
1) Some? 4 global data sets against how many you have that goes the other way?
2) I explained the sampling technique at the beginning of the tables =longitude does not matter as we are looking at the change in K/annum
Get with it John, or stay in retirement.
HenryP,
Let’s just disagree, because I see nothing that decisively *refutes* AGW.
I have long said that AGW is too small to measure. And it is; no one has ever posted any measurements quantifying the fraction of a degree of global warming caused exclusively by the rise in anthropogenic CO2. Therefore, AGW remains a conjecture — only the first step in the hierarchy: Conjecture, Hypothesis, Theory, Law.
AGW is not a hypothesis, because a hypothesis must be able to make repeated, accurate predictions [that does not necessarily make all hypotheses valid; the Greeks epicycles accurately predicted the movement of planets, but that hypothesis was falsified by Kepler]. AGW has never made repeated, accurate predictions. For example, no climate model was able to predict the current halt to global warming for almost twenty years.
On the other hand, I do not see where your tables demonstrate conclusively that AGW cannot exist. I’ll stop now, because I am getting too close to agreeing with John Finn. ☺
~ the ostrich
@dbstealey
there is no noise in the data
everything is according to [a natural] plan
live with it
[perhaps you have a problem with the idea that everything goes according to a plan]
Water Vapour has very little influence in the higher, drier colder layers of the troposphere. Here CO2 is the only player (see emission spectra at the link below). As CO2 accumulates in these colder layers emission from the gas is reduced (as calculated by the S-B equation). This means there will be an imbalance, i.e. there will be more energy entering the system from the sun than there is energy leaving the earth’s climate system. To restore the energy imbalance the surface and lower atmosphere must warm.
See this article from Climate Audit,
http://climateaudit.org/2008/01/08/sir-john-houghton-on-the-enhanced-greenhouse-effect/
Scroll down to the upwelling spectrum graph (Fig 3) and note the CO2 funnel at the colder layers. Now read Steve McIntyre’s comments below the graph.
The large notch or “funnel” in the spectrum is due to “high cold” emissions from tropopause CO2 in the main CO2 band. CO2 emissions (from the perspective of someone in space) are the coldest. (Sometimes you hear people say that there’s just a “little bit” of CO2 and therefore it can’t make any difference: but, obviously, there’s enough CO2 for it to be very prominent in these highly relevant spectra, so this particular argument is a total non-starter as far as I’m concerned. )
Without CO2 there would be a lot less water vapour. The warmists are right about that.
John Finn commented
None of this matters, what matters to the surface is the surface it radiates to, and that surface is very cold, find yourself a IR thermometer and measure straight up under clear skies. It’s pretty cold when it’s hot and humid (only ~60F colder on a mid 90’s muggy day, and tonight when it’s clear and cold out (~50F) it’s going to be close to -40F)
Except there no sign of an increasing trend in surface precipitation or humidity.
Henry says:
You honestly do not have not a clue…
And:
…perhaps you have a problem with the idea that everything goes according to a plan…
Henry, the ‘problem’ I have is being attacked by you, simply because we do not agree 100%.
Also, Henry, you wrote earlier:
There is no man made warming. If it is there it is so small that man cannot even measure it.
That’s exactly what I have been saying: AGW is too small to measure. That does not mean that AGW exists, or doesn’t exist. It means that if it exists, AGW is too small to measure. I am nothing if not consistent.
~the ostrich
Greg Goodman:
At July 23, 2014 at 4:26 am you write
No. Lindzen & Choi were not “far off” from Idso.
In 1998 Idso had used a variety of methods which each provided a similar value for climate sensitivity to that later obtained in 2011 by Lindzen & Choi. Idso’s excellent paper can be read here
http://www.warwickhughes.com/papers/Idso_CR_1998.pdf
The common factor of the determinations of Idso with that of Lindzen & Choi is that they measured effects in the real world instead of constructing complex models.
Richard
UAH and GISS have do not have negative trends. In any case NONE of the trends are statistically significant. They are not even close to significance. In other words there is NO cooling.
It does matter. Tell us how you calculate the SH averages.
“A new paper published in Ecological Modelling finds climate sensitivity to doubled CO2 concentrations is significantly lower than estimates from the IPCC and climate models…”
______________________
As the abstract of the paper states, the rate of 1.093 °C per decade is the ‘transient sensitivity’ or transient climate response (TCR). Equilibrium climate sensitivity (ECS) is given as 1.99°C. IPCC AR5 assesses ECS as likely to be 1.5°C to 4.5°C.
Therefore, contrary to the above comment, ECS given in this paper is within the ‘likely’ range as assessed by the latest IPCC report.
Mi Cro says:July 24, 2014 at 1:37 pm
John Finn commented
[…] ” Without CO2 there would be a lot less water vapour. The warmists are right about that.”
Except there no sign of an increasing trend in surface precipitation or humidity.
I agree and might go a further to say the RH trend is negative.
http://i61.tinypic.com/2wp16vt.jpg
I am surprised by the debate between dbstealey and Henry P since this appears to be bluster about nothing.
Whilst my views are not important, I am more in the dbstealey camp, save that I accept AGW exists only to the extent that changes in land use affect climate on micro regional basis, eg., urbanisation, de-forestation, damming, large scale irrigation/farming practices.
As regards CO2 driven AGW, the jury is out; there is no convincing evidence that proves it, or disproves the existence of it.
I also have a slightly different view on its strength. What we can say, is the signal from CO2 driven AGW, if any, is so small that it cannot be detected by our best available and most sophisticated measuring devices. What does that mean? It means:
1. CO2 driven AGW may exist; or
2. CO2 driven AGW may not exist;
3. If the accuracy and precision of our measuring devices is small, the signal to CO2 driven AGW, if it exists is small at most (if it was large it would have been detected).
4. If the accuracy and precision of our measuring devices is large, the signal to CO2 driven AGW, if it exists may be large (of course in this scenario it could also be small).
So do we need to be concerned? There is only one scenario where there might be reason for some concern, and that is where the accuracy and precision of our measuring devices is large. In this scenario, we just do not know whether there is or is not a problem (and that is assuming that one is of the veiw that a relatively rapidly warming world is a problem – which in itself is another moot issue).
So it all boils down to, how large are the error bands in our best available measuring devices?
The warmists claim they are small, personally, I do not see the evidence for that, especially given the short time scale of the satellite data and ARGO buoy data.
Further to my last post, one should not overlook the strong evidence that CO2 lags temperature on all timescales, and therefore CO2 is a response, not a driver.
That fact, if true, does not mean that CO2 cannot be a driver, but it does make it very much more difficult to detect an anthropogenic CO2 driven temperature response and signal.
@John Finn
Let me show you my results for Alaska.
http://oi40.tinypic.com/2ql5zq8.jpg
10 stations showed an average downward trend of -0.055K/annum since 1998.
That is almost one whole degree down since 1998.
However, I only used one of these 10 stations in my sample. It is because I figured out the correct sampling procedure. The problem with most other data sets is that they are not properly balanced.
a) The amount of weather stations taken from the NH must be equal to the amount weather stations taken from the SH
b) The sample must balance by latitude (as close to zero as possible)
c)The sample must also balance 70/30 in or at sea/ inland
d) longitude does not matter, as in the end we are looking at the change in average yearly temps. which includes the effect of seasonal shifts and irradiation + earth rotates once every 24 hours. So balancing on longitude is not required.
e) all continents included (unfortunately I could not get reliable daily data going back 38 years from Antarctica,so there always is this question mark about that, knowing that you never can get a “perfect” sample
f) I made a special provision for months with missing data, not to put in a long term average, as usual in stats, but to rather take the average of that particular month’s preceding year and year after. This is because we are studying the changing weather patterns over time.
As an example here you can see the annual average temperatures for New York JFK:
http://www.tutiempo.net/clima/New_York_Kennedy_International_Airport/744860.htm
You can copy and paste the results of the first 4 columns in excel.
Note that in this particular case you will have to go into the months of the years 2002 and 2005 to see in which months data are missing and from there apply the correction as indicated by me + determine the average temperature for 2002 and 2005 from all twelve months of the year.
So, John, what I am saying is that most other data sets are garbage, because they are in imbalance, mostly the NH stations are over-represented. You can clearly see from my tables that that leads to a skewed picture, i.e. more warming. Only my data set is properly balanced. But, as always, every person is entitled to cherish and hoard their own garbage.
Note that the proposed mechanism for AGW implies that more GHG would cause a delay in radiation being able to escape from earth, which then causes a delay in cooling, from earth to space, resulting in a warming effect. It followed naturally, that if more carbon dioxide (CO2) or more water (H2O) or more other GHG’s were to be blamed for extra warming we should see minimum temperatures (minima) rising faster, pushing up the average temperature (means) on earth. I found / you will find that if we take the speed of warming over the longest period (i.e. from 1973/1974) for which we have very reliable records, we find the results of the speed of warming, maxima : means: minima at 0.034 : 0.012 : 0.004 in degrees C/annum. That is ca. 8:3:1. So it was maxima pushing up minima and means and not the other way around. Anyone can duplicate this experiment and check this trend in their own backyard or at the weather station nearest to you. In addition, I find the following trends in minimum temperature records over time: 0.004K/annum (from 1974), 0.007K/annum (from 1980), 0.004K/annum (from 1990) and -0.009K/annum (from 2000). Putting these values out against the time periods indicated, i.e. 40, 34, 24 and 14 years respectively, you get the acceleration/deceleration of warming. I was astonished to find on a random sample of 54 stations, balanced as per procedure HenryP, an absolute perfect curve, a quadratic function, with Rsquare=1. That means 100% correlation. If there were any man made warming at all, one would expect to see some chaos in that curve…..(i.e. somewhat less than 100% correlation). Note that the theory of AGW implies rising minimum temperatures, pushing up the mean average temperature. See graph at just below the minima table!
henryspooltableNEWa (click to follow link)
There simply is no man made global warming. If it exists it is so small as to be immeasurable and it is inconsequential to what nature dishes out.
HenryP commented
So, while you balance out based on selection of stations, I didn’t want to be accused of picking the station I wanted, so I broke the world up into smaller chunks, Continents, latitude bands, Bands 60 longitude degrees long, and the blocks (because they could be assembled into all of these with some work).
You’re free to download and use any of it, if you’d like, follow the url in my name.
74
Idso: A skeptic’s view of potential climate change
In addition, Ramanathan & Collins (1991), by the
use of their own natural experiments, have shown how
the warming-induced production of high-level clouds
over the equatorial oceans totally nullifies the green-
house effect of water vapor there, with high clouds
dramatically increasing from close to 0% coverage at
sea surface temperatures of 26°C to fully 30% cover-
age at 29°C (Kiehl 1994).
this sounds very much like what Willis has been saying in his articles in WUWT. that there is a dramatic increase in cloud cover in the tropics as temperatures climb past a certain threshold, that prevents warming past 30C.
@Micro
thanks.
You can chop it up like that, and [I think] that takes care of the 70/30 @sea/inland problem, but you must just make sure that your no. of nh stations = no. of sh stations and that total latitude (of all stations) balances out close to zero.
Longitude does not matter [in your sample] if you want to study a change in irradiation/temperature.
I see that the link to my tables in my comment to John Finn did not work
here it is
http://blogs.24.com/henryp/files/2013/02/henryspooltableNEWa.pdf
@dbstealey
you are sitting on the fence, and you like it there.
It is OK, for me, if you are comfortable there, and happy,
but to me it is not the same as being truthful and obedient to the Truth.
DBStealy:I do not understand why AGW would not qualify as a hypothesis. It puts warming attributable to increasing atm CO2 and predicts increasing temperatures with increasing CO2. This has not happened and thus the Hypothesis stands refuted by the data, it seems.