"Propagation of Error and the Reliability of Global Air Temperature Projections"

"The reliability of general circulation climate model (GCM) global air temperature projections is evaluated for the first time, by way of propagation of model calibration error. An extensive series of demonstrations show that GCM air temperature projections are just linear extrapolations of fractional greenhouse gas (GHG) forcing. Linear projections are subject to linear propagation of error. A directly relevant GCM calibration metric is the annual average ±12.1% error in global annual average cloud fraction produced within CMIP5 climate models. This error is strongly pair-wise correlated across models, implying a source in deficient theory. The resulting long-wave cloud forcing (LWCF) error introduces an annual average ±4 Wm–2 uncertainty into the simulated tropospheric thermal energy flux. This annual ±4 Wm–2 simulation uncertainty is ±114 × larger than the annual average ∼0.035 Wm–2 change in tropospheric thermal energy flux produced by increasing GHG forcing since 1979. Tropospheric thermal energy flux is the determinant of global air temperature. Uncertainty in simulated tropospheric thermal energy flux imposes uncertainty on projected air temperature. Propagation of LWCF thermal energy flux error through the historically relevant 1988 projections of GISS Model II scenarios A, B, and C, the IPCC SRES scenarios CCC, B1, A1B, and A2, and the RCP scenarios of the 2013 IPCC Fifth Assessment Report, uncovers a ±15 C uncertainty in air temperature at the end of a centennial-scale projection. Analogously large but previously unrecognized uncertainties must therefore exist in all the past and present air temperature projections and hindcasts of even advanced climate models. The unavoidable conclusion is that an anthropogenic air temperature signal cannot have been, nor presently can be, evidenced in climate observables."

https://i2.wp.com/wattsupwiththat.com/wp-content/uploads/2019/09/clip_image002.png

https://www.frontiersin.org/articles/10.3389/feart.2019.00223/full

Will wait for responses.

This subject is too technical for denizen lee who cannot offer a glib one-liner of nonsense.

There is a critical response from Dr. Patrick Brown:

https://youtu.be/rmTuPumcYkI

https://patricktbrown.org/2017/01/25/do-propagation-of-error-calculations-invalidate-climate-model-projections-of-global-warming/


Quote:

... This list is not exhaustive, but in-and-of itself is sufficient to vitiate the analytical merit of Dr. Brown’s analysis, in its entirety. Now to specifics: Dr. Brown’s critique was presented under five headings: 1. Arbitrary use of 1 year as the compounding time scale. 2. Use of spatial root-mean-square instead of global mean net error. 3. Use of error in one component of the energy budget rather than error in net imbalance. 4. Use of a base state error rather than a response error. 5. Reality check: Hansen (1988) projection. These are taken in turn in subsequent posts. I assume any readers are familiar with the contents of Dr. Brown’s video. ...

Laugh till you cry wrote on Sep 9^th, 2019 at 4:48pm:

This subject is too technical for denizen lee who cannot offer a glib one-liner of nonsense.

Poor petal. Quoting an old paper and sells it as new. ;D ;D ;D ;D ;D ;D ;D ;D

The paper has passed peer-review. ;)

So give us your interpretation of it lee.

Just cutting and pasting an article without any commentary is pure laziness (or ignorance)

The_Barnacle wrote on Sep 10^th, 2019 at 4:34pm:

So give us your interpretation of it lee. Just cutting and pasting an article without any commentary is pure laziness (or ignorance)

You are the expert. You tell us where you think it wrong. ;D ;D ;D ;D ;D

But basically it shows the climate models are pure unadulterated crap.
RCP8.5  is pure crap.

Bu tell me where I got it wrong. ;)

lee wrote on Sep 10^th, 2019 at 5:15pm:

The_Barnacle wrote on Sep 10th, 2019 at 4:34pm: So give us your interpretation of it lee. Just cutting and pasting an article without any commentary is pure laziness (or ignorance) You are the expert. You tell us where you think it wrong. ;D ;D ;D ;D ;D But basically it shows the climate models are pure unadulterated crap. RCP8.5  is pure crap. Bu tell me where I got it wrong. ;)

Out with it man! Put it on the line!

You got it wrong because you don't understand any of it enough to discuss it.

Laugh till you cry wrote on Sep 10^th, 2019 at 5:20pm:

Out with it man! Put it on the line!

Says the man who quoted the critique of the wrong paper. ;D ;D ;D ;D ;D ;D

lee wrote on Sep 10^th, 2019 at 5:15pm:

The_Barnacle wrote on Sep 10th, 2019 at 4:34pm: So give us your interpretation of it lee. Just cutting and pasting an article without any commentary is pure laziness (or ignorance) You are the expert. You tell us where you think it wrong. ;D ;D ;D ;D ;D But basically it shows the climate models are pure unadulterated crap. RCP8.5  is pure crap.

Show me where it shows that
You love making demands on other people but are strangely reluctant to actually state a position on anything.

And so far the models are doing quite well. Including the first radiative-convective numerical model developed by Manabe and Wetherald in 1968 (height of the so-called mid century ice age scare.) It is still predicting temperatures quite well.

---

The_Barnacle wrote on Sep 15^th, 2019 at 1:01pm:

Show me where it shows that

Poor petal. Can't even think for himself

RCP8.5 is the highest scenario.

It seems in Climate Science^TM that as opposed to other disciplines which give low, business as usual, and high scenarios, gives ultra low, low and business as usual scenarios.

"Based on this analysis, we find that supply constraints on total fossil fuels production are likely to provide an upper-bound to climate change over the time horizon considered in this paper (out to the end of 2100). Specifically, based on the SD-PCU
emissions scenario, the median atmospheric CO2 concentration, and global-mean surface temperature increase, are likely to reach about 610 ppm and 2.63 C respectively by 2100, even when the rapid growth in the production of the nonconventional fossil fuels (specifically, oil and gas) is considered. Note that these results are significantly lower than those rojected by the IPCC under its earlier high-emission scenarios, such as SRESA1FI, or in its later high-concentration pathway of RCP8.5. Therefore, we conclude that the IPCC is likely to be overestimating the upper-bound of possible climate change over this time horizon; where this conclusion is supported by most of the ‘peak fossil fuel production’ studies published after
the year 2000 that we examined."

http://sci-hub.tw/10.1016/j.futures.2016.04.007

RCP8.5 is crap. ;)

Poor petal. Go cry yourself to sleep about 8.5 then.

Jovial Monk wrote on Sep 15^th, 2019 at 2:37pm:

Poor petal. Go cry yourself to sleep about 8.5 then.

That was supposed to be a stinging comeback? ;D ;D ;D ;D ;D ;D

Not really. Just you are so upset about it you have cried about it several times just this year.

Jovial Monk wrote on Sep 15^th, 2019 at 3:14pm:

Not really. Just you are so upset about it you have cried about it several times just this year.

;D ;D ;D ;D ;D ;D ;D ;D

Keep trying dolt.

you can't even bring yourself to deny it. ;)

Oh well, keep crying yourself to sleep over it.