Why “GISTEMP LOTI global mean” is wrong and “HadCRUt3 gl” is right

Two renditions of global surface (land+ocean) temperature anomaly evolution since 1970:

compress-2 (4)

Figure 1.

The upper red curve represents the final 46 years of the temperature record most frequently presented to (and therefore most often seen by) the general public: NASA’s official “GISTEMP LOTI global mean” product. There is hardly any “pause” in ‘global warming’ post 1997 to be spotted in this particular time series. It is the one predictably trotted out whenever an AGW ‘doom and gloom’ activist sees the need to ‘prove’ to a sceptic that “global warming” indeed continues unabatedly and rub his face in it.

The lower curve in Fig. 1 is an altogether unofficial one. However, it should still be fairly familiar to most. It is the one having been consistently used by me on this blog to represent actual global surface temperature anomalies since ~1970. It is time to explain (and to show) why …

This particular curve is simply the now defunct UEA/UKMO land+ocean product “HadCRUt3 gl” with an en bloc downward adjustment of 0.064 degrees included from January 1998*. The “Pause” is here vividly seen as but one (albeit an extended one) of several plateaus in an upward, distinctly steplike progression of global temps since the 70s.

* I discussed here why this is a necessary adjustment.

Now, which one of these two renditions is more honest in its attempt to depict the actual “reality” of things? And which one is the result of simply inventing extra warming?

Let’s have a look.

The following analysis uses data acquired from KNMI Climate Explorer and WfT.


I will draw your attention to a remarkable circumstance. Continue reading

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“The Blob” and global SSTa since 2010

Global SSTa has really been ratcheting up now for a while. At the moment, the strong ongoing El Niño is doing most of the work, but there is no question that even this has been provided with a significantly elevated baseline from which to soar, a raised mean level seemingly establishing itself already years before the current El Niño started moving.

Well, it just so happens that this new level is higher than the old one by quite exactly 0.1 K. How can one tell?

Like this …

We noted and discussed already a year ago how the global lower troposphere has yet to respond to the conspicuous and mostly extratropical accumulation of surface heat in the NE Pacific basin starting in mid 2013.

Under the working hypothesis that this abnormal and persistent NE Pacific surface heat phenomenon (often simply nicknamed “The Blob”) is responsible for the entire 0.1K lift in the mean level of global SSTa since 2013, and positing that the lower troposphere has not yet responded to it, hence giving rise to the distinct divergence seen over the last couple of years between the “gl SSTa” and “tlt” curves, we lower the former en bloc by 0.1K from July 2013 onwards (yellow vertical line in Fig.1) and superimpose it on the latter: Continue reading

UAH need to adjust their tlt product

Update (March 9th) – Dr. Roy Spencer just gave an interesting response:

“yes, we have been aware of some spurious warming over land versus over the ocean after approximately 2000. Our version 6 dataset (now close to completion) will have most of that removed, although it looks like some of it is genuine.”

I guess we all just have to wait and see …



I have earlier noted a rather curious blocklike shift up in the UAH tlt (lower troposphere temperature) timeseries occurring abruptly some time in 2005. (There is most likely a similar – only downward – step at the same time in the RSS tlt timeseries; however, this post will not address this one.)

The 2005 shift seems very much to originate in the land portion of the UAH dataset. The shift can readily be seen here, but not at all in the oceanic portion, a situation which is quite unprecedented in the record – global land temps simply do not by any known natural mechanism all of a sudden jump out of step with the global ocean temps and then remain elevated high above thereafter:

Land vs. ocean, UAH

Figure 1. As you can see, something quite out of the ordinary happens in the UAH land curve in 2005. Continue reading

The “enhanced” greenhouse effect that wasn’t

Update (March 24th) at the end of this post – a kind of a response from Feldman.



There was much ado recently about a new paper published in ‘Nature’ (“Observational determination of surface radiative forcing by CO2 from 2000 to 2010″ by Feldman et al.) claiming to have observed a strengthening in CO2-specific “surface radiative forcing” at two sites in North America going from 2000 to the end of 2010 (a period of 11 years) of about 0.2 W/m2 per decade, and through this observation further claiming how they have shown empirically (allegedly for the first time outside the laboratory) how the rise in atmospheric CO2 concentration directly and positively affects the surface energy balance, by adding more and more energy to it as “back radiation” (“downwelling longwave (infrared) radiation” (DWLWIR)), thus – by implication – leading to surface warming.

In other words, Feldman et al. claim to have obtained direct empirical evidence – from the field – of a strengthening of the “greenhouse effect”, a result, it would seem, lending considerable support to the hypothesis that our industrial emissions of CO2 and other similar gaseous substances to the atmosphere has enhanced, and is indeed enhancing still, the Earth’s atmospheric rGHE, thus causing a warming global surface – the AGW proposition.

From the abstract:

(…) we present observationally based evidence of clear-sky CO2 surface radiative forcing that is directly attributable to the increase, between 2000 and 2010, of 22 parts per million atmospheric CO2.”

And,

“These results confirm theoretical predictions of the atmospheric greenhouse effect due to anthropogenic emissions, and provide empirical evidence of how rising CO2 levels (…) are affecting the surface energy balance.”

So the question is: Do these results really “confirm theoretical predictions of the atmospheric greenhouse effect due to anthropogenic emissions”?

Of course they don’t. As usual, the warmists refuse to look at the whole picture, insisting rather on staying inside the tightly confined space of their own little bubble model world. Continue reading

What of “The Pause”?

I have previously shown how global temperatures rose in three distinct and abrupt steps from the 70s to the 00s – one in 1979, one in 1988 and one in 1998 – and at all other times, not at all. These three steps occurred relative to the SSTa curve of the NINO3.4 region in the equatorial zone of the central-eastern part of the Pacific Ocean. Before, between and after the three steps, global temperatures appear simply obediently to follow NINO3.4 without any sign of a continued slow, but steady upward drawing away as if from a ‘steady rising background forcing’:

Warming steps

Figure 1.

My opinion on the much talked about “Pause” or “Hiatus” in ‘global warming’ still said to be going on (the considerable final, level stretch of the upper blue curve in Figure 1), is thus naturally coloured by this understanding of how global temperatures normally progress through time, as exemplified by the period from 1970 till today.

Within this perspective, the “Pause” is but one of many temperature ‘plateaus’ between sudden steps up or down (the last time it went down was back in 1964, before the ‘modern warming’). The relevant questions are: When did the last step occur? When will the next one take place? And will it go up? Or down?

At the present time, I would still maintain that the last well-established step in global temperatures happened in 1998, following directly in the wake of the mighty 1997/98 El Niño. Simply because not enough time has elapsed to be able to say anything for certain about more recent events.

But there are definitely a couple of things at work today that deserve some close attention. Continue reading

The pressing need for ever-upward temperature adjustments … A matter of life or death to the AGW hype.

In July I wrote a blog post where a strange and very conspicuous step change indeed in global mean temps relative to the trended AMO (North Atlantic SSTa), occurring across the 8-year period of 1963-70, was pointed out:

AMO

Animation 1.

As you can clearly see, the two curves generally follow each other in remarkable style all the way from 1860 till today, except for the relatively sudden and substantial global upward shift taking place across the last half of the 60s, being firmly established by the end of 1970. After this point, the curves are back to tracking each other to an equally impressive degree as before the shift, only now with the global raised 0.25 degrees above the North Atlantic.

So why this step change? How did it occur? Continue reading

‘Noise + Trend’?

Judith Curry just recently asked the following question in her blog post “The 50-50 argument”:

“So, how to sort this out and do a more realistic job of detecting climate change and (…) attributing it to natural variability versus anthropogenic forcing? Observationally based methods and simple models have been underutilized in this regard.”

There is a very simple way of doing this that people at large still seem to be absolutely blind to. To echo the words of ‘Statistician to the Stars!’ William M. Briggs: “Just look at the data!” You have to do it in detail. Both temporally and spatially. I have done this already here, here and here + a summary of the first three here. In this post I plan to highlight even more clearly the difference between what an anthropogenic (‘CO2 forcing’) signal would and should look like and a signal pointing to natural processes.

Curry has many sensible points. She says among other things:

“Because historical records aren’t long enough and paleo reconstructions are not reliable, the climate models ‘detect’ AGW by comparing natural forcing simulations with anthropogenically forced simulations. When the spectra of the variability of the unforced simulations is compared with the observed spectra of variability, the AR4 simulations show insufficient variability at 40-100 yrs, whereas AR5 simulations show reasonable variability. The IPCC then regards the divergence between unforced and anthropogenically forced simulations after ~1980 as the heart of the their detection and attribution argument. (…)

The glaring flaw in their logic is this.  If you are trying to attribute warming over a short period, e.g. since 1980, detection requires that you explicitly consider the phasing of multidecadal natural internal variability during that period (e.g. AMO, PDO), not just the spectra over a long time period. Attribution arguments of late 20th century warming have failed to pass the detection threshold which requires accounting for the phasing of the AMO and PDO. It is typically argued that these oscillations go up and down, in net they are a wash. Maybe, but they are NOT a wash when you are considering a period of the order, or shorter than, the multidecadal time scales associated with these oscillations.

Further, in the presence of multidecadal oscillations with a nominal 60-80 yr time scale, convincing attribution requires that you can attribute the variability for more than one 60-80 yr period, preferably back to the mid 19th century. Not being able to address the attribution of change in the early 20th century to my mind precludes any highly confident attribution of change in the late 20th century.

And Continue reading