More than fifteen months ago I wrote the post “What of the Pause?”, where I tried to analyse the state of the global climate with a special focus on the interesting developments following the 2011/12 La Niña. I have also later discussed that particular time period here.
I have earlier pointed out the close connection between the SSTa in that central-eastern part of the narrow Pacific equatorial zone called “NINO3.4” and “global” SSTa over decadal time frames, how the former consistently seems to lead the latter in a tightknit relationship, firmly constraining the progression of global mean anomalies through time – flat (though with much noise) as long as the NINO3.4 signal remains strong enough to override (and/or control) all other regional signals around the globe, which most of the time it does.
I have then proceeded to show how “global warming” (or “global cooling”) only appears to come about at times when the influence of this tight relationship on the global climate is somehow offset by surface processes elsewhere, meaning outside the NINO3.4 region. This obviously doesn’t happen too often, because it would take a very powerful and persistent process to disrupt and even break the sturdy grip of the NINO3.4 region on the leash with which it controls the generally flat progression of global mean temps over time.
In fact, from 1970 to 2013 it evidently only happened three times. Which means that within these three instances of abrupt extra-NINO surface heat is contained the entire “global warming” between those years. Before, between and after, global temp anomalies obediently follow NINO3.4 in a generally (though pretty noisy) horizontal direction; no intervening gradual upward (or downward) divergence whatsoever.
With the year 2015 completed, I felt an update of this NINO3.4-global SSTa relationship was in order. Is there evidence of a new step as of late …?
My answer to this can only be: ‘It is still too early to tell.’ But interesting things have happened – and are indeed still happening – over the last two to three years, since about mid 2013:
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’:
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 →
“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.“
“It is extremely likely [95 percent confidence] more than half of the observed increase in global average surface temperature from 1951 to 2010 was caused by the anthropogenic increase in greenhouse gas concentrations and other anthropogenic forcings together.”
‘More than half.’ That sounds like a pretty conservative guess. Well, they end up going further than that. Much further.
What caused global warming over the last 60 years or so, according to the IPCC? Apparently, human ‘greenhouse gas’ emissions alone (100%):
“The best estimate of the human-induced contribution to warming is similar to the observed warming over this period … The observed warming since 1951 can be attributed to the different natural and anthropogenic drivers and their contributions can now be quantified. Greenhouse gases contributed a global mean surface warming likely to be in the range of 0.5°C to 1.3 °C over the period 1951−2010, with the contributions from other anthropogenic forcings, including the cooling effect of aerosols, likely to be in the range of −0.6°C to 0.1°C.”
That should be a net range of anthropogenic ‘contributions’ to the general global temperature rise between 1951 and 2010 of 0.6 to 0.7°C.
So, then, what did not contribute at all (0%) to that same general warming, according to the IPCC? Apparently, natural external factors like solar activity, and natural internal factors like ocean cycles:
“The contribution from natural forcings is likely to be in the range of −0.1°C to 0.1°C, and from internal variability is likely to be in the range of −0.1°C to 0.1°C.”
That should make up a total natural contribution to the general global temperature rise between 1951 and 2010 of exactly 0°C. Continue reading →
We have identified three steps in mean global temperatures since 1970: one in 1979, one in 1988 and one in 1998. These three steps alone conspicuously and remarkably contain the entire modern era ‘global warming’ observed to occur between the late 70s and the early 00s, a period of about 20-25 years, depending on how you look at it. This means that outside these three distinct and sudden upward jolts, there has been no discernable ‘global warming’ going on at all for the duration of at least the last 50 years.
So how, then, did these three prominent steps in global temperatures come about?
It has long been known that the climate regime (the general state, arrangement and operative processes of the coupled ocean/atmosphere condition) of the Pan-Pacific basin changed fundamentally and abruptly in 1976/77. Many studies have documented this. Something big happened in the Pacific Ocean that year. This ‘thing’ has been dubbed ‘The Great Pacific Climate Shift’ (GPCS). Continue reading →
It bores me to death ceaselessly having to argue against assertive warmist claims about effects, simply presupposed as real, but – unfailingly – never supported by observational evidence from the real world, of altogether hypothetical mechanisms whereby increasing amounts of CO2 in the atmosphere is said to somehow warm the surface of the earth by radiative means.
It is the perfect circular argument. The perfect corruption of the scientific method. They don’t have to find and show at all that their claimed mechanism is working as postulated, because they already know it does. In advance. It’s there. Behind ‘the natural noise’.
‘Discussing’ this topic with the warmists, on their preset terms, from their compulsively linear (that is, CO2-bound) world perspective, thus gives as much meaning as arguing about the biological link between unicorns and horses. Continue reading →