Guest post by David M. Hoffer
IPCC reports AR1 through 4 were published in relative obscurity. ClimateGate and the emergence of the blogosphere as the primary forum for debate of the science and public policy intersection changed all that. AR4 in particular has been put under the microscope, and thoroughly discredited. It was laced with references to gray literature, claims that were known to be false, and written in a misleading fashion with important information that didn’t fit the narrative downplayed or omitted.
Knowing the level of scrutiny AR5 would receive, my expectation for some time has been that the IPCC would put considerable effort into maintaining their alarmist narrative while not completely bankrupting their credibility on the science. Near-term projections (2016-2035) being Chapter 11, where they have the most to lose the soonest, seemed to me to be the best place to see how they would handle things.
Indeed, Chapter 11 is literally laced with caveats. To be fair, some of them are legitimate. Volcanic eruptions for example, cannot be factored in because we don’t know if, when, where, or how big they might be. On the other hand, they go out of their way to say that their projections are predicated on a major reduction in aerosol emissions over the next few years. Perhaps they have legitimate reasons to expect this, but with countries like China, India and Brazil ramping up fossil fuel consumption at a rate that dwarfs western world consumption, I find that a bit less than likely. More amusing however is their repeated (and repeated, and repeated) admonition that their projections may not be detectable due to natural variability. Given that skeptics were mocked for pointing out that the temperature record to date is well within natural variability, I find it a bit disingenuous that they now want to use that same natural variability to shield their inability to clearly demonstrate the very effects that they have for so long insisted were dominant, urgent, and catastrophic.
But the IPCC’s efforts to shroud every projection in a cloak of bankruptcy protection caveats may well be part of their undoing. Their extensive efforts on this range from the amusing, to what may well turn out to be bombshell material. Here’s one example of the amusing side of their efforts:
There is high confidence that baseline surface ozone (O3) will change over the 21st century, although projections across the RCP, SRES, and alternative scenarios for different regions range from –4 to +5 ppb by 2030 and –14 to +15 ppb by 2100.
Can you imagine a financial expert getting on a news program and, with a straight face, saying that after exhaustive analysis he is highly confident that in a year’s time the NASDAQ will be either higher or lower? To be fair, I think they’ve poorly worded what they meant, but that’s hardly the only example. AR5 was leaked in the first place because of the way the issue of solar variance is handled. While this next excerpt from Chapter 11 is on the one hand amusing, the issue it exposes is more serious:
As discussed in Section 184.108.40.206.1, a recent satellite measurement (Harder et al., 2009) found much greater than expected reduction at UV wavelengths in the recent declining solar cycle phase. Changes in solar uv drive stratospheric O3 chemistry and can change RF. Haigh et al. (2010) show that if these observations are correct, they imply the opposite relationship between solar RF and solar activity over that period than has hitherto been assumed. These new measurements therefore increase uncertainty in estimates of the sign of solar RF, but they are unlikely to alter estimates of the maximum absolute magnitude of the solar contribution to RF, which remains small (Chapter 8). However, they do suggest the possibility of a much larger impact of solar variations on the stratosphere than previously thought, and some studies have suggested that this may lead to significant regional impacts on climate (as discussed in 10.3.1.1.3), that are not necessarily reflected by the RF metric (see 8.2.16).
Let’s try and summarize that:
1. Observational data suggests they got the physics completely backwards
2. Despite which they’re sure the amount of change is small….but
3. It may result in larger regional impacts than projected
Say what? They think they got the physics completely reversed, but we should still trust them that the order of magnitude is small, but allow that the impacts might be larger anyway? Just like the ozone projection, they’ve cloaked their wording in so many bankruptcy protection caveats that they won’t actually be outright wrong no matter what happens. As to what the actual effects are…. the only conclusion I can draw is that they don’t really know.
But this last example is, in my opinion anyway, the most egregious of them all. It relates to the climate models themselves. Using start dates such as 1960, they go into great detail explaining how well the models mirror actual observed climate indices up to the present. They then talk about a variety of techniques to make them more accurate, one of which is “initialization”. Without going into a lot of detail as to exactly what initialization is, here is one rather startling quote:
While there is high agreement that the initialization consistently improves several aspects of climate (like North Atlantic SSTs with more than 75% of the models agreeing on the improvement signal), there is also high agreement that it can consistently degrade others (like the equatorial Pacific temperatures).
I don’t know that any amount of bankruptcy protection caveats can get them off the hook on this one. But I have to hand it to them, they do try:
As discussed in 11.3.1, most of the projections presented in 11.3.2–11.3.4 are based on the RCP4.5 scenario and rely on the spread amongst the CMIP5 ensemble of opportunity as an ad-hoc measure of uncertainty. It is possible that the real world might follow a path outside (above or below) the range projected by the CMIP5 models. Such an eventuality could arise if there are processes operating in the real world that are missing from, or inadequately represented in, the models. Two main possibilities must be considered: 1) Future radiative and other forcings may diverge from the RCP4.5 scenario and, more generally, could fall outside the range of all the RCP scenarios; 2) The response of the real climate system to radiative and other forcing may differ from that projected by the CMIP5 models. A third possibility is that internal fluctuations in the real climate system are inadequately simulated in the models.
The fact of the matter is that when you adjust a model and as a consequence one part becomes more accurate and another part becomes less accurate (as did happen with their initialization techniques) that is compelling evidence that the model is suffering from exactly such problems. This is evidence that there are factors in the real world that are improperly modeled or missing entirely from the models. Given that in the same chapter the IPCC is admitting that they probably got the physics of solar variation wrong first by ignoring it entirely when they should not have, and then by including it but getting the sign of the effect completely backwards, that seems like a pretty obvious conclusion. In fact, Chapter 11 also suggests that the models are having a tough time with aerosols, Atlantic Multidecadal Variability, Pacific Decadal Variability, Interdecadal Pacific Oscillation and Walker Circulation.
In brief, the evidence that the models are getting the right answers for the wrong reasons is staring them in the face. The models can sort of kind of get the climatology right, but only for the years we already have data for. In brief, they can use 1960 data to get 2012 right, but only because we already know what the answer for 2012 should be, and the adjustments deliver it. When those same models try and make projections into the future, and then we wait a few years for the future to arrive (AR4 projections from 2007 for example are already looking way off for 2012) the matter becomes readily apparent. AR4 suggested that if no warming showed up for 15 years, the models were probably wrong. AR5 seems to provide even better evidence that they are, in fact, wrong, surrounding their projections with so many caveats that anything short of an ice age or spontaneous combustion could be said to fit within their error range.
Of course this isn’t the final draft. Only time will tell how they choose to handle these issues now that they are exposed. But the contrived nature and density of the caveats makes what they are trying to protect themselves from seem obvious.
Chapter 11 can be downloaded here (PDF)