McLean reveals IPCC confessions

John McLean is a PhD candidate, climate researcher, computer scientist and IPCC reviewer and lives in Melbourne. He has long made thoughtful and informed contributions to the debate on dangerous man-made global warming (DAGW). Two weeks ago I received a copy of a letter he had sent to the Dominion Post in Wellington concerning the spat between Carter and Leyland, Hot Topic and Wratt, Reisinger and Renwick (WRR). The letter contained startling revelations from the latest IPCC Assessment Report, AR5, and John kindly agreed I could publish them, though they’re new only to me. As far as we know the letter was not published. His letter takes its facts from an article he wrote for Quadrant Online last year. – RT

Oddly, NIWA scientists conceal them

UPDATE 1: 28 Mar 1300 NZDT, see below.

John’s letter refers to the WRR article Human role in climate change is clear. The following are excerpts from the AR5 then the WRR article (emphasis added). Notice the stinging observation that WRR failed to disclose what was inconvenient for the IPCC to say, because it contradicted the alarming sounds of doom.

Wratt, Reisinger and Renwick have all been closely involved with the IPCC so I ponder why their article failed to tell readers exactly what the latest IPCC report said, specifically:

1. “… the rate of warming over the past 15 years (1998–2012; 0.05 [–0.05 to 0.15] °C per decade) … is smaller than the rate calculated since 1951 (1951–2012; 0.12 [0.08 to 0.14] °C per decade).” [SPM, page 3, section B.1, and in full Synthesis Report on page SYR-6]

2. “… an analysis of the full suite of CMIP5 historical simulations (…) reveals that 111 out of 114 realisations show a GMST trend over 1998–2012 that is higher than the entire HadCRUT4 trend ensemble ….” [WGI contribution, chapter 9, text box 9.2, page 769, and in full Synthesis Report on page SYR-8]

3. “There may also be a contribution from forcing inadequacies and, in some models, an overestimate of the response to increasing greenhouse gas and other anthropogenic forcing (dominated by the effects of aerosols).” [SPM, section D.1, page 13, and full Synthesis Report on page SYR-8]

4. “This difference between simulated [i.e. model output] and observed trends could be caused by some combination of (a) internal climate variability, (b) missing or incorrect radiative forcing and (c) model response error“. [WGI contribution, chapter 9, text box 9.2, page 769]

So there are the dry, technical phrases of the AR5, but fortunately John gives it in ordinary language for us. Excerpts and summaries follow (my emphasis).

Let me summarise them in simpler terms; there’s no certainty that there was any warming over the 15 years prior to the writing of the report, but almost all climate models falsely predicted that warming would occur, with some “over estimating” the influence of greenhouse gases, and it’s not clear why so many models failed.

The IPCC report also says that the human influence on climate is estimated by running the models first with greenhouse gases and then without, and then attributing the difference in output to those man-made gases.

Given that the models falsely predicted warming when there was none and exaggerate greenhouse gases, any estimates of human influences on climate are extremely likely to be wrong. The IPCC can’t honestly say if there’s a big influence or a negligible influence.

John said that the claim that our three public climate scientists, WRR, made in the Dominion Post, saying “Warming of the climate system is unequivocal, and human influence on the climate system is clear” is misleading and doesn’t give the whole picture.

[Astonishingly, the three scientists have put these two statements side by side with the intention of misleading us. They fully expect most of us (and they’re right to expect it) will tell ourselves “human warming of the climate is clear” though the statements don’t say it, and human warming is insignificant — in fact, it’s so small it hasn’t been detected yet. — RT]

He advises us to seek evidence to support claims like these, distinguish clearly between fact and opinion, and avoid sweeping generalisations or vague correlations — regardless of which side of the climate debate makes them.

WRR said: “A substantial contribution to the observed increase in average global surface temperature since the mid-20th century has come from increasing greenhouse gas concentrations.” But then John McLean was astounded—as any scientist would be—to read:

There is no other plausible way to explain the observed changes.

He says that is not a proper scientific approach; and I say it’s not true. [UPDATE 28 Mar 1300 NZDT: WRR appear to assume that scientists fully understand every detail of the climate, which is patently untrue. Or perhaps they simply omitted a few trailing words — “as far as we know” or “to the best of our knowledge” — maybe even “as far as we’re prepared to look.” Choose for yourself, gentle reader.]

He himself published a paper in October that draws on various data to provide a very plausible explanation that leaves little if any warming to be blamed on greenhouse gases or anything else. [UPDATE 28 Mar 1300 NZDT: Using temperature, ENSO and cloud cover data, McLean shows that the average global temperature anomaly was possibly driven by the ENSO from 1950 to 1986, then to 1997 by a reduction in total cloud cover and then, to 2009, when the cloud data end, a decrease in low level cloud but increase in mid and upper level cloud. This explanation is a good fit for a temperature anomaly pattern that was flat from 1950 to 1976, rose slightly from 1977 to 1986, rose about 0.4°C from 1987 to 1997 and since then has been flat.]

It’s not a very technical paper and is freely available. He says it has been downloaded 2863 times and he hasn’t seen any comments that seriously dispute its findings. I’ve just checked and the number of downloads has gone up to 2895 (one of them is mine).

Have a look. Tell us what you think.

Visits: 173

12 Thoughts on “McLean reveals IPCC confessions

  1. Fantastic article. We’ve long known that there’s been intentional misleading of the public and politicians and so it is important that as many people as possible know what has been going on.

    It is simply dishonest to withhold vital information as they have done.

  2. Richard Treadgold on 28/03/2015 at 9:25 am said:

    Yes, this is public evidence of four specific omissions.

  3. Richard C (NZ) on 28/03/2015 at 11:51 am said:

    I’ve had a quick look at the McLean paper and while he cites some work on solar received at surface or Surface Solar Radiation (SSR), I think he’s overlooked the important dimming/brightening reports (and comparison to posited CO2 forcing would be interesting too) e.g.

    Martin Wild, 2012: Enlightening Global Dimming and Brightening. Bull. Amer. Meteor. Soc., 93, 27–37.


    Fig. 2. [page 29] Changes in surface solar radiation [SSR] observed in regions with good station coverage during three periods. (left column) The 1950s– 1980s show predominant declines (“dimming”), (middle column) the 1980s–2000 indicate partial recoveries (“brightening”) at many locations, except India, and (right column) recent developments after 2000 show mixed tendencies. Numbers denote typical literature estimates for the specified region and period in W m–2 per decade. Based on various sources as referenced in Wild (2009).

    Average USA/Europe/China-Mongolia/Japan/India:

    1950s-1980s: -4.8 W.m-2
    1980s-2000: +2.0 W.m-2
    After 2000: -0.6 W.m-2

    Table 1. [page 33] Magnitudes of linear 2-m temperature trends shown in Fig. 4 during dimming and brightening phases in the NH………Units °C decade–1.

    Dimming phase (1958–85)
    Observed T trend NH −0.002
    Model-calculated T trend NH +0.12

    Brightening phase (1985–2000)
    Observed T trend NH +0.29
    Model-calculated T trend NH +0.19


    The latest updates on solar radiation changes observed since the new millennium show no globally coherent trends anymore (see above and Fig. 2). While brightening persists to some extent
    in Europe and the United States, there are indications for a renewed dimming in China associated with the tremendous emission increases there after 2000, as well as unabated dimming in India (Streets et al. 2009; Wild et al. 2009).

    Cloud/aerosol forcing range 1950s to 2000+:
    -10 W.m-2 to +8 W.m-2. Sfc

    By comparison, the current rate of CO2 forcing is:
    +0.3 Wm-2/decade.TOA

    It is impossible to detect +0.3 CO2 forcing among SSR fluctuations at the surface of -10 to +8. Neither will CO2 forcing of +0.3 have made any difference among SSR after 2000:

    +8 USA
    +3 Europe
    -4 China/Mongolia
    0 Japan
    -10 India

    Average SSR USA/Europe/China-Mongolia/Japan/India (from above):
    1950s-1980s: -4.8 W.m-2
    1980s-2000: +2.0 W.m-2
    After 2000: -0.6 W.m-2″

    3 decades x -4.8 = -14.4 W.m-2 SSR 1950s-1980s
    3 decades x +0.2 = +0.6 W.m-2 CO2 1950s-1980s (roughly)

    2 decades x +2.0 = +4.0 W.m-2 SSR 1980s-2000
    2 decades x +0.3 = +0.6 W.m-2 CO2 1980s-2000 (roughly)

    1 decade x -0.6 = -0.6 W,m-2 SSR after 2000
    1 decade x +0.3 = +0.3 W,m-2 CO2 after 2000 (calculated)

    SSR was obviously the radiative temperature driver 1950-2010 – not CO2.

    # # #

    Having said that, signal analysis of GAST shows a correlation of the oscillatory component with PDO+AMO. Macias et al (2014) and others lump this in to the term “natural variation”.

    It follows then that cloudiness and ocean oscillation are probably in the same phases. Problem is (I may be wrong) the cloudiness data doesn’t extend back long enough to relate to ocean oscillations. I can’t recall a study like this but if there is any I’d like to see them. Maybe a project for John McLean?

  4. Richard C (NZ) on 28/03/2015 at 12:28 pm said:

    ‘First Principles of Meteorology and Air Pollution’ [Book]
    Authors: Lazaridis, Mihalis

    Chapter 2: First Principles of Meteorology [from web search]

    2.6.3 Heating of the Earth’s Surface and Heat Conduction

    Radiation from the sun is the main heat source for the Earth’s surface. The heating of the surfaces and their temperature is dependent on a number of parameters such as:

    The absorbency of a surface. Everybody that receives a quantity of radiation absorbs part of its energy. The percentage of adsorption is dependent on the body’s nature and the radiation.

    # # #

    Climate science would have everyone believe that SWR power (solar received at surface) = DLR power (downwelling from atmospheric air mass to the surface) on a Watts per m^2 to Watts per m^2 basis, and that the heating effect (absorption) on a material e.g. seawater, is exactly the same for SWR and DLR on that basis.

    First Principles of Meteorology disagrees.

    So how do climate scientists Wratt and Renwick (Reisinger excused), qualified in atmospheric physics and sciences respectively i.e. meteorology fundamentals (hopefully), wriggle out of this?

  5. Richard C (NZ) on 28/03/2015 at 1:20 pm said:

    >”Climate science would have everyone believe that SWR power (solar received at surface) = DLR power (downwelling from atmospheric air mass to the surface) on a Watts per m^2 to Watts per m^2 basis, and that the heating effect (absorption) on a material e.g. seawater, is exactly the same for SWR and DLR on that basis.”

    Like this (Earth’s Energy Budget):

    161 W.m-2 incoming solar radiation (SWR/SSR) “adsorbed by surface”
    333 W.m-2 back radiation (DLR) “adsorbed by surface”

    Except what climate science DOES NOT SAY is that the respective adsorption and heating effect, SSR vs DLR is radically different especially for seawater covering the greater part of the earth’s surface.

    First Principles of Meteorology on the other hand, without going into detail, DOES SAY “the percentage of adsorption is dependent on the body’s nature and the radiation” i.e. the heating effect is not the same for SSR and DLR on a W.m-2 to W.m-2 basis.

    Climate science lies by omission, meteorology tells the truth overtly. In which camp are you David Wratt and James Renwick?

  6. Richard C (NZ) on 28/03/2015 at 3:38 pm said:

    Wratt, Reisinger and Renwick (WRR) say nothing whatsoever about climate model failure (graphed below) in their 7 point opinion rebuttal i.e. they avoid the topic like the plague and they haven’t rebutted Carter and Leyland. I keep saying, and John McLean highlights the omissions, it’s what these guys DON’T SAY that matters.

    The closest they venture to that hornets nest (can of worms) is this:

    “So periods of slower atmospheric warming are expected from time to time, followed by periods of faster warming. These short-term wiggles don’t change the long-term picture while greenhouse gas concentrations continue to increase”

    There were only 2 decades of warming, 1980s and 1990s, in the IPCC’s 6 decade anthro attribution period 1951 – 2010. If 18 years of at most minimal warming during the most GHG emissions ever is a “short-term wiggle” then so is the 20 years of greater warming with lessor GHG emissions.

    Elsewhere in the scientific literature the respective phases of the oscillation (the “short-term wiggles”, not the secular trend), warming-cooling-warming-cooling are being attributed to “natural variation”. That just leaves the secular trend for attribution. The 1980s and 1990s warming is NOT the secular trend in temperature, the most recent secular trend is decelerating away from the accelerating CO2 i.e. CO2 cannot be the driver of the secular trend.

    Wratt, Reisinger and Renwick opinion here:

    Carter and Leyland pointed explicitly to the model failure in their ‘Hypothetical global warming: scepticism needed’ opinion’ point 1. and John McLean provides the IPCC corroboration:

    “Of the Intergovernmental Panel on Climate Change’s (IPCC) 114 climate model runs 111 failed to predict this lack of warming [over the last 18 years (see point 1.)]”

    A spectacular failure.

    Carter and Leyland opinion here:

    Meanwhile, this is the John Christy graph of the climate model failure that Republican Senator Jeff Sessions presented to the US Senate on Jan 27, 2015:

    If Wratt, Reisinger and Renwick think the observations are merely a “short-term wiggle” compared to what they seem to be espousing as some sort of CO2-forced model reality then they’re seriously deluded.

    But on the actual model failure as graphed, they’re simply liars by omission.

  7. Richard C (NZ) on 28/03/2015 at 4:10 pm said:

    [Wratt, Reisinger and Renwick] – 7. A substantial contribution to the observed increase in average global surface temperature since the mid-20th century has come from increasing greenhouse gas concentrations. There is no other plausible way to explain the observed changes.

    Again as always, there was only 2 decades of observed increase in average global surface temperature since the mid-20th century. The IPCC AR5 Summary For Policymakers Figure 1 confirms this:

    So, there is no other plausible way than increasing GHG concentrations to explain the observed changes over only the 20 years 1980 – 2000 according the NZs foremost climate scientists?

    I don’t think so. Upthread there’s this comparison (SSR = Surface Solar Radiation):

    2 decades x +2.0 = +4.0 W.m-2 SSR 1980s-2000
    2 decades x +0.3 = +0.6 W.m-2 CO2 1980s-2000

    Apart from the obvious negligibility of CO2 vs the overwhelming solar forcing, the CO2 forcing is in the DLR spectrum 3 – 16+ µm wavelength. SSR is in the 10 nm – 3 µm range. SSR provides surface heating, DLR has minimal surface effect which, if it is to be considered, would be to aid evaporation i.e. a cooling effect.

    Then there’s the cloudiness changes covered by the McLean paper.

    That’s 2 plausible ways, 1 of which blows the expert climate scientists GHG contention to smithereens.

  8. Richard C (NZ) on 29/03/2015 at 12:13 pm said:

    >”John McLean is a PhD candidate, climate researcher, computer scientist and IPCC reviewer and lives in Melbourne.”

    John McLean [McLean (2014]
    Department of Physics, College of Science Technology and Engineering, James Cook University,
    Townsville, Australia

    Has he moved, or does he commute?

  9. Richard Treadgold on 29/03/2015 at 12:15 pm said:

    “Has he moved, or does he commute?”

    I don’t know, but as a PhD candidate he might well be required at the university only occasionally.

  10. Richard C (NZ) on 29/03/2015 at 1:23 pm said:

    OK, just read McLean (2014) word-for-word. Good paper but I don’t think we’ll see it given any air-time among the CO2-is-warming-the-planet science cartel and their camp followers. John obviously doesn’t set out to make friends of them, e.g.

    3.2. The El Nino-Southern Oscillation (ENSO) [see page 6]

    “Trenberth et al. [26] attempts to split the ENSO-temperature relationship into two periods, 1950-1978
    and 1979-1998, and because the change in the relationship after 1987 wasn’t identified concludes that only 0.06˚C of the warming between 1950 and 1998 could be attributed to the ENSO”


    “Foster and Rahmstorf [33] considers only the period since 1979 and therefore largely omitted the period from 1950 to 1987 during which the global average temperature anomaly varied little”


    My initial first-skim criticism was (from upthread) “I think he’s overlooked the important dimming/brightening reports (and comparison to posited CO2 forcing would be interesting too)”

    The dimming/brightening has been covered upthread with examples and I still think John should have made recourse to those reports and studies but I initially missed John’s CO2 vs SSR forcing comparison because it’s not the broad focus of the paper. However it certainly is the focus of the Discussion and Conclusion (see below).

    But I think John has the CO2 part of the comparison wrong. Here’s the two relevant excerpts:

    3.4. Coincidental Variations in Global Average Cloud Cover (see page 8)

    “The reduction in total cloud cover [1984-2009 inclusive)] is significant in the context of the energy budget described by Trenberth et al. [34] , which indicates that cloud reflect 23% of the 341 Wm−2 (i.e. 79 Wm−2) of incoming solar radiation. The reduction in total cloud cover of 6.8% means that 5.4 Wm−2 (6.8% of 79) is no longer being reflected but acts instead as an extra forcing into the atmosphere, some of which will be lost when it adds to the longwave radiation to space. Of course clouds have many other effects on the earth’s radiation budget many of which are not fully understood, but a change of 5.4 Wm−2 is potentially of considerable significance.
    To put this into context, the IPCC Fifth Assessment Report [1], section 8.5.2, states that the total anthropogenic radiative forcing for 2011 relative to 1750 is 2.29 [1.13 to 3.33] Wm−2 for all greenhouse gases and for carbon dioxide alone is 1.68 [1.33 to 2.03] Wm−2. The increase in radiative forcing caused by the reduction in total cloud cover over 10 years is therefore more than double the IPCC’s estimated radiative forcing for all greenhouse gases and more than three times greater than the forcing by carbon dioxide alone. Even the upper limits of the IPCC’s estimates fall well short of the increase in radiative forcing caused by the reduction in total cloud cover.”


    4. Discussion (see page 14)

    (b) Phase II (1988-1997)
    ” The temperature pattern for the period 1988-1997 appears to be generally consistent with the 7% reduction in total cloud cover that occurred across the period 1987 to 1999. Applying that reduction to the influence of clouds in the energy budget described by Trenberth et al. [34] results in an increased average solar forcing at the Earth’s surface of about 5 Wm−2. This increase is more than double the IPCC’s estimated radiative forcing from all anthropogenic emissions of greenhouse gases.”

    Martin Wild (2012) upthread details global and regional dimming/brightening and therefore SSR. SSR is obviously the dominant forcing and John Mclean has this right – no problem with John’s SSR.

    But the CO2 forcing in the periods of 3.4 (1984-2009) and 4. (1988-1997) is MUCH LESS than John’s figures. John has quoted the forcings relative to 1750. The apples-to-apples comparisons for 3.4 and 4. is CO2 forcing relative to 1984 and 1988 respectively, not 1750.

    IPCC CO2 forcing expression dF = 5.35 ln(C/Co)

    Globally averaged marine surface annual mean CO2 data

    1984 343.98
    2009 386.28
    dCO2 = 0.62 W.m-2
    dSSR = 5.4 W.m-2
    5.4/0.62 = 8.7 i.e. SSR forcing is 8.7 times CO2 forcing 1984-2009.

    1988 351.17
    1997 362.92
    dCO2 = 0.18 W.m-2
    dSSR = 5.0 W.m-2
    5/0.18 = 27.8 i.e. SSR forcing is 27.8 times CO2 forcing 1988-1997

    Clearly, SSR forcing is many times greater then CO2 forcing over these 2 critical periods than what John presents.

  11. Richard C (NZ) on 29/03/2015 at 3:20 pm said:

    [McLean] – “One forcing that might have been under-estimated is cloud cover. Variations in total solar irradiance are often discussed but not variations in cloud cover, but cloud cover impedes the flow of radiation, which in general means that it controls the amount of radiation reaching the Earth’s surface during the day, and how much heat is lost during overnight cooling”

    Cloud cover and surface solar radiation (SSR) is a decadal to multi-decadal factor so is relevant to the Mclean study period of 1950 – 2009. SSR is the dominant forcing over this timeframe (CO2 negligible). TSI was at Modern Grand Maximum levels from about 1958 – 2005 which roughly corresponds to the McLean study period i.e. TSI virtually unchanged over that period and no forcing to consider. This timeframe is the oscillatory component of global temperature (“natural variation”, “short-term wiggles”, “60 yr climate cycle” etc) the signal of which can be extracted and isolated leaving the secular trend. SSR (and CO2) have no relationship to the secular trend (that I’ve ever seen).

    But over millennial timeframes e.g. Medieval WP – LIA – Modern WP, TSI is the dominant forcing. SSR is irrelevant (as is CO2). TSI change lagged for planetary thermal inertia (say 30 – 40 years) corresponds to the secular trend of global temperature. Medieval – LIA – Modern is by far the greater climate change than 1950 – 2009 so TSI and a millennial timeframe deserves the most scrutiny IMO. Millennial solar change is the IPCC’s greatest uncertainty but not surprising when they discount the literature covering it, as they do any climate connections.

    Not to downplay McLean (2014), but I’m looking forward to when scientific and media attention moves past the oscillatory component of global temperature and (back) on to the secular trend over millennial timeframes (again, now the the hockey stick has been shredded).

  12. Richard C (NZ) on 31/03/2015 at 8:52 am said:

    >”now the the hockey stick has been shredded”

    Greg Jones on Mann:

    Mann’s endorsement of a pause is about as close to acceptance [5th stage of loss and grief] as possible, the theological equivalent of Richard Dawkins saying, “Okay, so maybe there’s a God.”

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