PNAS climate clowns Ripped by Aussie Professor
PNAS (Proceedings of the National Academy of Sciences) called out over junk climate ‘science’ paper refuse to run detailed rebuttal letter from skeptic.
The publication at issue, ‘Centuries of thermal sea-level rise due to anthropogenic emissions of short-lived greenhouse gases,’ (PNAS January, 2017) is carefully dissected and disproved in a letter to PNAS submitted by Dr Albert Parker, a peer-reviewed expert debunking similar such claims. But because PNAS operates a closed door policy towards climate skeptic experts we are delighted to post Dr Parker’s detailed takedown below.
Dr Parker writes:
Somebody in PNAS wants us to believe somebody knows with perfect accuracy the “global” concentrations of CO2, N2O, CH4 and HC and how they affect the global sea level rise by thermal expansion since the year 1800 to then predict their influence until the year 2800.
Zickfeld, Solomon & Gilford (2017) discuss how mitigation of anthropogenic greenhouse gases (GHG) with short lifetimes of the order of a year to decades impacts on longer-term sea-level-rise (SLR). Based on models, they show that short-lived GHG contribute to sea-level-rise through thermal expansion (TSLR) over much longer time scales than their atmospheric lifetimes. The time window of their study is 1,000 years, 1800-to-2800.
[Ed note: all graphs appear below] Their Fig.1.a (here Fig1.a) should include the uncertainty for the global CO2 concentration inferred from measurements up to present. Satellite measurements of CO2 concentrations such as GOSAT or OCO2 are still far from being routine now, but they show a strongly variable concentration in space (Parker & Ollier, 2015; Parker, 2015). Single point measurements collected over less than 60 years in Mauna Loa and few other even more scattered measurements do not provide an accurate representation of the global CO2 concentration 1800-to-present.
Their Fig.1 should also show the global concentrations of N2O/CH4/HC inferred from actual measurements up to present and include their uncertainties. The global concentrations of N2O/CH4/HC are even less supported by actual measurements than the global concentration of CO2.
Their Fig.1.d (here Fig1.b) should include the uncertainty also for the global TSLR concentration inferred from measurements up to present. With very few tide gauges providing relative SLR results since the 1800s (PSMSL, 2017) and no contemporary measure of the absolute vertical movement of the tide gauge instrument, the estimation of the global TSLR is also imprecise.
Their computed TSLR show a different behavior from the tide gauge signals. The measured relative SLR show pretty much same oscillations about same linear trend influenced by local subsidence or isostasy over the last century, with naïve average only about +0.2 mm/year (Parker, Saad Saleem & Lawson, 2013; Parker, 2015; Parker & Ollier, 2016), examples in Fig.1.c,d,e,f. The computed TSLR is continuously increasing with time since 1800, with acceleration always positive and always increasing with time. In Brest, Fig. 1.c, there are oscillations of sea-levels about a de-trended line during the 1800s (zero velocity, zero acceleration). Then, suddenly, there is a change of slope about the year 1900, with afterwards oscillations of sea-levels about a +1.48 mm/year straight line (positive velocity, but no acceleration). Baltimore, Seattle or Honolulu, Fig.1.d,e,f, have similar pattern of positive velocity, but no acceleration since the early 1900s.
Their model only accounts for the GHG contribution while neglecting other forcings, such as the total solar irradiance, Fig.1.g (LASP, 2017; Coddington, Lean, Pilewskie, Snow & Lindholm, 2016), that at least partially explain the pattern of Fig. 1.c to f based on true measurements.
Their correlation between global concentrations of CO2/N2O/CH4/HC and TSLR therefore suffers of significant uncertainties that are unquantified. Thus, their model is basically not validated and consequently not usable.
References
⦁ K. Zickfeld, S. Solomon & D.M. Gilford (2017), “Centuries of thermal sea-level-rise due to
anthropogenic emissions of short-lived greenhouse gases,” PNAS, vol. 114, no. 4, pp. 657–662.
⦁ A. Parker & C.D. Ollier (2015), “Carbon dioxide flux measurements based on satellite observations differ considerably from the consensus values,” Energy & Environment, Vol. 26, No. 3, pp. 457-463.
⦁ A. Parker (2015), “Discussion of the NASA OCO-2 Satellite Measurements of CO2 Concentrations,” Physics Journal, Vol. 1, Issue 3, pp. 189-193.
⦁ NOAA (2017), “Full Mauna Loa CO2 record,” https://www.esrl.noaa.gov/gmd/ccgg/trends/full.html, accessed February 4, 2017.
⦁ PSMSL (2017), “Obtaining Tide Gauge Data,”
http://www.psmsl.org/data/obtaining/, accessed February 4, 2017.
⦁ A. Parker, M. Saad Saleem & M. Lawson (2013), “Sea-Level Trend Analysis for Coastal Management,” Ocean & Coastal Management, Vol. 73, pp. 63–81.
⦁ A. Parker (2014), “PRESENT CONTRIBUTIONS TO SEA-LEVEL-RISE BY THERMAL EXPANSION AND ICE MELTING AND IMPLICATION ON COASTAL MANAGEMENT,” Ocean and Coastal Management, Vol.98, pp. 202-211.
⦁ A. Parker & C.D. Ollier (2016), “COASTAL PLANNING SHOULD BE BASED ON PROVEN SEA LEVEL DATA,” Ocean and Coastal Management, Vol. 124, pp. 1-9.
⦁ LASP (2017), “Reconstructed Total Solar Irradiance,”
http://lasp.colorado.edu/home/sorce/files/2011/09/TIM_TSI_Reconstruction-1.png
⦁ Coddington, O., J. L. Lean, P. Pilewskie, M. Snow & D. Lindholm (2016), “A solar irradiance climate data record.” Bulletin of the American Meteorological Society, Vol.97, no. 7, pp. 1265-128
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