Archives par mot-clé : Model(s)

Evolutions récentes du CO2 atmosphérique (3/4)

by J.C. Maurin, 12 novembre 2018 in ScienceClimatEnergie


L’IPCC (GIEC en français) fut créé en 1988 par l’UNEP (United Nations Environment Programme) et le WMO (World Meteorological Organization). Dans les principes régissant les travaux du GIEC (1) on lit : Le GIEC a pour mission d’évaluer … les risques liés au changement climatique d’origine humaine.  Le GIEC respecte son propre principe fondateur : il attribue l’intégralité de la hausse du taux de CO2 depuis 1958 à une cause anthropique. Nous examinerons ici le modèle anthropique du GIEC et nous le confronterons aux mesures contemporaines, puis à un modèle mixte. Cet article fait suite aux deux précédents publiés sur le site SCE au cours des mois de septembre (1/4) et octobre 2018 (2/4).

C.   Modèle anthropique GIEC

C.1   Les contraintes des modèles (Fig. 1)

Le paragraphe A (article 1/4) a montré qu’en 1980 le taux de CO2 atmosphérique était de 338 ppm et le  δ13C de -7.6 ‰. En  2010 le taux de CO2  atmosphérique était de 388 ppm et le δ13C de -8.3 ‰. Il existe une modulation annuelle de ce taux, très marquée dans l’hémisphère Nord.

 

Interview exclusive: Henri Masson, Université d’Anvers, déclare les modèles du GIEC « aberration statistique »

by Henri Masson, 10 mars 2012, in Contrepoints


Des modèles, cela fait 40 ans que j’en fais », précise d’emblée Henri Masson. Ingénieur chimiste de formation (Université Libre de Bruxelles), docteur en sciences appliquées, professeur émérite à l’Université d’Anvers, expert globe-trotter (notamment pour la Banque Mondiale et l’ONU), l’homme est, de surcroît, doté d’un sérieux sens de la vulgarisation. Lorsque Contrepoints lui propose d’analyser les modèles prédictifs du GIEC, le Belge est catégorique : « Si mes étudiants me présentaient de tels modèles, je n’hésiterais pas à les recaler ! »

Contrepoints : Quelle confiance peut-on accorder aux modèles du GIEC, qui prévoient, parmi d’autres choses, un réchauffement planétaire dû aux émissions humaines de CO2 ?

Evolutions récentes du CO2 atmosphérique (3/4)

by J.C. Maurin, 12 novembre 2018 in  ScienceClimatEnergie


L’IPCC (GIEC en français) fut créé en 1988 par l’UNEP (United Nations Environment Programme) et le WMO (World Meteorological Organization). Dans les principes régissant les travaux du GIEC (1) on lit : Le GIEC a pour mission d’évaluer … les risques liés au changement climatique d’origine humaine.  Le GIEC respecte son propre principe fondateur : il attribue l’intégralité de la hausse du taux de CO2 depuis 1958 à une cause anthropique. Nous examinerons ici le modèle anthropique du GIEC et nous le confronterons aux mesures contemporaines, puis à un modèle mixte. Cet article fait suite aux deux précédents publiés sur le site SCE au cours des mois de septembre (1/4) et octobre 2018 (2/4).

C.4.  Conclusions

  • Un modèle qui décrit un monde fixe, en équilibre, un modèle où l’homme est central, un modèle qui parvient à reproduire certaines observations mais pas toutes, un modèle unanimement soutenu par les autorités politiques ou morales, enfin un modèle qui pose a priori un principe intangible… est le type même de modèle qui fut développé  par Ptolémée (6) pour le système solaire. Ce modèle fut jadis l’objet d’un consensus  à  > 97%.

  • L’atmosphère actuelle comporte environ 20 ppm de CO2 anthropique correspondant à 20/400 soit 5% du CO2 atmosphérique. En un siècle les hommes ont donc modifié la composition de l’atmosphère de 20 ppm soit 0,002% : sur ce sujet également, il semble que nous ne soyons pas au centre du monde.

  • Les évolutions récentes du CO2 atmosphérique ne peuvent pas avoir une cause uniquement anthropique: les observations du δ13C l’interdisent. Les causes sont anthropiques et naturelles. Le modèle purement anthropique du GIEC est donc à rejeter.

At IPCC talks Trump Administration emphasizes scientific “uncertainty” and “value of fossil fuels”… MAGA!

by David Middleton, October 4, 2018 in WUWT


95% of the model runs predicted more warming than the RSS data since 1988… And this is the Mears-ized RSS data, the one in which the measurements were influenced to obtain key information (erase the pause and more closely match the surface data).

Their “small discrepancy” would be abject failure in the oil & gas industry.

The observed warming has been less than that expected in a strong mitigation scenario (RCP4.5).

Output of 38 RCP4.5 models vs observations.   The graph is originally from Carbon Brief.  I updated it with HadCRUT4, shifted to 1970-2000 baseline, to demonstrate the post-El Niño divergence.

The ‘Trick’ of Anomalous Temperature Anomalies

by Kip Hansen, September 25, 2018 in WUWT


It seems that every time  we turn around, we are presented with a new Science Fact that such-and-so metric — Sea Level Rise, Global Average Surface Temperature, Ocean Heat Content, Polar Bear populations, Puffin populations — has changed dramatically — “It’s unprecedented!” — and these statements are often backed by a graph illustrating the sharp rise (or, in other cases, sharp fall) as the anomaly of the metric from some baseline.  In most cases, the anomaly is actually very small and the change is magnified by cranking up the y-axis to make this very small change appear to be a steep rise (or fall).

A Test of the Tropical 200- to 300-hPaWarming Rate in Climate Models

by R. McKitrick and J. Christy, July 6, 2018 in AGU100


Abstract
Overall climate sensitivity to CO2
doubling in a general circulation model results from a complex
system of parameterizations in combination with the underlying model structure. We refer to this as the modelsmajor hypothesis, and we assume it to be testable. We explain four criteria that a valid test should meet: measurability, specificity, independence, and uniqueness. We argue that temperature change in the
tropical 200- to 300-hPa layer meets these criteria. Comparing modeled to observed trends over the past
60 years using a persistence-robust variance estimator shows that all models warm more rapidly than
observations and in the majority of individual cases the discrepancy is statistically significant. We argue that
this provides informative evidence against the major hypothesis in most current climate models.

Weather and Climate in the Real World

by Tim Ball, August 18, 2018 in WUWT


All the trillions of dollars spent on AGW have not improved forecasting one bit. Instead, it diverted money that could have helped those large, primary sectors of society and economy that need better and more appropriate information. It is time to close all government weather offices or at least reduce their function to data collection determined by the end users.

Why does climate sensitivity increase over time in models? A look at two possibilities

by A. Zaragoza Comendador, August 16, 2018 in WUWT


Note: if the terms used in this article seem confusing, check out the previous one.

Introduction

It’s well known that climate models show increasing sensitivity over time: for a given forcing, the true long-term temperature increase (ECS) is higher than what you’d estimate if you simply extrapolated from the past (ECS_hist). In other words, the ECS-to-ECS_hist ratio is above 1. This article tries to work out why climate models behave like that; that is to say, the variable I’m trying to explain is the ECS-to-ECS_hist ratio.

Now, there’s probably too many hyphens and underscores in the text. So it will be more readable if I clarify that, every time I talk simply about ‘correlation’, I mean the correlation of thing X with the ECS-to-ECS_hist ratio. If other kind of correlation is mentioned, I’ll say so explicitly.

The Major Change in the Global Warming Groupthink Between 1990 and 1995

byTim Ball, August 12, 2018 in WUWT


Somebody said economists try to predict the tide by measuring one wave. This puts them in the same league as climate scientists trying to predict the climate by measuring one variable, CO2. It is no surprise that an amalgam of the two, climate and economics, produces even worse results, but that is what happened early in the anthropogenic global warming (AGW) deception.

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A Global Warming Hiatus in Northeast China

by Sun X. et al., 2018 in CO2Science


Paper Reviewed
Sun, X., Ren, G., Ren, Y., Fang, Y., Liu, Y., Xue, X. and Zhang, P. 2018. A remarkable climate warming hiatus over northeast China since 1998. Theoretical and Applied Climatology 133: 579-594.

A prominent feature of all climate model projections is their prediction that temperatures should be rising in response to ever-increasing concentrations of greenhouse gases. However, for the past two decades global surface air temperatures have not warmed to the degree predicted by the models, which lack of warming has been a conundrum to the climate alarmist movement.

108 Graphs From 89 New Papers Invalidate Claims Of Unprecedented Global-Scale Modern Warmth

by K. Richard, August 2, 2018 in NoTrickZone


During 2017, there were 150 graphs from 122 scientific papers published in peer-reviewed journals indicating modern temperatures are not unprecedented, unusual, or hockey-stick-shaped — nor do they fall outside the range of natural variability.  We are a little over halfway through 2018 and already  108 graphs from 89 scientific papers undermine claims that modern era warming is climatically unusual.

For the sake of brevity, just 13 (15%) of the 89 new papers are displayed below.

The rest of the non-hockey-stick scientific papers and graphs published thus far in 2018 can be viewed by clicking the link below.

German Scientists: Chris Folland’s Findings On Climate Models “Good For a Loud Laugh”…”Pulling Tricks Like Troopers”

by Dr S. Lüning and Prof. F. Vahrenholt, July 25, 2018 in NoTricksZone


The temperature of the last 100 years was also the topic of a new publication by Folland et al. 2018. The authors are very much at home in the camp of the IPCC and had to admit that there have been phases of cooling, stagnating or even slow warming: 1896 – 1910, 1941 – 1975, and 1998 – 2013.

Climate models struggle with this because CO2 is climbing steadily. So why does climate warming stall under these conditions? Folland and his colleagues examined the models and are convinced that despite the small problems, the models function perfectly well and thus no other climate factors need to be accounted for.

In 1940s it was a bit too warm and the models were unable to reproduce this. Given, the authors say. Greenhouse gases have been responsible for almost all the warming of the last 125 years.

Now isn’t it a bit odd that the authors made absolutely no mention of the ocean cycles in the abstract? As our regular readers know, the ocean cycles run surprisingly synchronous with the fluctuations in global temperatures, i.e. the key factors here are the AMO and PDO.

PDO ocean cycle and its fluctuations in the global temperature development. Source: Book ‘Die kalte Sonne‘.

Global Temperature Rise Some 75% Lower Than Models Projected!

by P. Gosselin, July 18, 2018 in NoTricksZone


No matter how hard climate-catastrophe obsessed alarmists attempt to beat out a little doom from the data, their results still fall far way short of their projections. Moreover, the modest warming the planet has seen over the recent decades is tied more to natural cycles.

Chart: P Gosselin, using WoodForTrees data.

Ross McKitrick: All those warming-climate predictions suddenly have a big, new problem

by Ross McKitrick, June 20, 2018 in FinancialPost


One of the most important numbers in the world goes by the catchy title of Equilibrium Climate Sensitivity, or ECS. It is a measure of how much the climate responds to greenhouse gases. More formally, it is defined as the increase, in degrees Celsius, of average temperatures around the world, after doubling the amount of carbon dioxide in the atmosphere and allowing the atmosphere and the oceans to adjust fully to the change. The reason it’s important is that it is the ultimate justification for governmental policies to fight climate change.

The United Nations Intergovernmental Panel on Climate Change (IPCC) says ECS is likely between 1.5 and 4.5 degrees Celsius, but it can’t be more precise than that. Which is too bad, because an enormous amount of public policy depends on its value. People who study the impacts of global warming have found that if ECS is low — say, less than two — then the impacts of global warming on the economy will be mostly small and, in many places, mildly beneficial.

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100% Of Climate Models Prove that 97% of Climate Scientists Were Wrong!

by Eric Holthaus, May 2018 , in Climatism


SEPTEMBER 2017

Dr. Christy was 100% correct …

A landmark paper by warmist scientists in Nature Geoscience now concedes the world has indeed not warmed as predicted, thanks to a slowdown in the first 15 years of this century. One of its authors, Michael Grubb, professor of international energy and climate change at University College London, admits his past predictions of runaway warming were too alarmist.

When the facts change, I change my mind. We are in a better place than I thought.”

ANOTHER author, Myles Allen, professor of geosystem science at Oxford, confessed that too many of the mathematical models used by climate scientists to predict future warming “were on the hot side” — meaning they exaggerated.

We haven’t seen that rapid acceleration in warming after 2000 that we see in the models.” 

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