Climate models play a central role in the attribution of global warming or climate change to human causes. The standard argument takes the following form: “We can get the model to do X, using human causes, but not without them, so human causes must be the cause of X.” A little digging reveals that this is actually a circular argument, because the models are set up in such a way that human causes are the only way to get change.
The finding is that humans are the cause of global warming and climate change is actually the assumption going in. This is circular reasoning personified, namely conclude what you first assume.
This circularity can be clearly seen in what many consider the most authoritative scientific report on climate change going, although it is actually just the most popular alarmist report. We are talking about the Summary for Policymakers (SPM), of the latest assessment report (AR5), of the heavily politicized UN Intergovernmental Panel on Climate Change (IPCC). Their 29 page AR5 SPM is available here.
Reliability of future global warming projections depends on how well climate models reproduce the observed climate change over the twentieth century. In this regard, deviations of the model-simulated climate change from observations, such as a recent “pause” in global warming, have received considerable attention. Such decadal mismatches between model-simulated and observed climate trends are common throughout the twentieth century, and their causes are still poorly understood. Here we show that the discrepancies between the observed and simulated climate variability on decadal and longer timescale have a coherent structure suggestive of a pronounced Global Multidecadal Oscillation. Surface temperature anomalies associated with this variability originate in the North Atlantic and spread out to the Pacific and Southern oceans and Antarctica, with Arctic following suit in about 25–35 years. While climate models exhibit various levels of decadal climate variability and some regional similarities to observations, none of the model simulations considered match the observed signal in terms of its magnitude, spatial patterns and their sequential time development. These results highlight a substantial degree of uncertainty in our interpretation of the observed climate change using current generation of climate models.
After years of trying to suppress their release, and finally being ordered to be released by a judge, they are now public, and we have them here. This will remain as a “top post” for a day, new stories will be below this one.
There’s quite a treasure trove, but also some duplications from previous releases.
Comme déjà mentionné dans un article précédent publié sur SCE, la variation de la couverture nuageuse a probablement un effet majeur sur la température moyenne globale de la basse atmosphère. Si l’on veut prédire le climat du futur comme le prétend le GIEC il faut savoir modéliser la formation des nuages. Que nous dit le dernier rapport scientifique (AR5) du GIEC à ce sujet? Le but du présent article est simplement de vous présenter quelques phrases tirées de ce rapport. La science est-elle dite?
1. Le chapitre 7 du rapport AR5 publié par le GIEC en 2013
Le chapitre 7 du rapport AR5 du GIEC[1] fait 60 pages et est consacré aux nuages et aux aérosols (le rapport AR5 complet fait au total 1535 pages). Ce chapitre 7 comporte 22 pages de références et cite plus de 1100 articles scientifiques publiés dans des revues aussi prestigieuses que Science, Nature ou PNAS. Le chapitre 7 a été écrit sous la direction de Olivier Boucher (France) et David Randall (USA), deux spécialistes du domaine. Nous n’allons pas ici remettre en question la validité de ce chapitre. Nous allons simplement vous présenter quelques phrases tirées du rapport. Comme le rapport est écrit en anglais nous vous proposerons ci-dessous une “traduction maison” des phrases qui nous paraissent les plus importantes, assorties parfois de quelques explications pour bien les comprendre. Les lettres entre crochets ([A] à [P]) renvoient simplement au texte original en anglais, donné en Annexe du présent article.
Science differs from religion because theoretical claims have to be verified with observations. If model results can predict measurements in advance (which is quite different than explaining them afterwards!) then you can say the model validated and then apply it in practice. But if that is not the case, then you cannot sell the model as truth and using it in practice is irresponsible.
Far more complicated than simple, linear CO2 relationship
The current climate model (‘IPCC model’) systematically yields highly overstated predictions compared to measurements and can therefore not be used to form climate policy – especially if that policy results in extremely high costs and destabilises vital parts of the energy infrastructure.
We are not just saying that. Already some of the most renowned scientists have preceded us (e.g. Freeman Dyson, Frederic Seitz, Robert Jastrow, William Nierenberg), including Nobel Prize winners (e.g. Ivar Giaever and Robert Laughlin). They also argue that the earth’s climate is far too complicated to be explained by a simple one-dimensional CO2 relationship.
by Kevin Murphy in Judith Curry, January 28, 2019 in ClimateEtc.
A response to: “Is RCP8.5 an impossible scenario?”. This post demonstrates that RCP8.5 is so highly improbable that it should be dismissed from consideration, and thereby draws into question the validity of RCP8.5-based assertions such as those made in the Fourth National Climate Assessment from the U.S. Global Change Research Program.
Analyses of future climate change since the IPCC’s 5th Assessment Report (AR5) have been based on representative concentration pathways (RCPs) that detail how a range of future climate forcings might evolve.
Several years ago, a set of RCPs were requested by the climate modeling research community to span the range of net forcing from 2.6 W/m2 to 8.5 W/m2 (in year 2100 relative to 1750) so that physics within the models could be fully exercised. Four of them were developed and designated as RCP2.6, RCP4.5, RCP6.0 and RCP8.5. They have been used in ongoing research and as the basis for impact analyses and future climate projections.
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Figure 2. History and forecasts of CO2 concentration. RCP8.5 is defined by 936 ppm in 2100.
London, 20 December: One of Europe’s most eminent climate scientists has documented the main scientific reasons why the recent UN climate summit failed to welcome the IPCC’s report on global warming of 1.5°C.
In a paper published today by the Global Warming Policy Foundation Professor Ray Bates of University College Dublin explains the main reasons for the significant controversy about the latest IPCC report within the international community.
The IPCC’s Special Report on a Global Warming of 1.5°C (SR1.5) was released by the Intergovernmental Panel on Climate Change (IPCC) in advance of the recent COP24 meeting in Katowice, Poland, but was not adopted by the meeting due to objections by a number of governments.
Professor Bates examines some key aspects of the SR1.5 report. He assesses if the IPCC report exhibits a level of scientific rigour commensurate with the scale of its extremely costly and highly disruptive recommendation that carbon emissions be reduced to zero by mid-century.
The paper concludes that such a level of scientific rigour is not present in the report. Specifically, SR1.5 is deficient in scientific rigour in the following respects:
Climate change: How could artificial photosynthesis contribute to limiting global warming?
Scientists calculate areas needed for forestation and artificial photosynthesis.
After several years during which global emissions at least stagnated, they rose again somewhat in 2017 and 2018. Germany has also clearly missed its climate targets. In order to keep global warming below 2 degrees Celsius, only about 1100 gigatonnes of CO2 may be released into the atmosphere by 2050[1]. And In order to limit global warming to 1.5 degrees, only just under 400 gigatonnes of CO2 may be emitted worldwide. By 2050, emissions will have to fall to zero even. Currently, however, 42 gigatonnes of CO2 are added every year.
Almost all the various scenarios require “negative emissions”
In late 2018 the Intergovernmental Panel on Climate Change (IPCC) released a report on the impacts associated with global warming of 1.5°C (2.7°F) above preindustrial levels (as of 2019 we are at about 1.0°C above pre-industrial levels) as well as the technical feasibility of limiting global warming to such a level. The media coverage of the report immediately produced a meme that continues to persist. The meme is some kind of variation of the following:
The IPCC concluded that we have until 2030 (or 12 years) to avoid catastrophic global warming
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However, these headlines are essentially purveying a myth. I think it is necessary to push back against this meme for two main reasons:
1) It is false.
2) I believe that spreading this messaging will ultimately undermine the credibility of the IPCC and climate science more generally.
Taking these two points in turn:
1) The IPCC did not conclude that society has until 2030 to avoid catastrophic global warming.
The prolonged el Niño of 2016-2017, not followed by a la Niña, has put paid to the great Pause of 18 years 9 months in global warming that gave us all such entertainment while it lasted. However, as this annual review of global temperature change will show, the credibility gap between predicted and observed warming remains wide, even after some increasingly desperate and more or less openly prejudiced ever-upward revisions of recent temperatures and ever-downward depressions in the temperatures of the early 20th century in most datasets with the effect of increasing the apparent rate of global warming. For the Pause continues to exert its influence by keeping down the long-run rate of global warming.
Climate models postulate that increasing CO2 concentrations will intensify the Earth’s water cycle. This intensification is believed to eventually result in dangerous (3°C and up) global warming. Observational evidence has thus far falsified these IPCC-endorsed claims.
Three decades after a top climate scientist warned Congress of the dangers of global warming, greenhouse gas emissions keep rising and so do global temperatures.
Thirty years ago, a NASA scientist, James Hansen, told lawmakers at a Senate hearing that “global warming is now large enough that we can ascribe with a high degree of confidence a cause-and-effect relationship with the greenhouse effect.” He added that there “is only 1 percent chance of accidental warming of this magnitude.”
By that, he meant that humans were responsible.
His testimony made headlines around the United States and the world. But in the time since, greenhouse gas emissions, the global temperature average and cost of climate-related heat, wildfires, droughts, flooding and hurricanes have continued to rise.
When you put the claims of the Intergovernmental Panel on Climate Change (IPCC) in perspective, you get a very different picture that defies logic. I decided to do this because of their recent hysterical claims in Special Report 15 (SR-15) designed to frighten and bully the world into completely unnecessary and enormously expensive environmental and energy policies. Charles Steele summarized their claims and proposed policies in his article, “Climate Doom Ahead? Think Twice,”
The significance of this new GWPF report by Prof Ray Bates of the Meteorology and Climate Centre at University College Dublin cannot really be overstated:
London, 20 December: One of Europe’s most eminent climate scientists has documented the main scientific reasons why the recent UN climate summit failed to welcome the IPCC’s report on global warming of 1.5°C.
In a paper published today by the Global Warming Policy Foundation Professor Ray Bates of University College Dublin explains the main reasons for the significant controversy about the latest IPCC report within the international community.
The IPCC’s Special Report on a Global Warming of 1.5°C (SR1.5) was released by the Intergovernmental Panel on Climate Change (IPCC) in advance of the recent COP24 meeting in Katowice, Poland, but was not adopted by the meeting due to objections by a number of governments.
Almost immediately after it was introduced to the public, the lead author of Marcott et al. (2013) squelched the narrative that said the hockey-stick-shaped reconstruction he and his colleagues produced is a robust representation of modern global-scale temperature changes.
In an interview with Marcott published by RealClimate.org, it was acknowledged that the “uptick” does not represent a global-scale reconstruction, as it is based on only a few proxy records and lacks statistical significance.
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Despite this admitted lack of supporting evidence for the 20th century’s “uptick”, the Marcott et al. (2013) “hockey stick”-shaped graph has nonetheless been unskeptically cited by other authors nearly 700 times.
Patricia Adams is an economist and the executive director of Probe International, a Toronto based NGO that has been involved in the Chinese environmental movement since its beginnings in the mid-1980s.
She is confirming much of what I have said in recent years. The only thing I would take issue with his her description of there being a U-Turn. In my view, China never had the slightest intention of being serious about cutting emissions.
by J.C. Maurin, 2 décembre 2018 in ScienceClimatEnergie
Au XVIe siècle, dans une ultime tentative pour sauver le système de Ptolémée, on se résigna enfin à admettre la rotation des planètes autour du Soleil mais on conserva le dogme de la position centrale de la Terre par rapport au Soleil. Le dernier pas vers l’héliocentrisme dut finalement être franchi, à regret. Au XXIesiècle, Le GIEC adapte discrètement son Almageste : on lit dans la version de novembre 2018 du Résumé à l’intention des décideurs dès la première page, 1er encadré de l’introduction → “L’augmentation mondiale de la concentration en dioxyde de carbone est essentiellement due à l’utilisation des combustibles fossiles et aux changements d’affectation des terres”. Fin de cette première page → « La source principale de l’augmentation de la concentration du dioxyde de carbone dans l’atmosphère depuis l’époque préindustrielle provient de l’utilisation des combustibles fossiles ». La certitude absolue, naguère affichée, d’une origine 100% anthropique dans la hausse du CO2atmosphérique disparaît donc. Un modèle mixte est désormais implicitement admis. A cinq siècles de distance, le dernier pas reste toujours difficile à franchir. Le présent article aide à trouver le chemin de Damas.
Figure 1. Rappels des observations (1/4) et corrélations (2/4)
D’abord cette info surprenante. Une étude récente sur le réchauffement des océans a dû être modifiée après publication dans Nature. L’étude, très alarmiste, avait pourtant été révisée puis validée par un comité de lecture et publiée dans la plus prestigieuse revue scientifique au monde. Or la méthodologie et les conclusions de cette recherche étaient erronées.
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La faille a été découverte par Nic Lewis, un chercheur climato-critique très populaire en Grande-Bretagne. Il affirme, et les faits lui donnent raison: « Je suis légèrement surpris que ni les pairs examinateurs ni le rédacteur en chef n’aient repéré ce qui me semblait être une alarme rouge à la page 1. »
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 leδ13C de -8.3 ‰. Il existe une modulation annuelle de ce taux, très marquée dans l’hémisphère Nord.
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 ?
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).
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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.
The Intergovernmental Panel on Climate Change (IPCC) published a special report (hereafter called SR15) on the impacts of global warming of 1.5 °C above pre-industrial levels on October 8, 2018. The report says the cost of mitigating CO2 emissions in 2030 to prevent temperatures from exceeding 1.5 °C above pre-industrial levels is about 880 US$2010 per tonne of CO2 ($/tCO2). The benefit of doing so, according to the report, is 15 $/tCO2. Using a climate sensitivity based on observations including effects of natural climate change, urban warming and the best available economic model, the mitigation proposal will prevent a benefit of 8.2 $/t CO2, for a total loss of 888 $/tCO2 mitigated. In other words, each $1000 spent on mitigation of CO2 emissions will cause another loss $9.20.
The SR15, presents various emissions pathways to limit the projected rise of temperatures from pre- industrial times, estimated to be the temperature average from 1850 to 1900, to the year 2100, and to limit the temperature rise to 2.0 °C by 2100. According to the IPCC, temperatures have increased by about 1.0 °C from pre-industrial times to 2017. Therefore, the emissions pathways to limit warming allows only 0.5 °C temperature rise from 2017, assuming there is no natural caused climate change.
