Archives par mot-clé : IPCC

Flawed Models: New Studies Find Plants Take Up “More Than Twice As Much” CO2 Than Expected

by Fritz Vahrenholt, July 7, 2020 in NoTricksZone

First, the global mean temperature of satellite based measurements was surprisingly much higher in May 2020 than in April. In contrast, the global temperatures of the series of measurements on land and sea decreased. The difference can be explained by the fact that under warm El-Nino conditions the satellite measurements lag about 2-3 months behind the earth-based measurements.

From November 2019 to March 2020 a moderate El-Nino was observed, which has now been replaced by neutral conditions in the Pacific. Therefore, it is to be expected that also the satellite based measurements, which we use at this point, will show a decrease in temperatures within 2-3 months.

The average temperature increase since 1981 remained unchanged at 0.14 degrees Celsius per decade. The sunspot number of 0.2 corresponded to the expectations of the solar minimum.

The earth is greening

Hot Summer Epic Fail: New Climate Models Exaggerate Midwest Warming by 6X

by Dr Roy Spencer, July 3, 2020 in GlobalWarming

For the last 10 years I have consulted for grain growing interests, providing information about past and potential future trends in growing season weather that might impact crop yields. Their primary interest is the U.S. corn belt, particularly the 12 Midwest states (Iowa, Illinois, Indiana, Ohio, Kansas, Nebraska, Missouri, Oklahoma, the Dakotas, Minnesota, and Michigan) which produce most of the U.S. corn and soybean crop.

Contrary to popular perception, the U.S. Midwest has seen little long-term summer warming. For precipitation, the slight drying predicted by climate models in response to human greenhouse gas emissions has not occurred; if anything, precipitation has increased. Corn yield trends continue on a technologically-driven upward trajectory, totally obscuring any potential negative impact of “climate change”.

What Period of Time Should We Examine to Test Global Warming Claims?

Based upon the observations, “global warming” did not really begin until the late 1970s. Prior to that time, anthropogenic greenhouse gas emissions had not yet increased by much at all, and natural climate variability dominated the observational record (and some say it still does).

Furthermore, uncertainties regarding the cooling effects of sulfate aerosol pollution make any model predictions before the 1970s-80s suspect since modelers simply adjusted the aerosol cooling effect in their models to match the temperature observations, which showed little if any warming before that time which could be reasonably attributed to greenhouse gas emissions.

This is why I am emphasizing the last 50 years (1970-2019)…this is the period during which we should have seen the strongest warming, and as greenhouse gas emissions continue to increase, it is the period of most interest to help determine just how much faith we should put into model predictions for changes in national energy policies. In other words, quantitative testing of greenhouse warming theory should be during a period when the signal of that warming is expected to be the greatest.

50 Years of Predictions vs. Observations

Now that the new CMIP6 climate model experiment data are becoming available, we can begin to get some idea of how those models are shaping up against observations and the previous (CMIP5) model predictions. The following analysis includes the available model out put at the KNMI Climate Explorer website. The temperature observations come from the statewide data at NOAA’s Climate at a Glance website.

For the Midwest U.S. in the summer (June-July-August) we see that there has been almost no statistically significant warming in the last 50 years, whereas the CMIP6 models appear to be producing even more warming than the CMIP5 models did.

IPCC and Sceptics Agree: Climate Change Is Not Causing Extreme Weather

by H.S. Sterling Burnett, June 25, 2020 in GWPF

A new Global Warming Policy Foundation report from retired Oxford physicist Ralph Alexander supports the Intergovernmental Panel on Climate Change’s conclusion there is limited scientific evidence linking human caused climate change to increases in extreme weather.

Alexander’s conclusions are also confirmed by recent documents produced by Heartland Senior Fellow Anthony Watts on the website “Climate at a Glance.”

Alexander’s paper begins by remarking, “[t]he purported link between extreme weather and global warming has captured the public imagination and attention of the mainstream media far more than any of the other claims made by the narrative of human-caused climate change.”

CMIP6 Climate Models Show 50% More Warming Than Observations Since 1979

by Roy W. Spencer, June 26, 2020 in ClimateChangeDispatch

Those who defend climate model predictions often produce plots of observed surface temperature compared to the models which show very good agreement.

Setting aside the debate over the continuing adjustments to the surface temperature record which produce ever-increasing warming trends, let’s look at how the most recent (CMIP6) models are doing compared to the latest version of the observations (however good those are).

First, I’d like to explain how some authors get such good agreement between the models and observations. Here are the two “techniques” they use that most annoy me.

  1. They look at long periods of time, say the last 100+ years. This improves the apparent agreement because most of that period was before there was substantial forcing of the climate system by increasing CO2.
  2. They plot anomalies about a common reference period but do not show trend lines. Or, if they show trend lines, they do not start them at the same point at the beginning of the record. When you do this, the discrepancy between models and observations is split in half, with the discrepancy in the latter half of the record having the opposite sign of the discrepancy in the early part of the record. They say, “See? The observed temperatures in the last few decades nearly match the models!”

In the following plot (which will be included in a report I am doing for the Global Warming Policy Foundation) I avoid both of those problems.

During the period of strongest greenhouse gas forcing (since 1979), the latest CMIP6 models reveal 50% more net surface warming from 1979 up to April 2020 (+1.08 deg. C) than do the observations (+0.72 deg. C).


Continuer la lecture de CMIP6 Climate Models Show 50% More Warming Than Observations Since 1979

Weather Extremes? Are they caused by global warming?

by Ralph Alexander, June 4, 2020 in CO2Colation

Critical Review Confirms IPCC Assessment On Extreme Weather: “No sign that extreme weather events are getting worse”

The paper, by physicist Dr Ralph Alexander, looks at trends in hot and cold weather extremes, floods and droughts, hurricanes and wildfires and finds only a minor increase in cold weather extremes.

According to Dr Alexander, weather extremes is one area where the IPCC has been reasonably empirical and scientific in recent years.

As he explains:

The IPCC stands out, among those who believe that global warming is primarily due to human activity, as a voice of restraint on the issue of extreme weather. My review is in broad agreement with their position: there is little sign things are getting worse.”

In particular, Dr Alexander points to the underreported global reductions in floods, wildfires and hurricanes, but he cautions that many of the changes are likely to be cyclical.

The key driver for many weather extremes is natural ocean cycles like El Nino and the Atlantic Multidecadal Oscillation. Eventually these cycles will turn, and we should be ready. But we shouldn’t be under any illusion that we can prevent extreme weather by changing our lifestyles”.

Weather Extremes: Are They Caused By Global Warming? (pdf)


by Cap Allon, May 27, 2020 in Electroverse

INTERGOVERNMENTAL PANEL ON CLIMATE CHANGE IPCC) THREE PILLARS OF MAN-MADE GLOBAL WARMING: COLLAPSED — by Dr Roger Higgs (DPhil Oxford, geology, 1982-86), Geoclastica LtdTechnical Note 2020-7, 25th May 2020, amended 26-5-2020 on ResearchGate.

The IPCC says ongoing warming is due to man’s CO2 emissions, hence ‘Anthropogenic Global Warming’ (AGW). However, the 3 pillars on which they base this claim are unscientific and quickly disproved.


Manufacturing consensus: the early history of the IPCC

by J. Curry, January 3, 2018 in ClimateEtc.

Short summary: scientists sought political relevance and allowed policy makers to put a big thumb on the scale of the scientific assessment of the attribution of climate change.

Bernie Lewin has written an important new book:

SEARCHING FOR THE CATASTROPHE SIGNAL:The Origins of The Intergovernmental Panel on Climate Change

The importance of this book is reflected in its acknowledgements, in context of assistance and contributions from early leaders and participants in the IPCC:

This book would not have been possible without the documents obtained via Mike MacCracken and John Zillman. Their abiding interest in a true and accurate presentation of the facts prevented my research from being led astray. Many of those who participated in the events here described gave generously of their time in responding to my enquiries, they include Ben Santer, Tim Barnett, Tom Wigley, John Houghton, Fred Singer, John Mitchell, Pat Michaels . . . and many more.

You may recall a previous Climate Etc. post Consensus by Exhaustion, on Lewin’s 5 part series on Madrid 1995: The last day of climate science.

Read the whole book, it is well worth reading.  The focus of my summary of the book is on Chapters 8-16 in context of the theme of ‘detection and attribution’, ‘policy cart in front of the scientific horse’ and ‘manufacturing consensus’. Annotated excerpts from the book are provided below.


by Cap Allon, April, 2020 in Electroverse

Despite decades of doom-and-gloom prophecies, Greenland’s Ice Sheet is currently GAINING monster amounts of “mass” — 27 gigatons over the past 5 days alone (April 14 – 18, 2020).

Crucial to the survival of a glacier is its surface mass balance (SMB)–the difference between accumulation and ablation (sublimation and melting). Changes in mass balance control a glacier’s long-term behavior, and are its most sensitive climate indicators (

On the back of substantial SMB gains over the past few years, the Greenland ice sheet looks set to continue that trend in 2019-20. From April 14 through April 18, 2020, the world’s largest island added a monster 27+ gigatons to its ice sheet. According to climate alarmists, this simply shouldn’t be happening in a warming world. In fact, it might as well not be happening as developments like these NEVER receive MSM attention, meaning alarmists are NEVER privy to the full and unalarming picture…

Les glaces terrestres, la cryosphère 3/3

by JC Maurin, 10 avril 2020 in ScienceClimatEnergie

Partie 3/3 : La diminution de la cryosphère est-elle démontrée dans l’AR5?

La contribution de la cryosphère à la hausse du niveau des mers est abordée dans le chapitre 4 du rapport AR5 du GIEC [1]. Les banquises [2] ne figurent pas parmi les contributeurs car leur fonte ne peut affecter les niveaux marins.

Le GIEC est persuadé que la masse de la cryosphère a diminué entre 1992 et 2012. Cette certitude de l’organisme intergouvernemental est fondée sur sa grande confiance dans des modèles gravimétrique/altimétrique et sur des marges d’erreur très optimistes, particulièrement en Antarctique [3] et sur les glaciers [4].

Les glaces terrestres, la cryosphère (2/3)

by J.C. Maurin, 27 mars 2020 in ScienceClimatEnergie

Partie 2/3 : Lecture critique du chapitre cryosphère de l’AR5

par J.C. Maurin, Professeur agrégé de physique

Cette deuxième partie de l’article examine la composition du chapitre 4 du 5ème rapport du GIEC (AR5) [1].
Dans ce chapitre, qui concerne les différentes composantes de la cryosphère, les banquises [2] et glaciers [3] sont particulièrement mises en avant par les rédacteurs du GIEC.
A propos de ces 2 composantes mineures (0,65 % du volume de la cryosphère), l’article développe certains éléments d’appréciation que les rédacteurs de l’AR5 n’ont pas mis en exergue.

Continuer la lecture de Les glaces terrestres, la cryosphère (2/3)

Study: Computer Models Overestimate Observed Arctic Warming

by Craig Idso, February 26, 2020 in ClimateChageDispatch

Paper Reviewed:
Huang, J., Ou, T., Chen, D., Lun, Y. and Zhao, Z. 2019. The amplified Arctic warming in recent decades may have been overestimated by CMIP5 models. Geophysical Research Letters 46: 13,338-12,345.

Policies aimed at protecting humanity and the environment from the potential effects of CO2-induced global warming rely almost entirely upon models predicting large future temperature increases.

But what if those predictions are wrong? What if a comparison between model projections and observations revealed the models are overestimating the amount of warming?

Would climate alarmists admit as much and back away from promoting extreme policies of CO2 emission reductions?

Probably not — at least based upon the recent rhetoric of each of the candidates seeking the Democrat Party’s nomination for President of the United States, all of whom continue to call for the complete elimination of all CO2 emissions from fossil fuel use within the next three decades, or less.

But for non-ideologues who are willing to examine and accept the facts as they are, the recent work of Huang et al. (2019) provides reason enough to pause the crazy CO2 emission-reduction train.

In their study, the five researchers set out to examine how well model projections of Arctic temperatures (poleward of 60°N) compared with good old-fashioned observations.

More specifically, they used a statistical procedure suitable for nonlinear analysis (ensemble empirical mode decomposition) to examine secular Arctic warming over the period 1880-2017.

Observational data utilized in the study were obtained from the HadCRUT4.6 temperature database, whereas model-based temperature projections were derived from simulations from 36 Coupled Model Intercomparison Project Phase 5 (CMIP5) global climate models (GCMs).

Figure 1. Observed and model-predicted rates of nonlinear, secular warming in the Arctic (60-90°N) over the period 1880-2017. The black and red dashed lines indicate the 10th and 90th percentiles for temperature means. Adapted from Huang et al. (2019).

As indicated there, the model-estimated rate of secular warming (the solid red line) increased quite sharply across the 138 year period, rising from a value of around 0°C per decade at the beginning of the record to a value of 0.35°C per decade in the end.

Do We Really Have Only 12 Years to Live?

by Andy May, February 23, 2020 in WUWT

Why have uninformed celebrities and politicians been telling everyone, who will listen, we are all going to die in a climate catastrophe in 10 to 30 years? U.N. General Assembly President María Fernanda Espinosa Garcés of Ecuador warned us…


However, these absurd statements are not supported by even the most fanatical climate alarmists, like Kate Marvel (NASA), Gavin Schmidt (NASA), Katharine Hayhoe (Texas Tech), or Andrea Dutton (University of Florida) (link). The original inspiration for these statements came from a 2018 IPCC report entitled Global Warming of 1.5°C. Even the alarmist Scientific American does not think the world is ending in twelve years.

We will discuss this IPCC report below, but first let’s look at some critical evidence that is not in the report. As usual the IPCC dodges the current benefits of warming and additional CO2, so we need to fill in this gap.

A little over two years ago I posted an essay entitled “Calculating the Cost of Global Warming,” it did not calculate a cost, but discussed calculations made by others. Global warming and the increasing concentration of CO2 in the atmosphere are not existential threats to mankind or to nature. Global warming will not go “runaway,” this idea, discussed here, has been discredited by climate change skeptics and by climate alarmists alike (see here and here for examples). So, given that global warming and additional CO2 will not harm us, we are reduced to a discussion of the economic impacts and benefits, both positive and negative, of global warming and additional CO2.


Figure 2. A graph of CMIP5 global tropospheric temperatures (5-year averages) versus satellite and weather balloon observations. These predictions are for the Representative Concentration Pathway (RCP) 4.5, a moderate case. Source: House of Representatives report by Dr. John Christy.

Nature Has Been Removing Excess CO2 4X Faster than IPCC Models

by Dr. Roy Spencer, February 5, 2020 in WUWT

Note: What I present below is scarcely believable to me. I have looked for an error in my analysis, but cannot find one. Nevertheless, extraordinary claims require extraordinary evidence, so let the following be an introduction to a potential issue with current carbon cycle models that might well be easily resolved by others with more experience and insight than I possess.


Sixty years of Mauna Loa CO2 data compared to yearly estimates of anthropogenic CO2 emissions shows that Mother Nature has been removing 2.3%/year of the “anthropogenic excess” of atmospheric CO2 above a baseline of 295 ppm. When similar calculations are done for the RCP (Representative Concentration Pathway) projections of anthropogenic emissons and CO2 concentrations it is found that the carbon cycle models those projections are based upon remove excess CO2 at only 1/4th the observed rate. If these results are anywhere near accurate, the future RCP projections of CO2, as well as the resulting climate model projection of resulting warming, are probably biased high.



My previous post from a few days ago showed the performance of a simple CO2 budget model that, when forced with estimates of yearly anthropogenic emissions, very closely matches the yearly average Mauna Loa CO2 observations during 1959-2019. I assume that a comparable level of agreement is a necessary condition of any model that is relied upon to predict future levels of atmospheric CO2 if it is have any hope of making useful predictions of climate change.

In that post I forced the model with EIA projections of future emissions (0.6%/yr growth until 2050) and compared it to the RCP (Representative Concentration Pathway) scenarios used for forcing the IPCC climate models. I concluded that we might never reach a doubling of atmospheric CO2 (2XCO2).

But what I did not address was the relative influence on those results of (1) assumed future anthropogenic CO2 emissions versus (2) how fast nature removes excess CO2 from the atmosphere. Most critiques of the RCP scenarios address the former, but not the latter. Both are needed to produce an RCP scenario.

I implied that the RCP scenarios from models did not remove CO2 fast enough, but I did not actually demonstrate it. That is the subject of this short article.

What Should the Atmospheric CO2 Removal Rate be Compared To?

Continuer la lecture de Nature Has Been Removing Excess CO2 4X Faster than IPCC Models


by Cap Allon, January 22, 2020 in Electroverse

According to NOAA’s own historical data, of the 50 U.S. state all-time record high temperatures, 23 were set during the 1930s, while 36 occurred prior to 1960 — climate change proponents are feeding us a fairy tale, and I’m sick of it…

The maniacal sociopaths of the world may have won control of the narrative, but they seemingly have little sway over the will of the people. You need only browse the comment section below any “climate change” article or social media post to see the wave of folks resoundingly rejecting the scam-of-a-world-view assembled before them (one of the few positives of SM).

The man-made global warming rejection is likely down to two things: the first being that the so called “scientific consensus” has been failing for far too long — you can’t start warning people in the 1980s that we have 10 years left to save the planet, only to keep repeating that prophecy for the next 4 decades. This is probably the reason our youth have become the new target — kids don’t have this history of failure to draw-upon when browsing the bullet points of the latest IPCC report -for example- meaning they’re far easier to manipulate.


The Evidence Proves That CO2 is Not a Greenhouse Gas

by Tim Ball, September 13, 2018 in Technocracy.News

The Intergovernmental Panel on Climate Change (IPCC) claim of human-caused global warming (AGW) is built on the assumption that an increase in atmospheric CO2 causes an increase in global temperature. The IPCC claim is what science calls a theory, a hypothesis, or in simple English, a speculation.  Every theory is based on a set of assumptions. The standard scientific method is to challenge the theory by trying to disprove it. Karl Popper wrote about this approach in a 1963 article, Science as Falsification. Douglas Yates said,

“No scientific theory achieves public acceptance until it has been thoroughly discredited.”

Thomas Huxley made a similar observation.

“The improver of natural knowledge absolutely refuses to acknowledge authority, as such. For him, skepticism is the highest of duties; blind faith the one unpardonable sin.”

In other words, all scientists must be skeptics, which makes a mockery out of the charge that those who questioned AGW, were global warming skeptics. Michael Shermer provides a likely explanation for the effectiveness of the charge.

“Scientists are skeptics. It’s unfortunate that the word ‘skeptic’ has taken on other connotations in the culture involving nihilism and cynicism. Really, in its pure and original meaning, it’s just thoughtful inquiry.”

The scientific method was not used with the AGW theory. In fact, the exact opposite occurred, they tried to prove the theory. It is a treadmill guaranteed to make you misread, misrepresent, misuse and selectively choose data and evidence. This is precisely what the IPCC did and continued to do.

Des observations satellitaires qui ne confirment pas les modèles climatiques

by Jean N., 3 janvier 2020 in ScienceClimatEnergie



3. Conclusions

• Depuis plus de 40 ans que des mesures de température sont effectuées par satellite, la basse et la moyenne troposphère se réchauffent bel et bien. Mais sans aucune accélération visible, et ce à des vitesses de l’ordre de +0.13°C/décade et +0.09°C/décade. La vitesse de réchauffement décroit donc avec l’altitude.

• La zone correspondant à la tropopause (vers 10 km d’altitude) ne se réchauffe pas, contrairement à ce que les modèles informatiques prédisent (pour plus de détails voir les articles de J. Christy). Peut-on alors continuer à utiliser ces modèles pour prédire la température de certaines couches atmosphériques dans le futur? Notons ici que les observations satellitaires sont confirmées par des observations réalisées in situ avec des ballons-sondes.

• La basse stratosphère se refroidit actuellement à la vitesse d’environ –0.29°C par décade, et l’analyse de corrélation menée par Varotsos et Efstathiou nous suggère que le comportement de la stratosphère n’est pas simplement lié à celui de la troposphère, les choses étant plus complexes.

• Les modèles climatiques actuels, basés sur l’hypothèse d’un l’effet de serre radiatif causé essentiellement par du CO2 atmosphérique, sont donc à revoir. Le CO2 (naturel ou d’origine anthropique) pourrait donc n’avoir qu’un rôle mineur et imperceptible sur la température de la troposphère.

En conclusion générale, nous devons toujours garder à l’esprit que le système climatique est très complexe car il est composé de cinq sous-systèmes (atmosphère, cryosphère, hydrosphère, biosphère et lithosphère) et que ces 5 sous-systèmes interagissent les uns avec les autres dans l’espace et le temps avec des processus principalement non linéaires (Lovejoy et Varotsos, 2016) et se comportent de manière chaotique (voir ici). Par conséquent, la modification d’un seul paramètre dans l’un des sous-systèmes (par exemple, la température de la basse troposphère) ne permet pas de prévoir un changement climatique à long terme, car tous les autres paramètres de l’atmosphère mais aussi ceux des autres sous-systèmes (connus et mesurables, ou non) ne sont pas nécessairement connus et stables. En plus de tout cela plusieurs facteurs externes, imparfaitement connus, peuvent influencer chacun des sous-systèmes, comme les rayonnements cosmiques ou les variations du champ magnétique solaire.

Failed Serial Doomcasting

by Willis Eschenbach, December 27, 2019 in WUWT

People sometimes ask me why I don’t believe the endless climate/energy use predictions of impending doom and gloom for the year 2050 or 2100. The reason is, neither the climate models nor the energy use models are worth a bucket of warm spit for such predictions. Folks concentrate a lot on the obvious problems with the climate models. But the energy models are just as bad, and the climate models totally depend on the energy models for estimating future emissions. However, consider the following US Energy Information Agency (EIA) predictions of energy use from 2010, quoted from here (emphasis mine):

The only thing that seems clear about all of those questions is that the answer is not “CO2”. Here’s another look at Greenland, this time with CO2 overlaid on the temperature:

The List Grows – Now 100+ Scientific Papers Assert CO2 Has A Minuscule Effect On The Climate

by K. Richard, December 12, 2019 in NoTricksZone

Within the last few years, over 50 papers have been added to our compilation of scientific studies that find the climate’s sensitivity to doubled CO2 (280 ppm to 560 ppm) ranges from <0 to 1°C. When no quantification is provided, words like “negligible” are used to describe CO2’s effect on the climate. The list has now reached 106 scientific papers.

Link: 100+ Scientific Papers – Low CO2 Climate Sensitivity

A few of the papers published in 2019 are provided below:

CMIP5 Model Atmospheric Warming 1979-2018: Some Comparisons to Observations

by Roy Spencer, December 12, 2019 in WUWT

I keep getting asked about our charts comparing the CMIP5 models to observations, old versions of which are still circulating, so it could be I have not been proactive enough at providing updates to those. Since I presented some charts at the Heartland conference in D.C. in July summarizing the latest results we had as of that time, I thought I would reproduce those here.

The following comparisons are for the lower tropospheric (LT) temperature product, with separate results for global and tropical (20N-20S). I also provide trend ranking “bar plots” so you can get a better idea of how the warming trends all quantitatively compare to one another (and since it is the trends that, arguably, matter the most when discussing “global warming”).

From what I understand, the new CMIP6 models are exhibiting even more warming than the CMIP5 models, so it sounds like when we have sufficient model comparisons to produce CMIP6 plots, the discrepancies seen below will be increasing.

Global Comparisons

First is the plot of global LT anomaly time series, where I have averaged 4 reanalysis datasets together, but kept the RSS and UAH versions of the satellite-only datasets separate. (Click on images to get full-resolution versions).

Climate Models Have Not Improved in 50 Years

by David Middleton, December 6, 2019 in WUWT

The accuracy of the failed models improved when they adjusted them to fit the observations… Shocking.

The AGU and Wiley currently allow limited access to Hausfather et al., 2019. Of particular note are figures 2 and 3. I won’t post the images here due to the fact that it is a protected limited access document.

Figure 2: Model Failure

Figure 2 has two panels. The upper panel depicts comparisons of the rates of temperature change of the observations vs the models, with error bars that presumably represent 2σ (2 standard deviations). According to my Mark I Eyeball Analysis, of the 17 model scenarios depicted, 6 were above the observations’ 2σ (off the chart too much warming), 4 were near the top of the observations’ 2σ (too much warming), 2 were below the observations’ 2σ (off the chart too little warming), 2 were near the bottom of the observations’ 2σ (too little warming), and 3 were within 1σ (in the ballpark) of the observations.

Figure 2. Equilibrium climate sensitivity (ECS) and transient climate response

L’Optimum Climatique Médiéval : ce Grand Oublié !

by A. Préat, 29 novembre 2019 in ScienceClimatEnergie

1/ Introduction

Comme rappelé dans un précédent article (ici) les événements hyperthermiques sont fréquents tout au long de l’histoire de la Terre. Bien que fréquents et étudiés avec détail, force est de reconnaître que le ‘fin’ mot de leur origine n’est toujours pas connu, sauf à leur attribuer à tous un lien de parenté avec l’un ou l’autre des gaz dits à effet de serre, sans qu’une démonstration en bonne et due forme soit présentée. C’est ce que décortique l’article paru dans SCE (ici) pour un des événements hyperthermiques les plus intenses (événement PETM pour Paleocene-Eocene Thermal Maximum) s’étant déroulé au début de l’ère Cénozoïque il y a environ 56 millions d’années.

Rappelons la succession de ces événements au Cénozoïque, d’abord l’événement PETM, ensuite E-O (Eocene-Oligocene transition with climatic shift), MMCO (Mid-Miocene Climatic Optimum), MPTO (Mid-Pliocene Thermal Optimum) et depuis environ 10 000 ans l’Optimum Holocène. Ces événements montrent tous que la Terre a régulièrement connu de longues périodes chaudes avec des ‘températures moyennes globales’ plus élevées que l’actuelle (voir par exemple Cronin 2010, également mentionné sur de nombreux sites web). L’indicateur climatique communément utilisé , la température moyenne globale est loin d’être parfait (ici et ici). Il ne faut donc pas prendre au pied de la lettre cette notion de ‘température moyenne globale’ car déjà pour aujourd’hui elle est plus que discutable, et pour le passé elle est plus qu’inconnue. Mais il n’en reste pas moins vrai que lors des événements hyperthermiques ou des optima climatiques la température était plus élevée qu’actuellement, nous le savons grâce à de nombreux indicateurs ou ‘proxies’ (voir plus loin). Ces événements ne concernent pas uniquement le Cénozoïque (y compris l’Holocène) mais l’ensemble de l’échelle des temps géologiques au-delà du Cénozoïque, avec parfois des températures fort supérieures à celles du Cénozoïque, comme par exemple au Permien (ici).

2/ L’Optimum Climatique Médieval

Revenons aux temps actuels, c’est-à-dire aux temps historiques. Plusieurs Optima Climatiques se succèdent depuis environ 6000 ans, avec pour la période la plus proche de nous, c’est-à-dire environ 3500 ans, la succession des Optima Climatiques Minoen, Romain, Médiéval et Actuel (Figure 1). Le plus récent est l’Optimum Climatique Médiéval (OCM) dont l’acmé se situe aux alentours de l’an mil. S’agissant de températures à peine plus élevées (1,5°C cfr ici et Le Roy Ladurie, 1967, également 1.0-1.4°C in Easterbrook, 2011), la délimitation précise de cet intervalle par rapport aux périodes encadrantes est difficile et l’OCM est finalement compris du 8ème au 13ème siècle (= le ‘petit optimum du Moyen Age’ d’environ 700 à 1350 sensu Le Roy Ladurie, 1967).

Figure 8 (cfr. Figure 5 in Préat, 2019). Capture d’écran de la Figure 8 de Scafetta (2019) : On the reliability of computer-based climate models. IJEGE, 19, 49-70. En comparant les deux courbes on peut se demander si l’on parle de la même chose! (RWP Roman Warm Period, DACP Dark Age Cold Period ou période froide post-romaine, MWP Medieval Warm Period, LIA Little Ice Age, CWP Current  Warm Period). Pour rappel la courbe A du haut, est la fameuse courbe en forme de hockey de Mann et al. 1998 du GIEC.

Scientists Cite Uncertainty, Error, Model Deficiencies To Affirm A Non-Detectable Human Climate Influence

by K. Richard, November 21, 2019 in NoTricksZone

Observational uncertainty, errors, biases, and estimation discrepancies in longwave radiation may be 100 times larger than the entire accumulated influence of CO2 increases over 10 years. This effectively rules out clear detection of a potential human influence on climate.

The anthropogenic global warming (AGW) hypothesis rides on the fundamental assumption that perturbations in the Earth’s energy budget – driven by changes in downward longwave radiation from CO2 — are what cause climate change.

According to one of the most frequently referenced papers advancing the position that CO2 concentration changes (and downward longwave radiation perturbations) drive surface temperature changes, Feldman et al. (2015) concluded there was a modest 0.2 W/m² forcing associated with CO2 rising by 22 ppm per decade.

Again, that’s a total CO2 influence of 0.2 W/m² over ten years.

In contrast, analyses from several new papers indicate the uncertainty and error values in downwelling (and outgoing) longwave radiation in cloudless environments are more than 100 times larger than 0.2 W/m².

In other words, it is effectively impossible to clearly discern a human influence on climate.


1.  Kim and Lee, 2019   Measurement errors of outgoing longwave radiation (OLR) reach 11 W/m², more than 50 times larger than total CO2 forcing over 10 years. Cloud optical thickness (COT) and water vapor have “the greatest effect” on OLR – an influence of 2.7 W/m². CO2 must rise to 800 ppm to impute an influence of 1 W/m².

Paris Won’t Cut Emissions–Bob Watson

by P. Homewood, November 10, 2019 in NotaLotofPeople KnowThat

It’s apparently taken ex IPCC Chair Bob Watson four years to work out that the Paris Agreement did nothing to reduce emissions.

It’s a pity he did not read this blog, because I was saying the same thing when it was signed!

Steve Milloy reports:


The truth behind the Paris Agreement climate pledges

Almost 75% of 184 Paris Agreement pledges were judged insufficient to slow climate change; Only 28 European Union nations and 7 others will reduce emissions by at least 40% by 2030


  • Only 28 European Union nations & 7 others will reduce emissions by at least 40 percent by 2030
  • China & India, top emitters, will reduce emissions intensity, but their emissions will increase
  • U.S., second top emitter, has reversed key national policies to combat climate change
  • Almost 70 percent of the pledges rely on funding from wealthy nations for their implementation

Almost three-quarters of the 184 climate pledges made under the Paris Agreement aimed at curbing greenhouse gas emissions are inadequate to slow climate change, and some of the world’s largest emitters will continue to increase emissions, according to a panel of world-class climate scientists. It is these increasing greenhouse emissions that are driving climate change.

The Truth Behind the Climate Pledges, a new report published by the Universal Ecological Fund, examines in great detail the 184 voluntary pledges under the Paris Agreement, the first collective global effort to address climate change.

New climate models – even more wrong

by P. Matthews, Nov. 5, 2019 in ClimateScepticsim

The IPCC AR5 Report included this diagram, showing that climate models exaggerate recent warming:

If you want to find it, it’s figure 11.25, also repeated in the Technical Summary as figure TS-14. The issue is also discussed in box TS3:

“However, an analysis of the full suite of CMIP5 historical simulations (augmented for the period 2006–2012 by RCP4.5 simulations) reveals that 111 out of 114 realizations show a GMST trend over 1998–2012 that is higher than the entire HadCRUT4 trend ensemble (Box TS.3, Figure 1a; CMIP5 ensemble mean trend is 0.21°C per decade). This difference between simulated and observed trends could be caused by some combination of (a) internal climate variability, (b) missing or incorrect RF, and (c) model response error.”

Well, now there is a new generation of climate models, imaginatively known as CMIP6. By a remarkable coincidence, two new papers have just appeared, from independent teams, giving very similar results and published on the same day in the same journal. One is UKESM1: Description and evaluation of the UK Earth System Model, with a long list of authors, mostly from the Met Office, also announced as a “New flagship climate model” on the Met Office website.  The other is Structure and Performance of GFDL’s CM4.0 Climate Model, by a team from GFDL and Princeton. Both papers are open-access.

Now you might think that the new models would be better than the old ones. This is mathematical modelling 101: if a model doesn’t fit well with the data, you improve the model to make it fit better. But such elementary logic doesn’t apply in the field of climate science.

Human CO2 Emissions Have Little Effect On Atmospheric CO2

by Ed Berry, October 21, 2019 in PrincipiaScientificInternational

The United Nations Intergovernmental Panel on Climate Change (IPCC) agrees human CO2 is only 5 percent and natural CO2 is 95 percent of the CO2 inflow into the atmosphere. The ratio of human to natural CO2 in the atmosphere must equal the ratio of the inflows.

Yet IPCC claims human CO2 has caused all the rise in atmospheric CO2 above 280 ppm, which is now 130 ppm or 32 percent of today’s atmospheric CO2.

To cause the human 5 percent to become 32 percent in the atmosphere, the IPCC model treats human and natural CO2 differently, which is impossible because the molecules are identical. IPCC’s Bern model artificially traps human CO2 in the atmosphere while it lets natural CO2 flow freely out of the atmosphere.

By contrast, a simple Physics Model treats all CO2 molecules the same, as it should, and shows how CO2 flows through the atmosphere and produces a balance level where outflow equals inflow. Thereafter, if inflow is constant, level remains constant.

The Physics Model has only one hypothesis, that outflow is proportional to level. The Physics Model exactly replicates the 14C data from 1970 to 2014 with only two physical parameters: balance level and e-time. The 14C data trace how CO2 flows out of the atmosphere.

The Physics Model shows the 14CO2 e-time is a constant 16.5 years. Other data show e-time for 12CO2 is about 4 to 5 years. IPCC claims human CO2 reduces ocean buffer capacity. But that would increase e-time. The constant e-time proves IPCC’s claim is false.

IPCC argues that the human-caused reduction of 14C and 13C in the atmosphere prove human CO2 causes all the increase in atmospheric CO2. However, numbers show these isotope data support the Physics Model and reject the IPCC model.

The Physics Model shows how inflows of human and natural CO2 into the atmosphere set balance levels proportional to their inflows. Each balance level remains constant if its inflow remains constant. Continued constant CO2 emissions do not add more CO2 to the atmosphere. No CO2 accumulates in the atmosphere.

Present human CO2 inflow produces a balance level of about 18 ppm. Present natural CO2 inflow produces a balance level of about 392 ppm. Human CO2 is insignificant to the increase of CO2 in the atmosphere. Increased natural CO2 inflow has increased the level of CO2 in the atmosphere.

Keywords: carbon dioxide, CO2, climate change, anthropogenic