Archives par mot-clé : IPCC

How IPCC’s 1990 Predictions Expensively Failed

by C. Monckton of Brenchley, Nov 8, 2022 in WUWT

It is now almost a third of a century since 1990, when IPCC made its first predictions about the weather. Since IPCC (2021) continues to predict the same 3 C° midrange long-term warming (equilibrium doubled-CO2 sensitivity, or ECS, broadly equivalent to 20th-century anthropogenic warming from all sources) as in 1990, it is high time someone examined IPCC’s medium-term predictions to shed light on the plausibility of its long-term predictions.

IPCC’s key medium-term prediction in 1990 was as follows –

“Based on current model results, we predict:

  • “under the IPCC Business-as-Usual (Scenario A) emissions of greenhouse gases, a rate of increase of global mean temperature during the next century of about 0.3 C° per decade (with an uncertainty range of 0.2 C° to 0.5 C° per decade). This is greater than that seen over the past 10,000 years. This will result in a likely increase in global mean temperature of about 1 C° above the present value by 2025 and 3 C° before the end of the next century. The rise will not be steady because of the influence of other factors.”

IPCC also predicted as follows –

This second business-as-usual prediction was that there would be 1.8 C° warming from preindustrial times to 2030. Deducting the 0.45 C° warming up to 1990, the prediction amounted to 1.35 C° or about 0.34 C°/decade. Thus, IPCC predicted 0.3-0.34 C°/decade medium-term warming. However, only 0.14 C°/decade has occurred since 1990

he IPCC’s Climate Math Doesn’t Add Up. Will Anyone Notice?

by R. McKitrick, Oct 14, 2022 in ClimateChangeDispatch

The high and rising costs of climate policy — now including the inability of jurisdictions that bet big on renewables to guarantee enough energy for their citizens to survive the coming winter — don’t just entitle us to question the basis for it: they demand we do so.

Ultimately, the justification for renewables is the view that carbon dioxide emissions have a big effect on the climate that will cause devastating harm at some point in the future. [bold, links added]

Scientists measure the effect using a concept called “Equilibrium Climate Sensitivity” or ECS, which estimates how much long-run average warming will occur as a result of doubling the amount of carbon dioxide in the atmosphere.

Some important new evidence pointing to a low ECS value just emerged in the scientific literature.

ECS has long been uncertain. In 1979 the U.S. National Academy of Sciences estimated it to be between 1.5 and 4.5 degrees Celsius, with a best estimate of 3.0 degrees C.

That range, which runs from “no big deal” to “very bad outcomes,” was accepted by the UN Intergovernmental Panel on Climate Change (IPCC) in its first report in 1990 and thereafter until 2007 when, citing greater warming projections in newer models, it raised the bottom end to 2.0 degrees C.

But over the next few years, literature developed using, not model simulations, but observed warming rates since the late-1800s to estimate ECS.

Its results typically centered around 2.0 C or less. So in 2013, the IPCC reduced the bottom end of the range back to 1.5 C and declined to offer a best estimate. In other words, after three decades climate science hadn’t narrowed the uncertainty at all.

The economic implications of ECS being 2 C rather than 3 C are enormous.

Regime Pseudoscientists Enforce Climate Change Narrative

by M. Rectenwald, Oct 12, 2022 in ClimateChangeDispatch

It does this by pathologizing said subjects and their views.

For example, the field has been mobilized to discredit so-called conspiracy theorists by attempting to identify the mistaken mental processes that conspiracy theorists exhibit. [bold, links added]

The methods and results of such studies have proven to be less than stellar, to say the least.

Now, the field is also being wielded to discredit “climate change deniers.”1 By pathologizing the thinking processes of these stubbornly mistaken subjects, the views of said subjects can be safely dismissed.

After all, the theory of anthropogenic climate change (ACC) is obviously true, or so says the Intergovernmental Panel on Climate Change (IPCC), the planetary authority on the matter.

Likewise, those who doubt or deny ACC must be crazy. The point of psychological studies is to discover just what is wrong with these people and how, if possible, to change their minds.

Of course, such studies focus exclusively on the “deniers,” without ever considering climate change believers and whether something is wrong with them. The field lacks even a semblance of symmetry.

Never mind that “the science” is dubious or that climate change is ludicrously being blamed for heart attacks, obesity in children, increased violence, and terrorism, among other medical and social maladies.

Believing in a causal connection between a questionable climate change theory and these phenomena must be perfectly rational, according to this kind of research.

Such is the thrust of a recent study of Australian climate change skeptics conducted by a lecturer in psychology and a professor of geology at the University of the Sunshine Coast.

Entitled “Associations of Locus of Control, Information Processing Style and Anti-reflexivity with Climate Change Scepticism in an Australian Sample,” the study examines climate change skeptics in terms of thinking styles rather than “values” and “sociodemographic” factors.

Since past research has found values and sociodemographic factors to be intractable, the researchers in this study seek to identify factors that presumably can be changed and that should likewise prove useful for the study.

Satellite Temperature Data Show Almost All Climate Model Forecasts Over the Last 40 Years Were Wrong

by C. Morrison, Oct 8, 2022 in DailySceptic

A major survey into the accuracy of climate models has found that almost all the past temperature forecasts between 1980-2021 were excessive compared with accurate satellite measurements. The findings were recently published by Professor Nicola Scafetta, a physicist from the University of Naples. He attributes the inaccuracies to a limited understanding of Equilibrium Climate Sensitivity (ECS), the number of degrees centigrade the Earth’s temperature will rise with a doubling of carbon dioxide.

Scientists have spent decades trying to find an accurate ECS number, to no avail. Current estimates range from 0.5°C to around 6-7°C. Without knowing this vital figure, the so-called ‘settled’ science narrative around human-caused climate change remains a largely political invention, not a credible scientific proposition. Professor Scafetta has conducted extensive work into climate models and is a long-time critic of their results and forecasts. In a previous work, he said many of the climate models should be “dismissed and not used by policymakers”. Along with around 250 professors, he is a signatory to the World Climate Declaration which states there is no climate emergency and also notes climate models are “not remotely plausible as global tools”.

Scafetta’s latest work grouped 38 major climate models into low, medium and high ECS values, ranging between 1.8°C and 5.7°C. He found that models in the medium and high category “ran hot” in over 95% and 97% of cases respectively. The lower models were said to have done better when compared to global warming calculated for the period by the major surface datasets of 0.52-0.58°C. But the UAH satellite data showed warming up to 30% less during this period, suggesting even the low warming models produced “excessive warming” from 1980-2021.

According to Scafetta, these results are showed that the ECS figure could be as low as 1.2-2°C. Particular concern is expressed about surface temperature records that “appear to be severely affected by non-climatic warming biases”. Scafetta concludes that surface-based temperature records are likely to be affected by warming biases, such as the urban heat island effect due to expanding urban development, and subject to natural oscillations that are not reproduced by climate models. He concludes: “The global warming expected for the next few decades may be even more moderate than predicted by the low ECS-GCMs [Global Circulation Models], and could easily fall within a safe temperature range where climate adaptation policies will suffice.”


See also : Satellite Temperature Data Show Almost All Climate Model Forecasts Over the Last 40 Years Were Wrong

Press Release: Important new paper challenges IPCC’s claims about climate sensitivity

by P. Homewood, Sep 20, 2022 in NotaLotofPeopleKnowThat

London, 20 September – A new paper reduces the estimate of climate sensitivity – the amount of warming expected for a doubling of carbon dioxide concentrations – by one third. The results therefore suggest that future global warming will be much less than expected.
The paper, by independent scientist Nic Lewis, has just appeared in the journal Climate Dynamics. It is an important challenge to the official view of the Intergovernmental Panel on Climate Change (IPCC).
Lewis has critiqued a 2020 assessment of climate sensitivity by Sherwood et al., which strongly influenced the IPCC’s Sixth Assessment Report, in 2021. Lewis commented:
“It is unfortunate that Sherwood et al.’s assessment of climate sensitivity, which underpinned the UN Framework Convention on Climate Change, contained such serious errors, inconsistencies and deficiencies in its methods”.
After correcting the Sherwood et al. methods and revising key input data to reflect, primarily, more recent evidence, the central estimate for climate sensitivity comes down from 3.1°C per doubling of CO2 concentration in the original study to 2.16°C in the new paper.
This large reduction shows how sensitive climate sensitivity estimates still are to input assumptions, and that values between 1.5°C and 2°C remain quite plausible.

  • Climate sensitivity represents the long-term global temperature increase caused by a doubling of atmospheric CO2 concentration. There are different measures of climate sensitivity. Both the Sherwood and Lewis papers estimate the so-called ‘effective’ climate sensitivity, which reflects a new equilibrium state projected from centennial changes after a doubling of the CO2 concentration. This measure is considered the most relevant one for predicting climate change in the coming two centuries.
  • Climate sensitivity has always been a very important, but also highly uncertain, parameter in the climate change discourse. Earlier IPCC reports assessed its value as likely to be somewhere between 1.5°C and 4.5°C, with a best estimate of 3°C. However, prompted by the Sherwood paper, the 2021 Sixth Assessment Report moved that range upwards, to 2.5 to 4°C. Although for outsiders this might sound boring, for insiders it was a revolutionary change.
  • Lewis’s corrections and revisions lead to a likely range of 1.75 to 2.7°C, which is not only lower but is also much less uncertain than either the 2021 official IPCC assessment or the very similar Sherwood et al. estimate (2.6 to 3.9°C).
  • Nic Lewis is the lead or sole author of ten peer-reviewed papers on climate sensitivity. He was a participant in the 2015 workshop that kicked off the World Climate Research Programme project that led to the Sherwood et al. 2020 paper, but he was not a co-author of that paper.

Lewis commented:
“The substantial reduction in assessed climate sensitivity upon updating key input data suggests that the increase in the bottom of the climate sensitivity range in the IPCC Sixth Assessment Report was unjustified”.
Lewis’s paper is entitled ‘Objectively combining climate sensitivity evidence’. It can be freely downloaded here. A detailed explanatory article about the paper is available here.

DEBUNKED: Europe’s claimed ‘worst drought in 500 years’

by P. Homewood,  Aug 20, 2022  , in NotaLotofPeopleKnowThat

Roger Pielke Jr debunks Europe’s “Worst Drought in 500 Years Claim”:



In Western and Central Europe — basically Atlantic France all the way to Moscow, north of the Mediterranean region and south of the North Sea region — the IPCC and the underlying peer reviewed research on which it assesses has concluded that drought has not increased and, logically, that increased drought cannot be attributed to human-caused climate change. The only exception here is that the IPCC has medium confidence in an increasing trend of soil moisture deficits in some subregions, however the IPCC has low confidence that this trend can be attributed to human-caused climate change. Looking to future, at temperature changes of 2C and more, at present the IPCC does not expect the current state of scientific understandings to change. But stay tuned — that’s why we do science.

The full post is here.

See also : DEBUNKED: Europe’s claimed ‘worst drought in 500 years’ – Peer-reviewed studies, data & IPCC reveal ‘drought has not increased’ & ‘cannot be attributed to human-caused climate change’

Is Global Warming The Greatest Scientific Fraud In History?

by G.K. Mitchell, Aug 19, 202 in ClimateChangeDispatch

In its seminal report in 1990, the U.N. IPCC stated that “at the then current rate of world emissions of CO2, the global mean temperature would likely increase by 1°C by 2025.

This statement formed the basis for the hypothesis that anthropogenic (man-made) global warmingresulted from the increased concentration of CO2 in the Earth’s lower atmosphere resulting from man-made activities.

Central to the hypothesis was that the temperature of the lower troposphere would increase as the concentration of CO2 in the troposphere increased.

Therefore, in its 1990 report, the U.N. IPCC established a direct linkage between the concentration of CO2 in the atmosphere and the temperature of the lower troposphere.

The scientific method of inquiry has guided scientific research and investigation for over 400 years. In summary, the scientific method requires that a researcher observe a phenomenon, postulate a hypothesis for the cause of the phenomenon, and then conduct experiments or scientific investigations to falsify the hypothesis.

In adherence to the scientific method, a climate scientist who thinks that man has caused global warming should develop a complex hypothesis as follows:

  1. Global warming has occurred; that is, the temperature of the world’s oceans, landmass, and relevant atmosphere has risen during the period under investigation by a statistically significant amount.

  2. Man’s activities are responsible for the global warming that has occurred.

  3. The extent to which global warming has occurred, or is reasonably projected to occur in the future, will adversely affect life on Earth.

If any of the conjectures in the complex hypothesis above are found to be invalid, the complex hypothesis is determined to be falsified and either discarded or modified.

Tim Ball: The Evidence Proves That CO2 is Not a Greenhouse Gas

by T. Ball, Sept 13, 2018 in Technocracy


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.

A theory is used to produce results. The results are not wrong, they are only as right as the assumptions on which they are based. For example, Einstein used his theory of relativity to produce the most famous formula in the world; e = mc2. You cannot prove it wrong mathematically because it is the end product of the assumptions he made. To test it and disprove it, you challenge one or all of the assumptions. One of these is represented by the letter “c” in the formula, which assumes nothing can travel faster than the speed of light. Scientists challenging the theory are looking for something moving faster than the speed of light.

Biden falsely links Kentucky floods to ‘climate change’ – Reality Check: Floods ‘have not increased in frequency or intensity’ – White House ignores peer-reviewed studies & IPCC & data

by M. Morano, Aug 11, 2022 in WUWT

Study in the Journal of Hydrology finds no increase in floods – ‘Compelling evidence for increased flooding at a global’ scale is lacking’

Extreme Weather expert Dr. Roger Pielke Jr. comments on new study: ‘New empirical study: Are floods increasing in North America and Europe? No (and consistent with IPCC.)’

Study published in the Journal of Hydrology, Volume 552, September 2017, Pages 704-717. The study found:

‘The number of significant trends was about the number expected due to chance alone.’

‘Changes in the frequency of major floods are dominated by multidecadal variability.’

‘The Intergovernmental Panel on Climate Change (IPCC) concluded (Hartmann et al., 2013) that globally there is no clear and widespread evidence of changes in flood magnitude or frequency in observed flood records.’

‘The results of this study, for North America and Europe, provide a firmer foundation and support the conclusion of the IPCC (Hartmann et al., 2013) that compelling evidence for increased flooding at a global scale is lacking.’

Little evidence of changes in extreme weather trends

by P. Homewood, July 27, 2022 in NotaLotofPeopleKnowThat

New IPCC attribution statistics are distorting observational evidence

London, 27 July – A new paper from the Global Warming Policy Foundation finds that the IPCC’s recent shift in methodology has led to misleading claims about changes in weather extremes.

The review, from physicist Dr Ralph Alexander, finds that IPCC claims that many of these weather extremes are increasing significantly are largely unsupported by observational evidence.

Ralph Alexander: Extreme Weather: The IPCC’s Changing Tune (pdf)

According to Dr Alexander:
“On almost every kind of extreme weather, with the possible exemption of heatwaves, the evidence for significant changes is scant. But the latest IPCC report has introduced novel ‘attribution’ statistics and now insists that things are getting worse. It’s yet another case of scientists trying to scare the public into compliance.”

Dr Alexander’s paper looks at:
– droughts
– floods
– hurricanes
– tornadoes
– wildfires
– hot and cold extremes
– coral bleaching.

He concludes that:
“The mistaken belief that weather extremes are worsening because of climate change is more a perception, fostered by media coverage, than reality. The IPCC’s new statistical method is playing an unworthy part in bringing this sorry state of affairs to pass.”

GWPF invited the Royal Society and the Met Office to review this paper, and to submit a response to be published as an appendix to it. No reply was received.

The IPCC And The Infamous Hockey Stick Graph

by CCD Editor, July 25,2022 in ClimateChangeDispatch

Ron Barmby, author of  “Sunlight on Climate Change: A Heretic’s Guide to Global Climate Hysteria” (AmazonBarnes & Noble) spoke with Mike Ryan of TNT Radio (TNT Radio ( about what he uncovered in the recent IPCC report, Climate Change 2021: The Physical Sciences Basis.

Ron’s findings: after being made famous by Al Gore and adopted by the IPCC, then being made infamous by its historical and statistical failings and subsequently dropped by the IPCC, the hockey stick temperature graph is back!

And a new narrative is being introduced that carbon dioxide has been demoted to causing only half of human global warming to date.

Mike discusses with Ron the four things wrong, and often in conflict with, the report itself with the latest doomsday science from the IPCC. LISTEN:

…IPCC Summary Report, Part 2…

by D. Dears, July 2022 in PowerForUsa


The politicians changed the report written by the scientists so that it would be consistent with the SPM written by the politicians.

The report now reads:

“The body of statistical evidence in chapter 8 … now points towards a discernible human influence on global climate.”

Whereas it originally read:

“No study to date has positively attributed all or part (of the climate warming observed) to (manmade) causes.”

As a result, the pubic was told there is a discernible human influence on global climate when the scientists said none had been positively identified.

A legitimate scientific organization wouldn’t allow politicians to overrule scientists.

Why would our country rely on such an organization?

Link to Amicus Curiae

Use this link in an email to let others know about this article 

Climate Change Weekly #439: Hurricanes Not Increasing, Despite Warming

by H.S. Burnett, Jul 1, 2022 in WUWT

Pielke notes five points of fact about hurricanes:

  1. The Intergovernmental Panel on Climate Change (IPCC) finds “no consensus” on the relative role of human influences on Atlantic hurricane activity, quoting the IPCC as follows: “there is still no consensus on the relative magnitude of human and natural influences on past changes in Atlantic hurricane activity, … and it remains uncertain whether past changes in Atlantic TC activity are outside the range of natural variability.”
  2. “The IPCC has concluded that since 1900 there is ‘no trend in the frequency of USA landfall events.’ This goes for all hurricanes and also for the strongest hurricanes, called major hurricanes.”
  3. “Since at least 1980, there are no clear trends in overall global hurricane and major hurricane activity.”
  4. “There are many characteristics of tropical cyclones that are under study and hypothesized to be potentially affected by human influences, … but at present there is not a unified community consensus on these hypotheses, as summarized by the World Meteorological Organization,” as to whether any of the factors are affected by human greenhouse gas emissions.
  5. “Hurricanes are common, incredibly destructive and will always be with us. Even so, we have learned a lot about how to prepare and recover.”

Pielke points out that some of the costliest hurricanes occurred in the early part of the twentieth century when average global temperatures were cooler than at present.

Code Red For Sanity – The Credibility Crisis At The IPCC

by R. Barmby, Jun23, 2022 in ClimateChangeDispatch

When speaking about the Intergovernmental Panel on Climate Change (IPCC) report Climate Change 2021: The Physical Sciences Basis, UN Secretary-General António Guterres declared it a “code red for humanity.”

He further stressed, “The alarm bells are deafening, and the evidence is irrefutable.” [bold, links added]

But a person who reads the report dispassionately and thoroughly will recognize that there is no code red for humanity and that the evidence is indeed refutable. It would be more accurate to say the report is a code red for sanity.

Classical science observes what is; that’s the evidence. A political agenda persuades what should be done; that’s the alarm bells.

Let’s turn off the alarm the IPCC pulled by examining Climate Change 2021: The Physical Science Basis (referred to from this point as “the report”).

You’ll discover that while the report contains some scientific evidence, much of it is hidden, manipulated, or contradicted.

Because of this, we’ll refute the so-called evidence in the report by explaining how the science has been misrepresented.

Let’s bring sanity back to science.

The report has four major themes where the political agenda has overrun classical science.

Theme 1: Climate history was altered.

The IPCC would like you to believe that the Earth’s temperature has been constant for thousands of years and that the approximate 1°C of warming is unprecedented.

The report offers this figure to support that view:

Why IPCC Climate Forecasts Are So Dodgy

by R. Barmy, May 5, 2022 in ClimateChangeDispatch

This is the fourth in a series of articles on the IPCC’s AR6 WG1 report. –CCD ed.

Margaret Thatcher helped create the United Nations Intergovernmental Panel on Climate Change (IPCC) in 1988. As an Oxford-trained chemist, she understood scientific principles and was concerned that we “… do not live at the expense of future generations.”

By 2002, the Iron Lady turned against global warming extremism by stating in her book Statecraft: Strategies for a Changing World, “What is far more apparent is that the usual suspects on the left have been exaggerating the dangers and simplifying solutions in order to press their agenda…” [bold, links added]

Thatcher’s comments of exaggeration and simplification were a prescient critique of the IPCC report Climate Change 2021: The Physical Sciences Basis.

The IPCC uses computer simulations to predict climate dangers and test solutions. An important step in the computer simulation of a real-world physical process is making sure the simulator can replicate the known history of that physical process.

If a computer model can accurately replicate a significant history of a known process, called hindcasting, it lends credibility that the correct equations are being used and will be able to predict future events.

AR6 Model Failure Affirmed: ‘No Model Group Succeeds Reproducing Observed Surface Warming Patterns’

by K. Richard, Apr 25, 2022 in NoTricksZone

A new study published in Geophysical Research Lettershighlights the abysmal model performance manifested in the latest Intergovernmental Panel on Climate Change report (AR6). The 38 CMIP6 general circulation models (GCMs) fail to adequately simulate even the most recent (1980-2021) warming patterns over 60 to 81% of the Earth’s surface.

Dr. Scafetta places particular emphasis on the poor performance of the highly uncertain estimates (somewhere between 1.83 and 5.67°C) of equilibrium climate sensitivity (ECS) and their data-model agreement relative to 1980-2021 global warming patterns.

The worst-performing ECS estimates are the ones projecting 3-4.5°C and 4.5-6°C warming in response to doubled CO2 concentrations (to 560 ppm) plus feedbacks, as the 1980-2021 temperature trends are nowhere close to aligning with these trajectories.

Instead, the projected global warming by 2050 (~2°C relative to 1750) associated with the lowest ECS estimates and implied by the warming observed over the last 40+ years is characterized as “unalarming” even with the most extreme greenhouse gas emissions (no mitigation efforts undertaken) growth rate.

In addition to the conclusion that “no model group succeeds reproducing observed surface warming patterns,” poor modeling of heat transfer physics, ocean and atmospheric circulation patterns, polar sea ice processes…is also evident in the latest IPCC report.

“Accurately reproducing regional temperature differences over the past 40+ years is beyond the capability of climate model simulations, and even fails for major ocean basins and continents.”

The fundamental modeling failures in simulating responses to sharply rising greenhouse gas emissions over the last 40+ years “calls into question model-based attribution of climate responses to anthropogenic forcing.”

Climate Past Far From Settled: 7 Major Temperature Reconstructions Find No Agreement

by P. Gosselin, Mar 29, 2022 in WUWT    

new paper published in open access publishing MDPI looks at seven prominent hemispheric and global temperature reconstructions for the past 2000 years (T2k).

The analysis conducted by the authors found that some reconstructions “differed from each other in some segments by more than 0.5 °C” whilst some show negligible pre-industrial climate variability (“hockey sticks”).

Those showing variability would suggest natural factors playing a greater role than those that claim climate had been rather constant over the past 2000 years.

Abstract: Global mean annual temperature has increased by more than 1 °C during the past 150 years, as documented by thermometer measurements. Such observational data are, unfortunately, not available for the pre-industrial period of the Common Era (CE), for which the climate development is reconstructed using various types of palaeoclimatological proxies. In this analysis, we compared seven prominent hemispheric and global temperature reconstructions for the past 2000 years (T2k) which differed from each other in some segments by more than 0.5 °C. Whilst some T2k show negligible pre-industrial climate variability (“hockey sticks”), others suggest significant temperature fluctuations. We discuss possible sources of error and highlight three criteria that need to be considered to increase the quality and stability of future T2k reconstructions. Temperature proxy series are to be thoroughly validated with regards to (1) reproducibility, (2) seasonal stability, and (3) areal representativeness. The T2k represents key calibration data for climate models. The models need to first reproduce the reconstructed pre-industrial climate history before being validated and cleared for climate projections of the future. Precise attribution of modern warming to anthropogenic and natural causes will not be possible until T2k composites stabilize and are truly representative for a well-defined region and season. The discrepancies between the different T2k reconstructions directly translate into a major challenge with regards to the political interpretation of the climate change risk profile. As a rule of thumb, the larger/smaller the pre-industrial temperature changes, the higher/lower the natural contribution to the current warm period (CWP) will likely be, thus, reducing/increasing the CO2 climate sensitivity and the expected warming until 2100.

A Brief Summary Of How ‘Global Warming’ Science Has Changed Since 1998

by K. Richard, Mar 31, 2022 in NoTricksZone

Two weeks before Dr. Michael E. Mann and colleagues published their 23 April 1998 “hockey stick” chart in Nature, a peer-reviewed journal published a paper asserting “an overwhelming majority of climate scientists” (50 out of 60) view catastrophic human-caused global warming – and even global warming itself – as an “unsupported assumption”.

At the time, satellite data indicated the lower troposphere had cooled by 0.13°C between 1979 and 1994. The Arctic had cooled by -0.88°C since the 1940s.

It was thought the IPCC had just (1995) perpetrated a “disturbing corruption of the peer-review process” in manipulating the conclusions of scientists to support favored government policies.

New Study: The CO2-Drives-Global-Warming ‘Concept’ Is ‘Obsolete And Incorrect’

by Lightfoot & Ratzer,  Mar 14, 2022 in NoTricksZone/JBasicApplSci

In analyzing UAH global temperature and Mauna Loa CO2 records from 1979 to 2021, climate researchers Lightfoot and Ratzer (2022) report there has been “little, if any” correlation between these two variables during this period.

They assert that between 91 and 98% of Earth’s greenhouse gas effect is from water vapor, as CO2 and other trace gases contribute less than 5% to greenhouse gas forcing.

A solar minimum has just began in the current solar cycle 25. The declining solar output is projected to eventually lead to a ~1 to 1.2°C cooling over the next 30 to 40 years. Solar minimum periods are also accompanied by crop failures due to frost and weather extremes delivering excessive heat.

The authors conclude by suggesting the popularized conceptualization of CO2 as a driver of global warming has proven to be “obsolete and incorrect”.

New Study: The CO2-Drives-Global-Warming ‘Concept’ Is ‘Obsolete And Incorrect’

by K. Richard, Mar 14, 2022 in NoTricksZone

“The IPCC concept that increasing carbon dioxide in the atmosphere causes global warming is three decades out-of-date.”  − Lightfoot and Ratzer (2022), Journal of Basic & Applied Sciences

In analyzing UAH global temperature and Mauna Loa CO2 records from 1979 to 2021, climate researchers Lightfoot and Ratzer (2022) report there has been “little, if any” correlation between these two variables during this period.

They assert that between 91 and 98% of Earth’s greenhouse gas effect is from water vapor, as CO2 and other trace gases contribute less than 5% to greenhouse gas forcing.

A solar minimum has just began in the current solar cycle 25. The declining solar output is projected to eventually lead to a ~1 to 1.2°C cooling over the next 30 to 40 years. Solar minimum periods are also accompanied by crop failures due to frost and weather extremes delivering excessive heat.

The authors conclude by suggesting the popularized conceptualization of CO2 as a driver of global warming has proven to be “obsolete and incorrect”.

Image Source: Lightfoot and Ratzer, 2022

Pielke Jr. on IPCC AR6 WG2 Release

by Pielke Jr., Feb28, 2022 in WUWT

An initial thread on the IPCC AR6 WG2 report released today

Whereas WG1 received a mixed review in my areas of expertise (specifically: poor on scenarios, solid on extremes), my initial reaction to the WG2 report is that it is an exceedingly poor assessment

The first observation is that the report is more heavily weighted to implausible scenarios than any previous IPCC assessment report

In particular, RCP8.5 represents ~57% of scenario mentions

This alone accounts for the apocalyptic tone and conclusions throughout the report.

IPCC WGII AR6, More Insanity: Small Islands

by K. Hansen, March 1, 2022 in WUWT

A Shocking Lack of Evidence for Shocking Claims

The IPCC has rushed out a new portion of the IPCC WGII Sixth Assessment Report: Climate Change 2022: Impacts, Adaptation and Vulnerability.  The report itself and all of its summaries and chapters are available from the IPCC web site.  I say rushed out because when I downloaded Chapter 15: Small Islandsat 5:00 pm EST on February 28th, the copy I received was still marked “Accepted Version Subject to Final Edits” and “Do Not Cite, Quote or Distribute”.

They are quite right to mark it “Do Not Cite, Quote or Distribute”  —  I would have suggested expanding that to “Do Not Cite, Quote, Distribute, or Read”.   But, that would be a personal opinion.  I am afraid I failed to follow my own best advice and have made the mistake of reading Chapter 15:  Small Islands.  So, having failed to “not read” I will follow up by failing to not cite, quote or distribute potions in this Opinion essay.

The IPCC CO2 Climate Narrative: A “Behemoth On Clay Feet” …Ready To Collapse

by P. Gosselin, Fab, 6, 2022 in NoTricksZone

The earth’s history provides the solid proof that acquits CO2. The IPCC’s claim of CO2 being the dominant climate factor is a behemoth on clay feet. 

By Fred F. Mueller

Have you ever had an uneasy feeling when watching the aggressive, intolerant stance of the apologists of “man-made climate catastrophe” against all critics?

The overwhelming majority of our elites blame CO2 emitted by mankind to be responsible for “a runaway overheating” of our atmosphere. “The science” spearheaded by the Intergovernmental Panel on Climate Change (IPCC) calls for us to renounce fossil fuels and return to the frugal lifestyle of the 18th or 19th century.

You might well find you’re not alone with that unease, which is proliferating rapidly since social media giants have started to censor people daring to question the IPCC’s “science is settled” attitude.

New Research: “CO2 Influence On Global Temperature Development Since1860 Only Half As Large As IPCC Estimate!

by  F. Vahrenholt, Dec 14, 2021 in NoTricksZone

On November 3, 2021, the renowned scientific journal Climate published a paper on solar influence on climate.

The paper by the renowned solar researcher Dr. Frank Stefani from the Helmholtz Zentrum Dresden-Rossendorf is entitled: “Solar and Anthropogenic Influences on Climate: A Regression Analysis and Tentative Predictions” and concludes that the influence of CO2 on the development of global temperatures from 1860 until today was only about half as large as the last report of the Intergovernmental Panel on Climate Change (IPCC) assumed.

As a reminder, the IPCC concludes that 98% of the warming ( 1.07 degrees out of 1.09 degrees) is human-induced. According to Stefani’s analysis, the solar influence accounts for 30-70%.

Stefani examined the course of the geomagnetic aa – index, which reflects the strength of the earth’s magnetic field. This index has been measured in Cambridge and Melbourne since 1844 and reflects the influence of solar activity. In earlier publications, Stefani had already been able to prove that the 11-year solar cycle is triggered by the gravitational forces of Venus, Earth and Jupiter, which are in orbital resonance every 11.07 years (here, here and here).

Since the Sun – influenced by all the planets (especially Jupiter and Saturn) – also moves around the center of gravity of the solar system, solar cycles arise that have become known in temperature history as the 193-year Suess-de Vries cycle and the 90-year Gleissberg cycle.

46 STATEMENTS By IPCC Experts Against The IPCC

by Jamie Spry, Dec 2019, in Climatism

THANKFULLY we usually always get to hear the inconvenient and raw truth about taxpayer funded, unelected, bloated government bureaucracies when members eventually leave and are not subject to bullying and financial repercussions. Definitely no exception here…

46 enlightening statements by IPCC experts against the IPCC:

  1. Dr Robert Balling: The IPCC notes that “No significant acceleration in the rate of sea level rise during the 20th century has been detected.” This did not appear in the IPCC Summary for Policymakers.
  2. Dr Lucka Bogataj: “Rising levels of airborne carbon dioxide don’t cause global temperatures to rise…. temperature changed first and some 700 years later a change in aerial content of carbon dioxide followed.”
  3. Dr John Christy: “Little known to the public is the fact that most of the scientists involved with the IPCC do not agree that global warming is occurring. Its findings have been consistently misrepresented and/or politicized with each succeeding report.”
  4. Dr Rosa Compagnucci: “Humans have only contributed a few tenths of a degree to warming on Earth. Solar activity is a key driver of climate.”
  5. Dr Richard Courtney: “The empirical evidence strongly indicates that the anthropogenic global warming hypothesis is wrong.”
  6. Dr Judith Curry: “I’m not going to just spout off and endorse the IPCC because I don’t have confidence in the process.”
  7. Dr Robert Davis: “Global temperatures have not been changing as state of the art climate models predicted they would. Not a single mention of satellite temperature observations appears in the IPCC Summary for Policymakers.”
  8. Dr Willem de Lange: “In 1996 the IPCC listed me as one of approximately 3000 “scientists” who agreed that there was a discernible human influence on climate. I didn’t. There is no evidence to support the hypothesis that runaway catastrophic climate change is due to human activities.”
  9. Dr Chris de Freitas: “Government decision-makers should have heard by now that the basis for the long-standing claim that carbon dioxide is a major driver of global climate is being questioned; along with it the hitherto assumed need for costly measures to restrict carbon dioxide emissions. If they have not heard, it is because of the din of global warming hysteria that relies on the logical fallacy of ‘argument from ignorance’ and predictions of computer models.”
  10. Dr Oliver Frauenfeld: “Much more progress is necessary regarding our current understanding of climate and our abilities to model it.”
  11. Dr Peter Dietze: “Using a flawed eddy diffusion model, the IPCC has grossly underestimated the future oceanic carbon dioxide uptake.”
  12. Dr John Everett: “It is time for a reality check. The oceans and coastal zones have been far warmer and colder than is projected in the present scenarios of climate change. I have reviewed the IPCC and more recent scientific literature and believe that there is not a problem with increased acidification, even up to the unlikely levels in the most-used IPCC scenarios.”
  13. Dr Eigil Friis-Christensen: “The IPCC refused to consider the sun’s effect on the Earth’s climate as a topic worthy of investigation. The IPCC conceived its task only as investigating potential human causes of climate change.”
  14. Dr Lee Gerhard: “I never fully accepted or denied the anthropogenic global warming concept until the furore started after NASA’s James Hansen’s wild claims in the late 1980s. I went to the [scientific] literature to study the basis of the claim, starting with first principles. My studies then led me to believe that the claims were false.”
  15. Dr Indur Goklany: “Climate change is unlikely to be the world’s most important environmental problem of the 21st century. There is no signal in the mortality data to indicate increases in the overall frequencies or severities of extreme weather events, despite large increases in the population at risk.”
  16. Dr Vincent Gray: “The [IPCC] climate change statement is an orchestrated litany of lies.”
  17. Dr Mike Hulme: “Claims such as ‘2500 of the world’s leading scientists have reached a consensus that human activities are having a significant influence on the climate’ are disingenuous … The actual number of scientists who backed that claim was only a few dozen.”
  18. Dr Kiminori Itoh: “There are many factors which cause climate change. Considering only greenhouse gases is nonsense and harmful.”
  19. Dr Yuri Izrael: “There is no proven link between human activity and global warming. I think the panic over global warming is totally unjustified. There is no serious threat to the climate.”
  20. Dr Steven Japar: “Temperature measurements show that the climate model-predicted mid-troposphere hot zone is non-existent. This is more than sufficient to invalidate global climate models and projections made with them.”
  21. Dr Georg Kaser: “This number [of receding glaciers reported by the IPCC] is not just a little bit wrong, it is far out by any order of magnitude … It is so wrong that it is not even worth discussing.”
  22. Dr Aynsley Kellow: “I’m not holding my breath for criticism to be taken on board, which underscores a fault in the whole peer review process for the IPCC: there is no chance of a chapter [of the IPCC report] ever being rejected for publication, no matter how flawed it might be.”
  23. Dr Madhav Khandekar: “I have carefully analysed adverse impacts of climate change as projected by the IPCC and have discounted these claims as exaggerated and lacking any supporting evidence.”
  24. Dr Hans Labohm: “The alarmist passages in the IPCC Summary for Policymakers have been skewed through an elaborate and sophisticated process of spin-doctoring.”
  25. Dr Andrew Lacis: “There is no scientific merit to be found in the Executive Summary. The presentation sounds like something put together by Greenpeace activists and their legal department.”
  26. Dr Chris Landsea: “I cannot in good faith continue to contribute to a process that I view as both being motivated by pre-conceived agendas and being scientifically unsound.”
  27. Dr Richard Lindzen: “The IPCC process is driven by politics rather than science. It uses summaries to misrepresent what scientists say and exploits public ignorance.”
  28. Dr Harry Lins: “Surface temperature changes over the past century have been episodic and modest and there has been no net global warming for over a decade now. The case for alarm regarding climate change is grossly overstated.”
  29. Dr Philip Lloyd: “I am doing a detailed assessment of the IPCC reports and the Summaries for Policy Makers, identifying the way in which the Summaries have distorted the science. I have found examples of a summary saying precisely the opposite of what the scientists said.”
  30. Dr Martin Manning: “Some government delegates influencing the IPCC Summary for Policymakers misrepresent or contradict the lead authors.”
  31. Steven McIntyre: “The many references in the popular media to a ‘consensus of thousands of scientists’ are both a great exaggeration and also misleading.”
  32. Dr Patrick Michaels: “The rates of warming, on multiple time scales, have now invalidated the suite of IPCC climate models. No, the science is not settled.”
  33. Dr Nils-Axel Morner: “If you go around the globe, you find no sea level rise anywhere.”
  34. Dr Johannes Oerlemans: “The IPCC has become too political. Many scientists have not been able to resist the siren call of fame, research funding and meetings in exotic places that awaits them if they are willing to compromise scientific principles and integrity in support of the man-made global-warming doctrine.”
  35. Dr Roger Pielke: “All of my comments were ignored without even a rebuttal. At that point, I concluded that the IPCC Reports were actually intended to be advocacy documents designed to produce particular policy actions, but not a true and honest assessment of the understanding of the climate system.”
  36. Dr Paul Reiter: “As far as the science being ‘settled,’ I think that is an obscenity. The fact is the science is being distorted by people who are not scientists.”
  37. Dr Murry Salby: “I have an involuntary gag reflex whenever someone says the science is settled. Anyone who thinks the science is settled on this topic is in fantasia.”
  38. Dr Tom Segalstad: “The IPCC global warming model is not supported by the scientific data.”
  39. Dr Fred Singer: “Isn’t it remarkable that the Policymakers Summary of the IPCC report avoids mentioning the satellite data altogether, or even the existence of satellites — probably because the data show a slight cooling over the last 18 years, in direct contradiction of the calculations from climate models?”
  40. Dr Hajo Smit: “There is clear cut solar-climate coupling and a very strong natural variability of climate on all historical time scales. Currently I hardly believe anymore that there is any relevant relationship between human CO2 emissions and climate change.”
  41. Dr Richard Tol: “The IPCC attracted more people with political rather than academic motives. In AR4, green activists held key positions in the IPCC and they succeeded in excluding or neutralising opposite voices.”
  42. Dr Tom Tripp: “There is so much of a natural variability in weather it makes it difficult to come to a scientifically valid conclusion that global warming is man made.”
  43. Dr Gerd-Rainer Weber: “Most of the extremist views about climate change have little or no scientific basis.”
  44. Dr David Wojick: “The public is not well served by this constant drumbeat of alarms fed by computer models manipulated by advocates.”
  45. Dr Miklos Zagoni: “I am positively convinced that the anthropogenic global warming theory is wrong.”
  46. Dr Eduardo Zorita: “Editors, reviewers and authors of alternative studies, analysis, interpretations, even based on the same data we have at our disposal, have been bullied and subtly blackmailed.”

Via : 46 statements by IPCC experts against the IPCC | grumpydenier



  1. Dr Robert C Balling, Jr.  Dr Robert Ballingis a professor of geography at Arizona State University, and the former director of its Office of Climatology. His research interests include climatology, global climate change, and geographic information systems. Balling has declared himself one of the scientists who oppose the consensus on global warming, arguing in a 2009 book that anthropogenic global warming “is indeed real, but relatively modest”, and maintaining that there is a publication bias in the scientific literature.

  2. Dr Lucka Bogataj (Kajfež Bogataj Lučka) The joint recipient of the Nobel Peace Prize in 2007, she is one of Slovenia’s pioneers in researching the impact of climate change, and she regularly informs the general public of her findings.She is a full professor and teaches at the Biotechnical Faculty, while also lecturing at the Faculty of Mathematics and Physics and at the Faculty of Architecture. More…