Archives par mot-clé : Model(s)

Can Computer Models Predict Climate?

by Dr C. Essex, Apr 13,  2022 in BigPicturesNews


Guest post by Christopher Essex, Emeritus Professor of Mathematics and Physics, University of Western Ontario.

Christopher Essex

By Dr Christopher Essex

It is well known that daytime winter temperatures on Earth can fall well below -4°F (-20℃ ) in some places, even in midlatitudes, despite warming worries. Sometimes the surface can even drop below -40°F (-40℃ ), which is comparable to the surface of Mars. What is not so well known is that such cold winter days are colder than they would be with no atmosphere at all!

How can that be if the atmosphere is like a blanket, according to the standard greenhouse analogy? If the greenhouse analogy fails, what is climate?

Climate computer models in the 1960s could not account for this non-greenhouse-like picture. However modern computer models are better than those old models, but the climate implications of an atmosphere that cools as well as warms has not been embraced. Will computer models be able to predict climate after it is? The meteorological program for climate has been underway for more than 40 years. How did it do?

Feynman, Experiment and Climate Models
“Model” is used in a peculiar manner in the climate field. In other fields, models are usually formulated so that they can be found false in the face of evidence. From fundamental physics (the Standard Model) to star formation, a model is meant to be put to the test, no matter how meritorious.

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“The IPCC concept that increasing carbon dioxide in the atmosphere causes global warming is three decades out-of-date.”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

German Paper: “A Mild Additional Temperature Rise Of Around 1°K”… Drop Not Excluded By 2100!

by P. Gosselin, Mar 6, 2022 in NoTricksZone


In its most recent video, German site Die kalte Sonne here looks at a paper on CO2 climate forcing by Stefani 2021: Solar and Anthropogenic Influences on Climate: Regression Analysis and Tentative Predictions. The results point to only a moderately warming planet up to the year 2150.

To hype up climate warming alarm, IPCC scientists like to exaggerate CO2’s power to trap heat and warm up the atmosphere. But with every assessment report that the IPCC issues, the estimated value by which CO2 warms the planet steadily gets reduced as the observed warming keeps lagging behind what earlier models predicted.

In his paper, Frank Stefani and his team at the Helmholtz Center, Institute of Fluid Dynamics in Dresden, Germany looked at the impacts by CO2 and solar activity.

On average 1.1°C warming

Using double regression, the scientists evaluated linear combinations of the logarithm of the carbon dioxide concentration and the geomagnetic aa index as a proxy for solar activity. They reproduced the sea surface temperature (HadSST) since the middle of the 19th and ended up with a a climate sensitivity (of TCR type) in the range of 0.6 K until 1.6 K per doubling of CO2. The midpoint of this range is 1.1°C, a value many critical climate scientists have already estimated earlier, and thus far below the IPCC scary estimates.

The paper’s abstract elaborates further:

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.

Why We Must “Quit Worrying About Uncertainty in Sea Level Projections”

by K. Hansen, Dec 2, 2021 in CO2Coalition


It is an interesting read but not because it presents good advice to the scientific community.  Rather, it presents the case that climate and ice models, which are used to make projections, are not up to the task.  While those who program climate models have been trained in what we know about the basic physics involved in the biggest sea level rise issue – ice sheet dynamics – the actual projections by those models depend on parameters that are loose guesses about things we don’t know.  As a result, Bassis says “…recent studies using climate and ice sheet models are, more and more often, coming to very different conclusions about future rates of sea level rise and even about the sensitivity of ice sheets to future warming…”  and because of that, he tells us:

“Large discrepancies among model projections of long-term sea level rise have spawned calls among the scientific community for scientists to work on reducing uncertainty. However, focusing on uncertainty is a trap we must avoid. Instead, we should focus on the adaptation decisions we can already make on the basis of current models and communicating and building confidence in models for longer-term decisions.”

Kip Hansen is an expert on sea level and sea-level rise. Prolific author of numerous articles on the subjects. WUWT lists 445 commentaries and articles.

He has spent much of his adult life at sea, first as an officer on a merchant ship, and later as a USCG-licensed captain in the Caribbean, where he sailed with his wife while doing humanitarian work (mostly Dominican Republic).

He is a proud member of the CO2 Coalition.

 This commentary was first published by the CO2 Coalition, December 3, 2021

Physicists: Climate Model Error Overestimates CO2 Impact On Global Temps By Factor Of 5

by K. Richard, Nov 22, 2021 in NoTricksZone


A new study suggests CO2 molecules have little consequential impact affecting outgoing radiation, and that climate models attribute global temperature effects to CO2 that are fundamentally erroneous.

Russian physicists (Smirnov and Zhilyaev, 2021) have published a peer-reviewed paper in the Advances in Fundamental Physics Special Issue for the journal Foundations.

They assesses the role of CO2 molecules in the standard atmosphere and assert “we have a contradiction with the results of climatological models in the analysis of the Earth’s greenhouse effect.”

Key points from the paper include the following:

1. Climate model calculations of CO2’s impact on global temperatures are in error by a factor of 5 as a result of “ignoring, in climatological models, the Kirchhoff law” which says radiators are “simultaneously the absorbers.”

2. Change in the concentration of an optically active atmospheric component (like CO2) “would not lead to change in the outgoing radiative flux.”

3. CO2 molecules “are not the main radiator of the atmosphere.” Water vapor molecules are, and thus they “may be responsible for the observed heating of the Earth.”

How good have climate models been at truly predicting the future?

by Gavin, Dec 4, 2019 in RealClimate


A new paper from Hausfather and colleagues (incl. me) has just been published with the most comprehensive assessment of climate model projections since the 1970s. Bottom line? Once you correct for small errors in the projected forcings, they did remarkably well.

Climate models are a core part of our understanding of our future climate. They also have been frequently attacked by those dismissive of climate change, who argue that since climate models are inevitably approximations they have no predictive power, or indeed, that they aren’t even scientific.

In an upcoming paper in Geophysical Research Letters, Zeke Hausfather, Henri Drake, Tristan Abbott and I took a look at how well climate models have actually been able to accurately project warming in the years after they were published. This is an extension of the comparisons we have been making on RealClimate for many years, but with a broader scope and a deeper analysis. We gathered all the climate models published between 1970 and the mid-2000s that gave projections of both future warming and future concentrations of CO2 and other climate forcings – from Manabe (1970) and Mitchell (1970) through to CMIP3 in IPCC 2007.

We found that climate models – even those published back in the 1970s – did remarkably well, with 14 out of the 17 projections statistically indistinguishable from what actually occurred.

We evaluated these models both on how well modeled warming compared with observed warming after models were published, and how well the relationship between warming and CO2 (and other climate forcings) in models compares to observations (the implied transient climate response) (see Figure). The second approach is important because even if an old model had gotten all the physics right, the future projected warming would be off if they assumed we would have 450 ppm CO2 in 2020 (which some did!). Future emissions depend on human societal behavior, not physical systems, and we can usefully distinguish evaluation of climate models physics from paths of future concentrations.

Figure 2 from Hausfather et al (2019) showing the comparisons between model predictions and observations for a) the temperature trends (above) and b) the implied Transient Climate Response (TCR) which is the trend divided by the forcing and scaled to an equivalent 2xCO2 forcing.

Critical Solar Factors Ignored…IPCC AR6 Covers Up Scientific Flaws In Climate Models

by P. Gosselin, Aug 22, 2021 in NoTricksZone


According to the latest IPCC Assessment Report 6 (AR6), the observed temperature increase and the calculated temperature increase according to climate models have been almost the same 1.3 °C from 1750 to 2020.  The report shows a strong positive trend in solar shortwave radiation from 9/2000 to  6/2017, but its impact has been omitted in post-2000 warming calculations which explains the high temperatures since El Nino of 2015-2016.

For example, the temperature effect in 2019 is about 0.7 °C according to the AR6 science. Actually, the IPCC models give a 2019 temperature increase of 2.0°C (1.3°C + 0.7°C). This 54 percent error is due to the positive water feedback applied in climate models, which doubles the impact of other climate forcings and which, according to this natural experiment by climate, does not exist.

The amount of carbon dioxide in the atmosphere has increased by 32% since 1750. According to the AR6, this is only due to man-made anthropogenic emissions staying there (remain, accumulate) by an average of 44% per year and the rest has been absorbed by oceans and vegetation.

Approximately 25% of the atmospheric carbon dioxide changes annually from the oceans and vegetation. As a result, less than 6% of the initial amount of carbon dioxide in the atmosphere remains after 10 years, and therefore the increased amount of carbon dioxide in the atmosphere cannot be entirely anthropogenic origin with a permille value of -28%. The IPCC remains silent on permille values, as in the AR6 there is no word “permille”, which is a measure of the ratio of carbon isotopes and it has been used to analyze the origin of carbon dioxide, suitable for validating carbon cycle models.

Cover-up

The cover-up of this issue continues with the anthropogenic carbon dioxide lifetime in the atmosphere, which is now vaguely from hundreds of years to thousands of years. The removal rate of radioactive carbon from the atmosphere (a perfect tracer test for anthropogenic carbon dioxide) after 1964 is only 64 years. The recovery time of the total atmospheric amount of carbon dioxide to the level of 1750 can be estimated to be similar to that of its accumulation period, i.e. just under 300 years.

The AR6 report no longer shows the IPCC’s very own definition of the greenhouse effect, except in the glossary. The definition no longer contains the description for how greenhouse gas absorption of 158 Wm-2, which causes the greenhouse effect, creates downward infrared radiation downwards on the ground of 342 Wm-2. This is against fundamental physical laws because energy comes from nothing. The radiation to the surface consists of four energy fluxes, which according to the IPCC’s energy balance are: greenhouse gas absorption of 158 Wm-2, latent water heat 82 Wm-2, sensible heat (warm air) 21 Wm-2, and solar radiation absorption in the atmosphere 80 Wm-2. The three firstly mentioned energy fluxes totaling 261 Wm-2 maintain the greenhouse effect.

Fudging the forcings

The IPCC’s attribution methodology is fundamentally flawed

by R. McKitrick, Aug 18, 2021 in ClimateEtc.


One day after the IPCC released the AR6 I published a paper in Climate Dynamics showing that their “Optimal Fingerprinting” methodology on which they have long relied for attributing climate change to greenhouse gases is seriously flawed and its results are unreliable and largely meaningless. Some of the errors would be obvious to anyone trained in regression analysis, and the fact that they went unnoticed for 20 years despite the method being so heavily used does not reflect well on climatology as an empirical discipline.

My paper is a critique of “Checking for model consistency in optimal fingerprinting” by Myles Allen and Simon Tett, which was published in Climate Dynamics in 1999 and to which I refer as AT99. Their attribution methodology was instantly embraced and promoted by the IPCC in the 2001 Third Assessment Report (coincident with their embrace and promotion of the Mann hockey stick). The IPCC promotion continues today: see AR6 Section 3.2.1. It has been used in dozens and possibly hundreds of studies over the years. Wherever you begin in the Optimal Fingerprinting literature (example), all paths lead back to AT99, often via Allen and Stott (2003). So its errors and deficiencies matter acutely.

The abstract of my paper reads as follows:

New Confirmation that Climate Models Overstate Atmospheric Warming

by R. McKitrick, Aug 17, 2021 in ClimateEtc


Two new peer-reviewed papers from independent teams confirm that climate models overstate atmospheric warming and the problem has gotten worse over time, not better. The papers are Mitchell et al. (2020) “The vertical profile of recent tropical temperature trends: Persistent model biases in the context of internal variability”  Environmental Research Letters, and McKitrick and Christy (2020) “Pervasive warming bias in CMIP6 tropospheric layers” Earth and Space Science. John and I didn’t know about the Mitchell team’s work until after their paper came out, and they likewise didn’t know about ours.

Mitchell et al. look at the surface, troposphere and stratosphere over the tropics (20N to 20S). John and I look at the tropical and global lower- and mid- troposphere.  Both papers test large samples of the latest generation (“Coupled Model Intercomparison Project version 6” or CMIP6) climate models, i.e. the ones being used for the next IPCC report, and compare model outputs to post-1979 observations. John and I were able to examine 38 models while Mitchell et al. looked at 48 models. The sheer number makes one wonder why so many are needed, if the science is settled. Both papers looked at “hindcasts,” which are reconstructions of recent historical temperatures in response to observed greenhouse gas emissions and other changes (e.g. aerosols and solar forcing). Across the two papers it emerges that the models overshoot historical warming from the near-surface through the upper troposphere, in the tropics and globally.

How Climate Scenarios Lost Touch With Reality

by R. Pielke Jr & J. Ritchie, Aug, 4, 2021 in CO2Coalition


A failure of self-correction in science has compromised climate science’s ability to provide plausible views of our collective future.

The integrity of science depends on its capacity to provide an ever more reliable picture of how the world works. Over the past decade or so, serious threats to this integrity have come to light. The expectation that science is inherently self-correcting, and that it moves cumulatively and progressively away from false beliefs and toward truth, has been challenged in numerous fields—including cancer research, neuroscience, hydrology, cosmology, and economics—as observers discover that many published findings are of poor quality, subject to systemic biases, or irreproducible.

In a particularly troubling example from the biomedical sciences, a 2015 literature review found that almost 900 peer-reviewed publications reporting studies of a supposed breast cancer cell line were in fact based on a misidentified skin cancer line. Worse still, nearly 250 of these studies were published even after the mistaken cell line was conclusively identified in 2007. Our cursory search of Google Scholar indicates that researchers are still using the skin cancer cell line in breast cancer studies published in 2021. All of these erroneous studies remain in the literature and will continue to be a source of misinformation for scientists working on breast cancer.

In 2021, climate research finds itself in a situation similar to breast cancer research in 2007. Our research (and that of several colleagues) indicates that the scenarios of greenhouse gas (GHG) emissions through the end of the twenty-first century are grounded in outdated portrayals of the recent past. Because climate models depend on these scenarios to project the future behavior of the climate, the outdated scenarios provide a misleading basis both for developing a scientific evidence base and for informing climate policy discussions. The continuing misuse of scenarios in climate research has become pervasive and consequential—so much so that we view it as one of the most significant failures of scientific integrity in the twenty-first century thus far. We need a course correction.

In calling for this change, we emphasize explicitly and unequivocally that human-caused climate change is real, that it poses significant risks to society and the environment, and that various policy responses in the form of mitigation and adaptation are necessary and make good sense. However, the reality and importance of climate change does not provide a rationale or excuse for avoiding questions of research integrity any more than does the reality and importance of breast cancer. To the contrary, urgency makes attention to integrity that much more important.

Scenarios and baselines

Are Climate Feedbacks Strongly Non-Linear?

by Bob Irvine, Aug 3, 2021 in WUWT


Is it possible that the Earth’s system is strongly buffered with strong positive ice and dust feedbacks prevailing at colder temperatures, and strong negative convection/evaporation feedbacks prevailing in warmer times?

Feedback Factor (FF) is defined as the total temperature change at equilibrium for a given forcing divided by the calculated “no feedback” temperature from that forcing.

The term CO2 will be used here to represent all the non-compressing GHGs. (CO2, MH4, N2O, CFCs, HCFs etc.)

Claim: Machine Learning can Detect Anthropogenic Climate Change

E. Worrall, July 8, 2021 in WUWT


According to the big computer we are doomed to suffer ever more damaging weather extremes. But researchers can’t tell us exactly why, because their black box neural net won’t explain its prediction.

As an IT expert who has built commercial AI systems, I find it incredible that the researchers seem so naive as to think their AI machine output has value, without corroborating evidence. They admit they are going to try to understand how their AI works – but in my opinion they have jumped the gun, making big claims on the basis of a black box result.

Consider the following;

….

Gavin’s Falsifiable Science

by W. Eschenbach, Apr 2020 in WUWT


Gavin Schmidt is a computer programmer with the Goddard Institute of Space Sciences (GISS) and a noted climate alarmist. He has a Ph.D. in applied mathematics. He’s put together a twitter threadcontaining what he sees as some important points of the “testable, falsifiable science that supports a human cause of recent trends in global mean temperature”. He says that the slight ongoing rise in temperature is due to the increase in carbon dioxide (CO2) and other so-called “greenhouse gases”. For simplicity, I’ll call this the “CO2 Roolz Temperature” theory of climate. We’ve discussed Dr. Schmidt’s ideas before here on WUWT.

Now, Gavin and I have a bit of history. We first started corresponding by way of a climate mailing list moderated by Timo Hameraanta back around the turn of the century, before Facebook and Twitter.

The interesting part of our interaction was what convinced me that he was a lousy programmer. I asked him about his program, the GISS Global Climate Model. I was interested in how his model made sure that energy was conserved. I asked what happened at the end of each model timestep to verify that energy was neither created nor destroyed.

He said what I knew from my own experience in writing iterative models, that there is always some slight imbalance in energy from the beginning to the end of the timestep. If nothing else, the discrete digital nature of each calculation assures that there with be slight roundoff errors. If these are left uncorrected they can easily accumulate and bring the model down.

He said the way that the GISS model handled that imbalance was to take the excess or the shortage of energy and sprinkle it evenly over the entire planet.

Now, that seemed reasonable for trivial amounts of imbalance coming from digitization. But what if it were larger, and it arose from some problem with their calculations? What then?

So I asked him how large that energy imbalance typically was … and to my astonishment, he said he didn’t know.

Amazed, I asked if he had some computer version of a “Murphy Gauge” on the excess energy. A “Murphy Gauge” (below) is a gauge that allows for Murphy’s Law by letting you set an alarm if the variable goes outside of the expected range … which of course it will, Murphy says so. On the computer, the equivalent would be something in his model that would warn him if the excess or shortage of energy exceeded some set amount.

Yet Another Model-Based Claim Of Anthropogenic Climate Forcing Collapses

by K. Richard, Feb 25 2021 in NoTricksZone


High-resolution climate models have projected a “decline of the Atlantic Meridional Overturning Circulation (AMOC) under the influence of anthropogenic warming” for decades (Lobelle et al., 2020). New research that assesses changes in the deeper layers of the ocean (instead of “ignoring” these layers like past models have) shows instead that the AMOC hasn’t declined for over 30 years.

The North Atlantic has been rapidly cooling in recent decades (Bryden et al., 2020, Fröb et al., 2019). A cooling of “more than 2°C” in just 8 years (2008-2016) and a cooling rate of -0.78°C per decade between 2004 and 2017 has been reported for nearly the entire ocean region just south of Iceland. The cooling persists year-round and extends from the “surface down to 800 m depth”

CMIP6 and AR6, a preview

by Andy May, Feb 11, 2021 in WUWT


The new IPCC report, abbreviated “AR6,” is due to come out between April 2021 (the Physical Science Basis) and June of 2022 (the Synthesis Report). I’ve purchased some very strong hip waders to prepare for the events. For those who don’t already know, sturdy hip waders are required when wading into sewage. I’ve also taken a quick look at the CMIP6 model output that has been posted to the KNMI Climate Explorer to date. I thought I’d share some of what I found.

Meet The Team Shaking Up Climate Models

by C. Rotter, Jan 26, 2021 in WUWT


A new team tries a new approach to Climate Modeling using AI and machine learning. Time will tell if a positive effort or extremely complicated exercise in curve fitting. Their goal is regional scale predictive models useful for planning. Few admit publicly that these do not exist today despite thousands of “studies” using downscaled GCM’s.

“There are some things where there are very robust results and other things where those results are not so robust,” says Gavin Schmidt, who heads NASA’s respected climate modeling program at the Goddard Institute for Space Studies. But the variances push skeptics to dismiss the whole field.

“There’s enough stuff out there that people can sort of cherry-pick to support their preconceptions,” says Dr. Hausfather. “Climate skeptics … were arguing that climate models always predict too much warming.” After studying models done in the past 50 years, Dr. Hausfather says, “it turns out they did remarkably well.”

But climate modelers acknowledge accuracy must improve in order to plot a way through the climate crisis. Now, a team of climatologists, oceanographers, and computer scientists on the East and West U.S. coasts have launched a bold race to do just that.

They have gathered some of the brightest experts from around the world to start to build a new, modern climate model. They hope to corral the vast flow of data from sensors in space, on land, and in the ocean, and enlist “machine learning,” a kind of artificial intelligence, to bring their model alive and provide new insight into what many believe is the most pressing threat facing the planet.

Their goal is accurate climate predictions that can tell local policymakers, builders, and planners what changes to expect by when, with the kind of numerical likelihood that weather forecasters now use to describe, say, a 70% chance of rain.

Failing Computer Models

by P. Homewood ,Jan 21, 2021 in NotaLotofPeopleKnowThat


If anybody tries to tell you that the computer models are accurately predicting global warming, show them this:

http://www.remss.com/research/climate/#:~:text=The%20RSS%20merged%20lower%20stratospheric%20temperature%20data%20product,in%20well-mixed%20greenhouse%20gases%20causes%20by%20human%20activity.

It comes from RSS, who monitor atmospheric temperatures via satellite observation. They are ardent warmists, and here us what they have to say:

….

New Climate Models (CMIP6) Offer No Improvement, Model Discrepancies As Large As The Last Version (CMIP5)

by K. Richard, Dec 24, 2020 in NoTricksZone


The “unsatisfactorily large” magnitude of the discrepancies between models in estimating the various radiative contributions to Earth’s energy imbalance serves to undermine confidence that CO2’s small impact could even be detected amid all the uncertainty.

Scientists have engaged in offering their educated guesses, or estimates, of cloud radiative effects for decades.

In the latest models, CMIP6, the top of atmosphere (TOA) net cloud radiative effects (CRE) when considering clouds’ longwave and shortwave combined impact is somewhere between -17 W/m² and -31 W/m² (Wild, 2020). That’s a 14 W/m²spread in CRE modeling.

The discrepancy range between modeled estimates for downward longwave clear-sky radiation is 22.5 W/m². This is the component where CO2’s underwhelming 0.2 W/m² per decade impact (Feldman et al., 2015) is manifested. Modeling discrepancies are thus more than 100 times larger than CO2’s forcing contribution over a 10-year period.

Climate Scientists Admit Clouds are Still a Big Unknown

by E. Worrall, Sep 12, 2020 in WUWT


The authors assert that if we had a better understanding clouds, the spread of model predictions could be reduced. But there is some controversy about how badly cloud errors affect model predictions, and that controversy is not just limited to climate alarmists.

Pat Frank, who produced the diagram at the top of the page in his paper “Propagation of Error and the Reliability of Global Air Temperature Projections“, argues that climate models are unphysical and utterly unreliable, because they contain known model cloud physics errors so large the impact of the errors dwarfs the effect of rising CO2. My understanding is Pat believes large climate model physics errors have been hidden away via a dubious tuning process, which adds even more errors to coerce climate models into matching past temperature observations, without fixing the original errors.

Climate skeptic Dr. Roy Spencer disagrees with Pat Frank; Dr. Spencer suggests the cloud error biases hilighted by Pat Frank are cancelled out by other biases, resulting in a stable top of atmosphere radiative balance. Dr. Spencer makes it clear that he also does not trust climate model projections, though for different reasons to Pat Frank.

Other climate scientists like the authors of the study above, Paulo Ceppi and Ric Williams, pop up from time to time and suggest that clouds are a significant problem, though Paulo and Ric’s estimate of the scale of the problem appears to be well short of Pat Frank’s estimate.

Whoever is right, I think what is abundantly clear is the science is far from settled.

New confirmation that climate models overstate atmospheric warming

by Dr. Judith Curry, August 27, 2020 in WUWT


Reposted from Dr. Judith Curry’s Climate Etc.

Posted on August 25, 2020

by Ross McKitrick

Two new peer-reviewed papers from independent teams confirm that climate models overstate atmospheric warming and the problem has gotten worse over time, not better.

The papers are Mitchell et al. (2020) “The vertical profile of recent tropical temperature trends: Persistent model biases in the context of internal variability” Environmental Research Letters, and McKitrick and Christy (2020) “Pervasive warming bias in CMIP6 tropospheric layers” Earth and Space Science. John and I didn’t know about the Mitchell team’s work until after their paper came out, and they likewise didn’t know about ours.

Mitchell et al. look at the surface, troposphere and stratosphere over the tropics (20N to 20S). John and I look at the tropical and global lower- and mid- troposphere. Both papers test large samples of the latest generation (“Coupled Model Intercomparison Project version 6” or CMIP6) climate models, i.e. the ones being used for the next IPCC report, and compare model outputs to post-1979 observations. John and I were able to examine 38 models while Mitchell et al. looked at 48 models. The sheer number makes one wonder why so many are needed, if the science is settled. Both papers looked at “hindcasts,” which are reconstructions of recent historical temperatures in response to observed greenhouse gas emissions and other changes (e.g. aerosols and solar forcing). Across the two papers it emerges that the models overshoot historical warming from the near-surface through the upper troposphere, in the tropics and globally.

Mitchell et al. 2020

Mitchell et al. had, in an earlier study, examined whether the problem is that the models amplify surface warming too much as you go up in altitude, or whether they get the vertical amplification right but start with too much surface warming. The short answer is both.

Scientists: It’s ‘Impossible’ To Measure Critical Cloud Processes…Observations 1/50th As Accurate As They Must Be

by K. Richard, August 20, 2020 in NoTricksZone


Clouds dominate as the driver of changes in the Earth’s radiation budget and climate. A comprehensive new analysis suggests we’re so uncertain about cloud processes and how they affect climate we can’t even quantify our uncertainty. 

According to scientists (Song et al., 2016), the total net forcing for Earth’s oceanic atmospheric greenhouse effect (Gaa) during 1992-2014 amounted to -0.04 W/m² per year. In other words, the trend in total longwave forcing had a net negative (cooling) influence during those 22 years despite a 42 ppm increase in CO2. This was primarily due to the downward trend in cloud cover that overwhelmed or “offset” the longwave influence from CO2.

Cloud impacts on climate are profound – but so are uncertainties

The influence of clouds profoundly affects Earth’s radiation budget, easily overwhelming CO2’s impact within the greeenhouse effect. This has been acknowledged by scientists for decades.

Despite the magnitude of clouds’ radiative impact on climate, scientists have also pointed out that our limited capacity to observe or measure cloud effects necessarily results in massive uncertainties.

For example, Stephens et al. (2012) estimated the uncertainty in Earth’s annual longwave surface fluxes is ±9 W/m² (~18 W/m²) primarily due to the uncertainties associated with cloud longwave radiation impacts.

An Industry Out of Control: 13 Major Climate Reports in 2020, and 42 Minor Reports

by E. Worrall, August 21, 2020 in WUWT


Yale Climate Connections has listed 13 major climate reports published this year, like it is a good thing. But at least 6 of the major reports received funding from US taxpayers.

The reports listed by Yale:

State of the Climate 2019: Special Supplement to the Bulletin of the American Meteorological Society, edited by J. Blunden and D.S. Arndt (BAMS 2020, 435 pages, free download available here; a 10-page executive summary is also available) – paid for by taxpayers via NOAA

The First National Flood Risk Assessment: Defining America’s Growing Risk, by Flood Modelers (First Street Foundation 2020, 163 pages, free download available here) – not sure who pays for First Street Foundation

World Water Development Report 2020: Water and Climate Change, by UN Water (UN Educational, Scientific, and Cultural Organization 2020, 235 pages, free download available here) – paid for by taxpayers via the United Nations.

The State of Food Security and Nutrition in the World 2020: Transforming Food Systems for Affordable Healthy Diets, by FAO, IFAD, UNICEF, WFP and WHO (United Nations 2020, 320 pages, free download available here) – paid for by taxpayers via United Nations.

WHO Global Strategy on Health, Environment, and Climate Change: The Transformation Need to Improve Lives and Wellbeing through Healthy Environments, by WHO (UN-WHO 2020, 36 pages, free download available here) – paid for by taxpayers via United Nations

Cooling Emissions and Policy Synthesis Report: Benefits of Cooling Efficiency and the Kigali Amendment, by UNEP-IEA (UNEP and IEA 2020, 50 pages, free download available here) – paid for by taxpayers via the United Nations

The 2035 Report: Plummeting Solar, Wind, and Battery Costs Can Accelerate Our Clean Electricity Future, by Sonia Aggarwal and Mike O’Boyle (Goldman School of Public Policy 2020, 37 pages, free download available here) – Goldman school was started by a charitable donation, so may still be privately funded.

Addressing Climate as a Systemic Risk: A Call to Action for U.S. Financial Regulators, by Veena Ramani (Ceres 2020, 68 pages, free download available here, registration required). Not sure who paid. Ceres Foundation is a tax exempt group based in Switzerland, who appear to function as a meta charity – they provide a vehicle for people who want to create a charitable fund without having to set everything up themselves.

Gender, Climate & Security: Sustaining Inclusive Peace on the Frontlines of Climate Change, by UN Women (UN Environment & Development Programs 2020, 52 pages, free download available here) – paid for by taxpayers via the United Nations.

Evicted by Climate Change: Confronting the Gendered Impacts of Climate-Induced Displacement, by Care International (Care International 2020, 33 pages, free download available here) – Care International receives a lot of funding from taxpayers via the EU and the United Nations.

EARTH’S ATMOSPHERE HAS NO “WALLS” OR “LID” — GREENHOUSE GAS THEORY IS BOTH MATHEMATICALLY AND PHYSICALLY WRONG

by Cap Allon, July 30, 2020 in Electroverse


“The CO2 greenhouse effect of the Earth’s atmosphere is a pure fiction of people who like to use large computers, without physical bases.” — Gerhard Gerlich ph.D.

Over the years, scientific paper after scientific paper has contended the entire foundation of the man-made global-warming theory is wrong. However, those in control of the agenda selectively choose which papers/theories the public can hear about, and, in turn, which get swept under the rug.

One such paper the ill-informed street-sheep have likely never heard of is that published in the journal “Environment Pollution and Climate Change” back in 2017–the “door-opener to a new paradigm,” former IPCC reviewer Nils-Axel Mörner is quoted as calling it (Mörner left the UN after realizing it was not truly interested in science).

New Insights on the Physical Nature of the Atmospheric Greenhouse Effect Deduced from an Empirical Planetary Temperature Model” argues that concentrations of CO2 and other supposed “greenhouse gases” in the atmosphere have virtually no effect on the earth’s temperature — it concludes the entire greenhouse gas theory is incorrect.

As reported by wnd.com, the prevailing theory on the earth’s temperature is that heat from the Sun enters the atmosphere, and then greenhouse gases such as CO2, methane, and water vapor trap part of that energy by preventing it from escaping back into space.

That theory, which underpins the anthropogenic global-warming hypothesis and the climate models used by the United Nations, was first proposed and developed in the 19th century.

Climate Predictions “Worse Than We Thought”

by P.J. Michaels, July 14, 2020 in RealClearEnergy


As the temperature of the eastern U.S. normally reaches its summer maximum around the last week of July, every year at this time we are bombarded with tired “climate change is worse than we thought” (WTWT) stories. These stories take time to produce, from imagination to final copy to editing to publication, so they have usually been submitted well in advance of the summer peak. Hence, orchestrated fear.

For once, I’m in agreement about the WTWT meme, but it’s about the climate models, not the climate itself.