Archives par mot-clé : CO2

To what extent are temperature levels changing due to greenhouse gas emissions?

by J.K. Dagsvik & S.H. Moen,  Nov  2023 in  StatisticsNorway


Weather and temperatures vary in ways that are difficult to explain and predict precisely. In this article we review data on temperature variations in the past as well possible reasons for thesevariations. Subsequently, we review key properties of global climate models and statistical analyses conducted by others on the ability of the global climate models to track historical temperatures.

These tests show that standard climate models are rejected by time series data on global temperatures. Finally, we update and extend previous statistical analysis of temperature data
(Dagsvik et al., 2020). Using theoretical arguments and statistical tests we find, as in Dagsvik et al.(2020), that the effect of man-made CO2 emissions does not appear to be strong enough to cause systematic changes in the temperature fluctuations during the last 200 years.

Keywords: Global climate models, Climate change, Temperature analysis, Fractional Gaussian noise,
Long-range dependence

The Earth Is Mildly Warming, But Is CO2 The Cause?

by H.W. Jenkins, Nov 6, 2023 in ClimateChangeDispatch

If this column has ever plagiarized itself, it’s by repeating the phrase “evidence of warming is not evidence of what causes warming.”

A paper published by the Norwegian government’s statistical agency, written by two of its retired experts, touching on this very subject has called forth so many shrieked accusations of climate apostasy that you know it must be interesting.

The authors ask a simple question: Are computerized climate simulations a sufficient basis for attributing observed warming to human CO2? [emphasis, links added]

After all, the Earth’s climate has been subject to substantial warming and cooling trends for millenniathat remain unexplained and can’t be attributed to fossil fuels.

As statisticians, their conclusion: “With the current level of knowledge, it seems impossible to determine how much of the temperature increase is due to emissions of CO2.

Wow. For all the abuse dumped on them for this modest observation, and even some apologetic hemming and hawing from the government-run Statistics Norway, the authors don’t say climate models don’t make useful predictions.

Their predictions are useful precisely for testing the validity of climate models. What’s more, many concerned about climate change have no trouble seeing the problem as a matter of risks rather than certainties.

This includes coauthor John Dagsvik, who told Norway’s Aftenposten newspaper he favors emissions curbs for precautionary reasons.

The correlation-to-causation puzzle is hardly the authors’ invention, having bedeviled the oracular Intergovernmental Panel on Climate Change (IPCC) since its founding in 1988.

But unrestrained name-calling is required, the critics say, because anything that undermines confidence in climate models undermines progress against climate change.

New Study: ‘Atmospheric CO2 Is Not The Cause Of Climate Change’ … The Next Glaciation Has Begun

by K. Richard, Sep 28, 2023 in NoTricksZone

New research published in the MDPI journal atmosphere by Dr. Stuart A. Harris asserts past and modern climate changes are natural and not driven by variations in atmospheric CO2 concentrations.

Some key points from the paper include:

• Past and modern climate change is driven by solar cycle (Milankovitch) variations and their affect on ocean circulation and heat transport.

• Throughout the last hundreds of thousands of years, temperature changes precede the lagging changes in CO2.

• The UN IPCC position that atmospheric CO2 is the cause of the warming since the onset of the Industrial Revolution is only an assumption that is “not consistent with studies involving changes in temperature in rural areas of the northern [NH] hemisphere.”

• The natural 23 thousand year (23 ka) Milankovitch cycle has begun to reduce insolation in the NH “starting in 2020,” and this “heralds the start of the next glaciation.”

• CO2 is essential for life on Earth (photosynthesis), and a reduction in CO2 would be harmful to the biosphere. On the other hand, there “seems to be no connection between carbon dioxide and the temperature of the Earth.”

New Paper: Objective Measurements Show CO2’s Effect On Warming Not As Large As Modeled

by Dr R. Spencer, Sep 29, 2023 in ClimateChangeDispatch

A new research study from The University of Alabama in Huntsville, a part of the University of Alabama System, addresses a central question of climate change research: how much warming can be expected from adding carbon dioxide to the atmosphere through fossil fuel burning and other activities as standards of living increase around the world? [emphasis, links added]

UAH Earth System Science Center Research Scientist Dr. Roy Spencer and UAH Earth System Science Center Director and Alabama State Climatologist Dr. John R. Christy have spent 10 years developing a one-dimensional climate model to answer this elusive question.

Their latest research study was published in the September 2023 issue of Theoretical and Applied Climatologyjournal titled: “Effective climate sensitivity distributions from a 1D model of global ocean and land temperature trends, 1970–2021.”

Spencer and Christy’s climate model, based upon objective measured data, found carbon dioxide does not have as big of an effect on the warming of the atmosphere when compared with other climate models.

“For over 30 years, dozens of highly sophisticated, computerized climate models based upon theory have been unable to agree on an answer. That’s why we developed our own one-dimensional climate model to provide an answer,” says. Dr. Spencer.

Current climate models range over a factor of three, from 1.8 to 5.6° Celsius, in the amount of warming produced in response to a doubling of atmospheric carbon dioxide (CO2).

This warming response to doubled carbon dioxide is called “effective climate sensitivity.” Determining its magnitude has remained elusive for decades.

When compared to other current climate models, the research results from Spencer and Christy’s one-dimensional climate model approached the bottom end of the range, 1.9° Celsius.

The lower UAH value indicates that the climate impact of increasing carbon dioxide concentrations is much less [than] that based on other climate models.

An important assumption of our model, as well as the more complex models used by others, is that all climate change is human-caused,” Spencer states. “If recent warming is partly natural, it would further reduce climate sensitivity.”

What distinguishes this model developed at UAH from others is that it is driven by actual observations of warming, rather than theoretical assumptions about how the climate system responds to increasing greenhouse gases.

The one-dimensional climate model uses a variety of observational datasets of warming between 1970 and 2021 of the deep ocean and land, along with associated uncertainty ranges.

These datasets produced a range of estimates of climate sensitivity based on basic concepts of energy conservation.

“The 52-year period since 1970 is key. It represents the period of most rapid warming, with the highest confidence in the observational data of deep ocean warming,” Spencer states.

The results of Spencer and Christy’s research also showed a period of the most rapid growth in atmospheric carbon dioxide.

This is due to their climate model accounting for heat storage in deeper layers of land, which other climate models ignore.

A critical advantage of their simple model is that it conserves energy.

“It should be a requirement that any physics-based model of global warming should meet,” Spencer says. “Current computerized climate models continue to have difficulty achieving this aspect.

The model is simple enough that other scientists can easily adapt it to updated or improved global temperature measurements as they become available.

The Holocene CO2 Dilemma

by R. Hannon, June 2023, in WUWT

This post evaluates the relationship of global CO2 with regional temperature trends during the Holocene interglacial period. Ice core records show that CO2 is strongly coupled with local Antarctic temperature and slightly lags temperature over the past 800,000 years (Luthi, 2008). Whereas the emphasis has been on CO2 and temperature lags/leads, this study focuses on Holocene millennium trends in different latitude-bounded regions.

The Contrarian Antarctic

The Holocene is fortunate to have hundreds of proxy records analyzed by Marcott, 2013, and more recently Kaufman, 2020, to establish regional and global temperature trends. The Holocene interglacial occurs approximately during the past 11,000 years. In general, global temperature trends from proxy data show a Holocene Climatic Optimum (HCO) around 6000 to 8000 years ago and a subsequent cooling trend, the Neoglacial period, culminating in the Little Ice Age (LIA). The global mean temperature is comprised of regional trends that tend to have a concave down appearance during the Holocene shown in Figure 1a.

The exception is the Antarctic shown in red which has a concave up shape. The Antarctic reached an early Holocene Climatic Optimum between 9000 to 11000 years ago. While global and most regional temperatures were warming, Antarctic cooled to a minimum around 8000 years ago. While global and other regions show progressive cooling during the Neoglacial, the Antarctic was flat and erratic. This contrary Antarctic temperature behavior during the Holocene has also been noted by Andy May here.


Climate change is routinely claimed to be largely controlled by greenhouse gases, especially CO2. This was concluded, in part, by the strong relationship between CO2 from Antarctic ice core bubbles and local Antarctic temperature trends. While CO2 mimics Antarctic temperatures very well, ninety percent of Earth’s surface temperature trends do not demonstrate a positive correlation to CO2 during the Holocene. Arctic and Northern Hemisphere temperatures become cooler during increasing CO2 levels. Tropical proxy temperatures don’t seem to be influenced by CO2.

Model simulated temperatures which are strongly influenced by CO2 do not accurately history match Holocene global proxy temperatures and tend to largely reflect Antarctic trends. The fact that CO2 correlates well to Holocene temperatures for only the Antarctic, or <10% of our planet’s surface, yet CO2 is considered as the dominant influence on climate change is a scientific dilemma.

Download the bibliography here.

Study: Northern Greenland Was Ice Free, Forested ~125k Years Ago, Adding 3 Meters To Sea Levels

by Diamond et al. 2021, Apr 27, 2023 in NoTricksZone

During the last interglacial (LIG) 127 to 119k years ago, when CO2 levels were said to be only 275 ppm, Greenland’s Camp Century surface was ice free, vegetated. Today this same site is buried under a 1.4 kilometers-high ice sheet.

The Arctic was sea ice free during the LIG (Diamond et al., 2021).

More on Cloud Reduction. CO2 is innocent but Clouds are guilty.

by C. Blaisdell, 15 Apr 2023, in WUWT


This is a continuation of previous papers (1) and (2) on Cloud Reduction.  Further analysis of cloud data has revealed four new observations:

  1.  Mount Pinatubo ash in the atmosphere and Amazonia deforestation may be seen in the cloud data.
  2. A correlation of measured “Temperature – Dew point Temperature”, T-Td, to Cloud Cover was found.
  3. The Temperature – Dew point Temperature variable suggests Cloud Reduction has been going on before 1975.
  4. A simple model shows that Clouds either by reduced Cloud Fraction, decreased Cloud Albedo (lower reflectivity), or both can account for most of the observed Radiation and the associated Global Warming, GW.

CO2 is innocent but Clouds are guilty.


Climate change leaves a multi variable data finger print in the Atmosphere that is useful in drawing conclusions and testing theories.  The first of these finger prints is shown in Figure 1 where Cloud Cover, Temperature, Specific Humidity, and Relative Humidity (ground and 850mb) are shown on the same time scale.  None of Figure 1 graphs is a flat line any theory on GW should account for all these observations.  Figure 1 is NOAA data from “NOAA Physical Science Laboratory”, (3) average Northern and Southern Hemisphere.  In Figure 1 note that relative humidity at 1000mb is much less sensitive than the relative humidity at 850mb(where cumulus cloud are).  Cloud Data is from Climate Explorer, (11)

Another data finger-print data set is shown in Figure 2 from “Met Office Climate Dashboard” (“HadISDH” data), (4)  (station and buoy data).  Note that the Met Data has a much better relative humidity correlation.  The relative humidity is significant variable in the Dew Point temperature calculation, Figure 2 (e).

Scientists Say A 6°C Warmer-Than-Today Arctic Is ‘Optimal’ For Thermophile Species

by K. Richard, Apr 6, 2023 in NoTricksZone

Back in the Early Holocene, when CO2 levels were said to be ~255 ppm, Arctic Svalbard was warm enough to accommodate abundant numbers of thermophiles, or warmth-demanding species. Only “remnants” of these species and their habitat exist in today’s much-colder Arctic.

With the exception of a few centuries in recent millennia, today’s Svalbard (Arctic) is the most glaciated it has been in the last 10,000 years (see the blue trend line in the below chart from Brožová et al., 2023).


This region is today about 6°C colder than it was during the early Holocene (~10,000 to 8,000 years ago), a climatic period scientists characterize as an optimum, or “most favorable,” for a “rich species pool” of thermophiles.

The sea surface temperatures (SSTs) in the western Barents Sea were as warm as 13°C and “sea ice-free during most of the mid-Holocene” (Łącka et al., 2019). In contrast, today’s SST in this region are as cold as they were during the last glacial (2-4°C), when CO2 hovered near 200 ppm. Rapid double-digit SST fluctuations, varying from 3 to 13°C, have been ongoing throughout the Holocene.

Earth’s Greenhouse Effect Has Not Been Enhanced, But Instead Its Impact Has Declined Since 1983

by K. Richard, April 10, 2023 in NoTricksZone

In the satellite era scientists have continued to observe the Earth’s total greenhouse effect (which includes effects from greenhouse gases and clouds) exerting an overall negative impact (cooling) on surface temperatures since the 1980s. This rules out both CO2 and an enhanced greenhouse effect as drivers of global warming.

Earth’s total greenhouse effect impact on climate is realized by the sum of all contributors to it: water vapor, clouds, and the “anthropogenic” greenhouse gases CO2 and CH4.

Given the modern assumption that humans are responsible for global warming due especially to our CO2 and CH4 emissions, it stands to reason that Earth’s downwelling longwave (LWdn) should be increasing and thus the Earth’s greenhouse effect should be enhanced due to the rising greenhouse gases emissions.

But, as Cess and Udelhofen (2003) reported 20 years ago, Earth’s greenhouse effect has not been enhanced in recent decades. Instead, it has been in a state of decline since the 1980s.

“[T]he negative trend in G [greenhouse effect] indicates that the atmospheric greenhouse effect is temporarily [1985-1999] decreasing despite the fact that greenhouse gasses are increasing.”

Real-World Observation: Increasing CO2 By 7,000 ppm Has A 0.3°C Temperature Differential

by K. Richard, Mar 30, 2023 in NoTricksZone

Surface air CO2 concentrations vary by 100s to 1,000s of ppm within a span of hours to days or weeks across the natural world. The observational evidence suggests these variations are neither driving or even causing temperature changes.

According to recent field research (Mungai, 2021) conducted in Kenya, the observed CO2 concentrations in the atmospheric air above mofette springs (8) averages 3,400-4,800 ppm. Interestingly, the temperatures associated with these high CO2 levels are “relatively low” or “cold” (~21.5 to 29.5°C) compared to ambient temperatures at other nearby sites with ~400 ppm CO2.
The study also shows that when CO2 increases from 5,253 ppm in wet season to 12,138 ppm in dry season over a mofette springs site, there is only a 0.3°C temperature differential (23.4°C vs. 23.1°C) associated with this >7,000 ppm CO2 change. The sensitivity of the surface air temperature to these extremely high CO2 variations would appear to be vanishingly small – or non-existent.

New Study: Atmospheric CO2 Residence Time Is Only 5 Years – Too Short To ‘Affect The Climate’

by P. Stallinga, Mar 23, 2023 in NoTricksZone

Since the early 1990s the conventional assumption, aligned with modeling, has been that a molecule of human CO2 emission stays in the atmosphere –  its residence time – for centuries. This fits the anthropogenic global warming (AGW) narrative. But empirical evidence contradicts these model-based assumptions. Residence time is closer to 5-10 years.

In Table 1 of a new study, Stallinga (2023) compiled a list of 36 published estimates of CO2 residence time spanning the decades 1957-1992. All of these scientists determined CO2’s atmospheric residence time is about 5 to 10 years or less.

Of course, these were the pre-IPCC decades in climate research, when “the science” was pursued independent of government interference. For example, it was still acceptable in the 1950s to early 1990s for scientists to publish actual ice core measurements showing the atmospheric CO2 content ranged up to 700 ppm, even 2,450 ppm, in the ice sheets and glaciers examined throughout the last 10,000 years (Jaworowski et al., 1992).

An actual residence time that is 20 to 40 times shorter in duration than what an AGW modeled thought experiments allow undermines the dangerous greenhouse gas accumulation talking points, as “if the residence time is below 30 years, injections of CO2 in the atmosphere would, just as water, not affect the climate” (Stallinga, 2023).

In addition to compiling an exhaustive list of past estimates supporting a 5-10 year residence time, Dr. Stallinga cites the evidence from atomic bomb tests, the lack of any atmospheric CO2 effect from the pandemic lockdowns and associated sharp drop in  emissions, and the lead-lag relationship CO2 emission has with temperature as evidence supporting the once commonly-accepted conclusion that CO2 residence is closer to 5 years, not centuries.

The Global Warming Doomsday Religion Is A Suicide Pact To Wreck Our Economy

by D.W. Crockett, Mar 14, 2023 in ClimateChangeDispatch

There is no scientific evidence that the minuscule 0.01% increase in atmospheric carbon dioxide (CO2) since 1780 has had any effect on the Earth’s average temperature.

Nonetheless, in the 1980s, a religious/political movement against man-made or anthropogenic CO2 arose.

It was driven by catastrophic predictions from a gaggle of impenetrable and undecipherable computer climate models operated by the International Panel on Climate Change (IPCC) and quickly metastasized into a worldwide mass movement with all the fervor of a new evangelical religion.

As Eric Hoffer observes in his book, The True Believer, “Mass movements can rise and spread without belief in God, but never without belief in a devil.”

In this new “doomsday” mass movement, millions of people truly believe that man-made CO2 is a modern-day devil that will cause glaciers to melt, seas to rise, and coastlines to submerge. They also believe that mankind can, and must, save the planet from this catastrophe by reducing emissions of the devil CO2 to net zero.

Those who don’t believe are labeled “climate deniers,” a derogatory reference to those who deny that the Nazis perpetrated the Holocaust.

Unfortunately, most politicians in the U.S., Canada, and Europe, as well as the press and heads of many large corporations have blindly joined this Anthropogenic Global Warming (AGW) religion to stamp out the CO2 devil.



The test that exonerates CO2

by J. Vinos, Feb 26, 2023

Most people don’t have a clear understanding of the greenhouse effect (GHE). It is not complicated to understand, but it is usually not well explained. It is often described as “heat-trapping,” but that is incorrect. Greenhouse gases (GHG) do not trap heat, even if more heat resides within the climate system due to their presence in the atmosphere. The truth is that after adjusting to a change in GHG levels, the planet still returns all the energy it receives from the Sun. Otherwise, it would continue warming indefinitely. So, there is no change in the energy returned. How do GHGs produce GHE?

GHGs cause the atmosphere to be more opaque to infrared radiation. As solar radiation heats mainly the ocean and land surface of the planet, GHGs absorb thermal emission from the surface at the lower troposphere and immediately pass that energy along to other molecules (typically N2 and O2) through collisions that occur much faster than the time it would take to re-emit the radiation. This warms the lower troposphere. The density and temperature decrease rapidly through the troposphere, so molecules are colder and more separated at the upper troposphere. Now GHGs have a chance to emit IR radiation so when they finally collide with another molecule, they are colder so GHGs have a cooling effect in the upper troposphere and stratosphere.

Because GHGs make the atmosphere more opaque to IR radiation, when they are present the emission to space from the planet normally does not take place from the surface (as happens in the Moon). Part of it still takes place from the surface through the atmospheric window, but most of it takes place from higher in the atmosphere. We can define a theoretical effective emission height as the average height at which the Earth’s outgoing longwave radiation (OLR) is being emitted. The temperature at which the Earth emits is the temperature at the effective emission height in the atmosphere. That temperature, when measured from space is 250 K (-23°C), not 255 which is the calculated temperature for a theoretical blackbody Earth. That temperature corresponds to a height of about 5 km, which we call the effective emission height.

Microbes that co-operate contribute more carbon emissions

by Imperial College London, Feb 13, 2023 in ScienceDaily

Despite being small, microbes, and especially bacteria, contribute a lot to the global carbon cycle — the movement of carbon in various forms through nature. Its level in the atmosphere, and so its influence on climate change, is controlled by a series of sources and sinks, such as respiration and photosynthesis respectively.

Now, new research from Imperial College London and University of Exeter scientists has shown that, when warmed, bacterial communities that have matured to co-operate release more carbon dioxide (CO2) than communities that are in competition with each other.

The results are published in Nature Microbiology.

Co-author Dr Tom Clegg, who led the theory development from the Department of Life Sciences (Silwood Park) at Imperial, said: “Our findings have far-reaching implications given the significant contributions that bacterial communities make to the carbon cycle. We show that changes in bacterial species interactions can rapidly and substantially increase the carbon emissions from natural ecosystems worldwide.”

Bacteria — like humans — respire, taking in oxygen and releasing CO2. Of the many factors that control their level of respiration, temperature is particularly important.

Bacteria form communities of different species in all habitable environments, including in soil, puddles, and in our guts. When communities first form, the bacterial species are often ‘competitive’, each trying to get the best resources.

Forest-Limit (Betula pubescens ssp. czerepanovii) Performance in the Context of Gentle Modern Climate Warming

by Kullman, Feb 6, 2023 in NoTricksZone

Claims the Swedish Scandes are unprecedentedly warm and tree-covered today “appear as large and unfounded exaggerations,” as the “climate and arboreal responses” of the last few decades “are still inside the frames of natural historical variation.” – Kullman, 2022 and Kullman, 2022a

Extensive birch forest fossils can be dated to the early- to mid-Holocene in northern Scandinavian regions, indicating these warmth-sensitive trees could exist in climates that are too cold for them to grow in today. This documents a much warmer period, “at least 3°C higher than during the past few decades,” 3000 to 10,000 years ago, or when CO2 was about 265 ppm (Kullman, 2022).

Contrary to modeler opinions, “there is little factual nourishment” to support modern projections that the Swedish Scandes will soon be returning to the subalpine birch forest climates of past millennia. The observed forest advancement in recent decades “is so small” that these modeling claims appear to be “unfounded exaggerations.”

Kullman, 2022

“In the southernmost Swedish Scandes, pine has already “leap-frogged” over receding the birch forest-limit (Kullman 2014, 2019). That scenario would mimic the arboreal landscape during the early Holocene and shift to a landscape unseen for thousands of years (cf. Blűthgen 1942; MacDonald et al. 2008, Macias-Fauria et al. 2012). During that epoch, summer temperatures are inferred to have been at least 3°C higher than during the past few decades.”
“At the landscape level, the obtained changes contribute to a greater and lusher landscape, in contrast to the dire conditions during the Little Ice Age, more than 100 years ago (Kullman 2010, 2015). Currently, there is little factual nourishment to flourishing projections stating that a major part of Swedish alpine areas is on verge of transformation to subalpine birch forest (e.g. Moen et al. 2004). Apparently, climate and arboreal responses are still inside the frames of natural historical variation, as inferred by several authors (e,g. Hammarlund et al. 2004; Bergman et al. 2005; Kullman 2013, 2017a, b; Kullman & Öberg 2018, 2020).”
“Given that the current relatively warm climate phase continues, the subalpine birch forest belt may eventually recede and give way to a subalpine pine belt. The obtained modest forest-limit advancement is so small that flourishing model simulations of extensive birch forest expansion over most of the current alpine tundra appear as large and unfounded exaggerations.”

Tree remnants (trunks, cones, roots, etc.) found at northern Sweden mountain sites 500 to 700 meters atop where the 21st century tree line ends imply the early-Holocene (~13,000 to 7000 years ago) climate was significantly warmer than today in this region (Kullman, 2022a).

The temperature lapse rate for the Swedish Lapland region is 0.6°C/100 m. Accounting for glacio-isostatic uplift, this tree line elevation implies surface air temperatures were 3.6°C higher than today during the Early Holocene.

Kullman, 2022a


In Search Of A (Near) Perfect CO2 Global Warming Analogy

by R. Barmby, Jan 23; 2023 in ClimateChangeDispatch

Most people have a firm opinion on whether human emissions of carbon dioxide (CO2) are causing unnatural global warming, and hold that opinion without understanding how the molecule physically absorbs and then releases heat energy.

Understanding that mechanism reveals why today’s significant global CO2 emissions are insignificant to future global warming.

Analogies are a great way to explain science, and I’m going to share the worst and best analogies for how carbon dioxide acts as a greenhouse gas. I will also share why the warming effect of CO2 is limited.

Why Today’s Carbon Dioxide Emissions Are Insignificant To Global Warming

As more CO2 molecules are added as potential absorbers for the fixed amount of the specific band of infrared radiation, there is less chance that any CO2 molecule will be hit. If the additional CO2 molecules do not absorb infrared radiation, they cannot contribute to global warming.

The ever-reducing CO2 contribution to global warming looks like this graph, which, ironically, is based on the IPCC’s formula (from Inconvenient Facts by Gregory Wrightstone):

On the graph above, consider that the pre-industrial (circa 1875) atmospheric CO2 level was about 280 parts per million (ppm), and today it is about 420 ppm—an increase of 140 ppm.

As a rough approximation, the three bars labeled 350, 400, and 450 ppm represent this past increase in CO2, and the sum of the global warming temperature increases associated with those three bars is about 0.7°C.

The next four bars (500, 550, 600, and 650 ppm) represent a future CO2 increase of 200 ppm, which at today’s rate of 2.5 ppm increase each year would take from now to about 2100.

The global warming associated with those four bars is only 0.65°C. The graph shows it keeps taking more CO2 to achieve a smaller amount of global warming.

I chose bars 350 through 650 ppm to highlight that the IPCC’s formula predicts that global warming from current CO2 emissions held flat (1.35°C) would still beat the IPCC’s target of 1.5°C of human-caused global warming from preindustrial times to the year 2100.

The above graph suggests global warming from increasing CO2 never stops, but we know from ancient climates that even 12 times today’s CO2 concentrations did not cause runaway global warming.

Drs. Happer, Koonin, and Lindzen submitted to the U.S. (Northern California) District Court in 2021 that minor changes in cloud cover and convection currents can have a bigger effect on the Earth’s surface temperature than major increases in CO2.

Mauna Loa Observatory

by Climate Auditor, January 2023

Atmospheric CO2 concentration

Here in Figure 1 is the monthly atmospheric CO2 concentration measured at the Mauna Loa Observatory, Hawaii, Latitude19.5̊ N, Longitude 155̊ W, elevation 3397m, for the 64 year period from March 1958 to May 2022.

Figure 1. Monthly atmospheric CO2 concentration, Mauna Loa Observatory, Source:[ Ref. 2]

The source file, Ref. 2, lists the data in 10 columns. The columns used here were columns 3 and 4, the date in Excel and decimal format, column 9 being the measured CO2 concentration with missing values in-filled from a smoothed fit to the data and column 10 being the seasonally adjusted measurements again with missing values in-filled.

The monthly CO2 concentration had an average rate of increase over the 64 year period from March 1958 to May 2022 of 1.60 ppm pa. For the 5 year period March 1958 to March 1963 the rate was 0.68 ppm pa and for the 5 year period May 2017 to May 2022 the rate was 2.50 ppm pa, that is, the rate of increase has steadily accelerated over time to be 3.7 times greater than it was 59 years earlier. The range was from a minimum of 312.43 ppm to a maximum of 420.78 ppm.

The amplitude of the seasonal variation was estimated to range from 5.25 ppm to 8.03 ppm, increasing in amplitude over time, in an irregular fashion. The maxima occurred, on average, in early May, which is the beginning of Summer, and the minima in late September, at the end of Summer. The greatest seasonal variation took place between September 2015 and April 2016. This means that the CO2 concentration rose during the cool of Winter and fell during the heat of Summer, which is out of phase with the UN IPCC claim that increased CO2 concentration causes an increase in temperature. Nor does the UN IPCC hypothesis provide an explanation for the steady increase in the rate of increase of the CO2 concentration.

Temperature and CO2 concentration

Here is 522 months of empirical data, showing a distinct lack of a relationship between the Tropics satellite lower troposphere temperature [ Ref.1] and the seasonally adjusted atmospheric CO2 concentration at the Mauna Loa Observatory.


Figure 2. Mauna Loa Observatory, Source: [ Ref. 1] and [ Ref. 2]

Figure 2 shows the monthly satellite lower troposphere temperature for the Tropics zone, 20̊ South to 20̊ North, in blue, and the relevant monthly CO2 concentration in red after removal of the seasonal variation so as to match the residual temperature series. The range for the monthly CO2 concentration is from 335.77 ppm to 418.2 ppm. The range for the Tropics temperature is from -0.99̊ Celsius to +1.15̊ Celsius with respect to a 30 year average base value. The clear and obvious difference between the two raises the possibility that there may be no common causal factor whereby the CO2 concentration drives the temperature as claimed by the UN IPCC.

Calculation of the Ordinary Linear Regression between the two time series gave a Pearson correlation coefficient of 0.462 from the 522 monthly data pairs. This is a measure of the relationship between the background linear trend of each of the time series as shown by an almost identical correlation of 0.463 between the temperature and the time. The correlation between the CO2 concentration and the time was 0.995, that is, the seasonal adjusted CO2 concentration time series was practically a linear trend with respect to time. Any pair of linear trends, no matter what their source, will have a high correlation coefficient of about 1.0 which is necessarily of no causal significance as a background linear trend with respect to time can be calculated for any time series.

New Study: A ‘Thought Model’ Saying There’s A 33 K ‘Natural Greenhouse Effect’ Is ‘Meritless’ Assumption

by K. Richard, Dec 26, 2022 in NoTricksZone

The conceptualization of a 33 K warmer Earth due to the presence of water vapor and CO2 (greenhouse gases) in the atmosphere is wholly based on the unobserved and unknown, or assumptions about what an imaginary world with no atmosphere would be like.

It is widely believed that we can determine the effective radiating temperature, a uniformly global temperature, the globally uniform albedo…of a rocky planets simply by conjuring up thought experiments about what a made-up world would be like if it did not have an atmosphere (e.g., no N2, O2, atmospheric pressure, clouds, water vapor…).

This “thought model” has been subjected to critical analysis in a new paperpublished by four atmospheric physicists.


Image Source: Kramm et al., 2022

The authors use observational measurements from 24 datasets for the moon — which actually is the closest real-world proximity to a rocky planet without an atmosphere — as their testbed. They conclude that the globally averaged surface temperature is necessarily “about 60 K” lower than the effective radiation temperature, rendering the “thought model” presumptions about a 33 K “greenhouse effect” differential for the effective radiating vs. global average temperature (255 vs. 288 K) “meritless.”

Other instances of a disqualifying contrast between observations and modeled assumptions include:

What If Real-World Physics Do Not Support The Claim Top-Of-Atmosphere CO2 Forcing Exists?

by K. Richard, Dec 22, 2022 in NoTricksZone

 Schneider et al., 2020, NASA, UCAR, CGA

TOA greenhouse gas forcing is a fundamental tenet of the CO2-drives-climate-change belief system. And yet the “global-mean longwave radiative forcing of CO2 at TOA” (Schneider et al., 2020) may not even exist.

It is easily recognized that water vapor (greenhouse gas) forcing cannot occur above a certain temperature threshold because water freezes out the farther away from the surface’s warmth H2O goes.

According to NASA, the TOA is recognized as approximately 100 km above the surface. The temperature near that atmospheric height is about -90°C.

CO2 is in its solid (dry ice) form at -78°C and below.

Therefore, TOA CO2 radiative forcing cannot exist if CO2 cannot be a greenhouse gas at the TOA.

New Study: Observational Data Affirm 95% Of Post-1970s Warming Is Not Linked To CO2 Increases

by K. Richard, Dec 8, 2022 in NoTricksZone

Of the warming trends in Poland and greater Europe, “only about 4–5% are explained by an increase in CO2 concentration.”  –  Marsz et al., 2022 

Internal changes to the thermal structure of the ocean transmit decadal-scale changes in the atmospheric circulation and consequent surface air temperature via its modulating impact on the variation in the amount and intensity of solar radiation (sunshine duration, or SD) reaching the Earth’s surface.

This is not only observed for Poland and/or Europe as detailed in a new study, but the causal structuring of cloud cover changes driving the variations in solar radiation reaching the surface and modulating climate can be applied throughout the globe ( Wang et al., 2002, Wielicki et al., 2002Loeb et al., 2021, Herman et al., 2013Poprovsky, 2019, Dübal and Vahrenholt, 2021, Swift, 2018, Stephens et al., 2022).

Therefore, “the main cause of the change in the state of the climate may be the action of the internal variability of the ocean–atmosphere system” (Marsz et al., 2022).

Study Finds The CO2 Greenhouse Effect Is Real…But Dangerous Global Warming From Rising CO2 Is Not

by K. Richard, Nov 24, 2022 in NoTricksZone

German physicists claim to have experimentally demonstrated the greenhouse effect from greenhouse gases like CO2 and CH4 is a real phenomenon, but assess the climate sensitivity to a doubling of CO2 with feedbacks is “only ECS = 0.7°C … 5.4x lower than the mean value of CMIP6 with ECS = 3.78°C.”

“The derived forcing for CO2 is in quite good agreement with some theoretical studies in the literature, which to some degree is the result of calibrating the set-up to the spectral calculations, but independently it determines and also reproduces the whole progression as a function of the gas concentration. From this we deduce a basic equilibrium climate sensitivity (without feedbacks) of ECSB = 1.05°C. When additionally assuming a reduced wing absorption of the spectral lines due to a finite collision time of the molecules this further reduces the ECSB by 10% and, thus, is 20% smaller than recommended by CMIP6 with 1.22°C.”
“Detailed own investigations also show that in contrast to the assumptions of the IPCC water vapor only contributes to a marginal positive feedback and evaporation at the earth’s surface even leads to a significant further reduction of the climate sensitivity to only ECS = 0.7°C (Harde 2017 [15]). This is less than a quarter of the IPCC’s last specification with 3°C (see AR6 [1]) and even 5.4x lower than the mean value of CMIP6 with ECS = 3.78°C.”


by F. Engelbeen, Nov 2022

In climate skeptics circles, there is rather much confusion about historical/present CO2 measurements. This is in part based on the fact that rather accurate historical direct measurements of CO2 in the atmosphere by chemical methods show much higher values in certain periods of time (especially around 1942), than the around 280 ppmv which is measured in Antarctic ice cores. 
280 +/- 10 ppmv is assumed to be the pre-industrial amount of CO2 in the atmosphere during the current interglacial (the Holocene) by the scientific community. This is quite important, as if there were (much) higher levels of CO2 in the recent past, that may indicate that current CO2 levels are not from the use of fossil fuels, but a natural fluctuation and hence its influence on temperature is subject to (huge) natural fluctuations too and the current warmer climate is not caused by the use of fossil fuels.

To be sure about my skepticism: I like to see and examine the arguments of both sides of the fence, and I make up my own mind, based on these arguments. I am pretty sure that current climate models underestimate the role of the sun and other natural variations like ocean oscillations on climate and overestimate the role of greenhouse gases and aerosols. But I am as sure that the increase of CO2 in the atmosphere since the start of the industrial revolution is mainly from the use of fossil fuels.

There are several reasons why the hypothesis of large non-human CO2 variations in recent history is wrong (see my comment on the late Ernst Beck’s compilation of historical measurements) and that most of the recent increase in CO2 in the atmosphere indeed is mainly man-made, but that needs a step-by-step explanation. Follow the steps: 

  1. Evidence of human influence on the increase of CO2 in the atmosphere.

    1. The mass balance
    2. The process characteristics
    3. The 13C/12C ratio
    4. The 14C/12C ratio
    5. The oxygen use
    6. The Ocean’s pH and pCO2
    7. The processes involved
  2. Conclusion

  3. Extra: how much human CO2 is in the atmosphere?

  4. Reference


Mid-Pleistocene transition in glacial cycles explained by declining CO2 and regolith removal

by Willeit et al., 2019 in ScienceAdvances


Variations in Earth’s orbit pace the glacial-interglacial cycles of the Quaternary, but the mechanisms that transform regional and seasonal variations in solar insolation into glacial-interglacial cycles are still elusive. Here, we present transient simulations of coevolution of climate, ice sheets, and carbon cycle over the past 3 million years. We show that a gradual lowering of atmospheric CO2 and regolith removal are essential to reproduce the evolution of climate variability over the Quaternary. The long-term CO2 decrease leads to the initiation of Northern Hemisphere glaciation and an increase in the amplitude of glacial-interglacial variations, while the combined effect of CO2 decline and regolith removal controls the timing of the transition from a 41,000- to 100,000-year world. Our results suggest that the current CO2 concentration is unprecedented over the past 3 million years ant that global temperature never exceeded the preindustrial value by more than 2°C during the Quaternary.

Another Study Says Europe Was At Times Warmer During The Last Glacial When CO2 Levels Were 40% Lower

by K. Richard, Oct 24, 2022 in NoTricksZone

The Earth was still in ice age conditions 14,700 to 12,900 years ago, or during the “Bolling interstadial.” CO2 hovered near 230 ppm at that time, and yet “continental Europe was a few degrees warmer than present” (Toth et al., 2022).

In recent years there have been multiple studies detailing a European climate that was as warm or warmer than today during the late Pleistocene ice age.

The latest study, Toth et al., 2022, uses chironomid proxy evidence to reconstruct summer temperatures at a lake site in the Eastern Carpathians.

These authors report that “continental Europe was a few degrees warmer than present during the Bolling interstadial,” and there were slightly (0.5°C) warmer-than-today periods (e.g., ~16,300 years ago) at the study site. The warming events were both pronounced (5°C) and abrupt.

LA Times reveals 2020 CA Wildfire CO2 Wiped Out 18 Years of the State’s Emissions Reductions

by L. Hamlin, Oct 22, 2022 in WUWT

The article notes that “researchers estimated that about 127 million metric tons of carbon dioxide equivalent were released by the fires, compared with about 65 million metric tons of reductions achieved in the previous 18 years.”

The Times article provided the usual climate alarmist hype that “climate change” is responsible for the California’s increased wildfire damage noting:

“Forests have long played a role in that system, with large trees sequestering carbon and helping to alleviate some emissions. But California’s new breed of climate-change-fueled fires are burning hotter and faster than those of the past, sometimes slowing the regrowth process and even converting some areas from coniferous trees into grasslands, shrubs and chaparral, the researchers said.”

However a 2021 prior WUWT article addressed the fact that year 2020 wildfire emissions likely wiped out the state AB 32 emissions reductions and also addressed in detail the huge state government forest management failures that have contributed to the states wildfire growth and increasing risks over the past decade with these critical failures hidden from view in the Times article.  This prior WUWT article notes:

“California’s climate alarmists claim “climate change” is responsible for this wildfire outcome but an extensive 2018 California Legislative Analyst Office (LAO) report presents clear and compelling evidence demonstrating that decades of forest mismanagement by the state have in fact created the growing wildfire crisis.

The LAO report notes that increased fire risks are present throughout California driven by forest conditions that have been allowed by the state to develop for decades.”

Provided below are some of the highlights (or lowlights) of the state governments forest management failures that have led directly to increased wildfire growth and risks that have nothing to do with “climate change” as addressed in the states LAO analysis and presented in the prior WUWT article.