German Physicist: Human CO2 Emissions Responsible For 0.05°C Of The Global Warming Since 1750

Professor Herman Harde, an environmental physicist, has authored a new position paper on the follies of assuming humans significantly impact the climate.

As detailed in his 2017 paper, Dr. Harde concludes the “anthropogenic contribution to the actual CO2 concentration is found to be 4.3% [a figure derived from IPCC AR5], its fraction to the CO2 increase over the Industrial Era is 15% and the average residence time 4 years.”

The IPCC overestimates the thermal effect of doubling CO2 by a factor of 5, as the consequent surface air temperature increase for a 120 ppm increase in CO2 is less than 0.3°C.

“Since only about 15% of the global CO2 increase is of anthropogenic origin, just 15% of 0.3°C, i.e., less than 0.05°C remains, which can be attributed to humans in the overall balance.”

“Changes of our climate can be traced back to natural interaction processes that exceed our human influence by orders of magnitude.”

Image Source: Harde, 2022

34 responses to “German Physicist: Human CO2 Emissions Responsible For 0.05°C Of The Global Warming Since 1750”

  1. Richard Greene

    The right answer is no one knows.
    This so called professor is wild guessing.
    His “study” is a waste of bandwidth and/or paper.

    1. Senex

      If the right answer is “No one knows”, aren’t existing climate change policies also based on wild guessing?

      1. Richard Greene

        Exactly right !
        Always wrong wild guesses of the future climate.
        That’s what “climate change”: has become.
        Predictions, not climate reality.
        Increasingly hysterical predictions of doom.

        We don’t know how much warming since the 1770s
        was man made. Or since 1975.
        We do know that warming was good news.
        We don’t know how much warming is ahead.
        We don’t even know whether the climate will
        be warmer or colder in 100 years.

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  3. Richard Richard

    I think Harde’s linear technique is simplistic, but it’s much more realistic than the IPCC, which I assume was the point of the post.


  4. Robert Folkerts

    Kenneth, are you really qualified to speak on behalf of all others?
    Does sound somewhat arrogant.

  5. John Hultquist

    Richard Greene says, “no one knows.”

    In a sane world trillions would not be spent on an issue where “no one knows” is the right answer.

    However, I vote for “no climate emergency.”

    1. Richard Greene

      Although climate reconstructions are rough estimates of local climates in the past, based on them I believe the current climate is the best climate for humans, animals and especially plants, since the Holocene Climate Optimum from 5000 to 9000 years ago. We should be CELEBRATING the current climate !

      The “climate emergency” has been “coming” in 10 to 20 years for at least the past 50 years … and will probably be “coming” in 10 or 20 years for the next 50 years. The imaginary coming climate crisis just never shows up.

  6. Brian Gregory

    This paper: (,_Its_14C_Specific_Activity,.2.aspx) tends to support Harde’s reasoning; suggesting that no more than 12% (i.e., 120ppmv is of natural origin. Hardly surprising, when over 95% of annual global CO2 emissions are from natural sources that humanity has no means of controlling.

    1. Richard Greene

      “Hardly surprising, when over 95% of annual global CO2 emissions are from natural sources that humanity has no means of controlling.”
      All of +100 ppm increase of atmospheric CO2 can be explained by
      CO2 emissions from burning fossil fuels.
      There is no other explanation.

      There is no “natural increase” in the amount of CO2 in the atmosphere. Nature is removing CO2 from the atmosphere, each year, not adding it. Mankind has added about 180% of the measured increase in the amount of CO2 in the atmosphere since 1959.

      We know from reliable measurements that every year since 1959 the amount of CO2 in the atmosphere has increased by less than the amount of CO2 which mankind has added to the atmosphere (with the arguable exception of 1973, a year in which the two numbers were very similar).

      Mankind increases the CO2 concentration in the atmosphere, and nature reduces it (since 1959, at least). That means the only reason that the atmospheric CO2 level continues to rise is that mankind is adding CO2 faster than nature is removing it.

      1. Yonason

        “I reject the claims in this article of a scientist
        who claimis to know the exact effect of CO2 since 1750.” – R.G.

        That from the person who asserts, w/o any evidence, that…

        “All of +100 ppm increase of atmospheric CO2 can be explained by
        CO2 emissions from burning fossil fuels.”

        Seriously, R.G.? Well, I guess Murry Salby is right – “…it’s a subject upon which nearly everyone has an opinion.”
        No doubt you think he’s wrong, as well?

        You are even more closed minded than you falsely accuse Dr Harde of being.

        ALSO – I repeat: as i read Dr Harde’s first paper, he is claiming that if temperatures and the effect on them are as the IPCC asserts, the IPCC can’t be correct. His analysis, as i wrote above, is more rigorous and more in line with reality than the IPCC’s, which in turn is more careful than yours (which doesn’t say much for yours).

        ALSO – Your answer to Senex is incorrect, because even if the IPCC was correct about CO2 and it’s effects on temperature, the response to that would still be wrong in spite of their being right about the problem, which they are not. So the IPCC being wrong about human effects on temperatures and climate is not what makes their recommended response wrong. It’s just wrong.

  7. Tom Anderson

    One observation about any conclusion of how much CO2 warms or warms over time is that it possibly does not warm at all. That was Freeman Dyson’s opinion and I have seen it elsewhere. Warming seems to be an embedded assumption never questioned but critical to the discussion. On investigation, radiant activity by any element or molecule is at spectral bands of radiation determined by its quantum number or multiple thereof, by which it radiates at different temperatures. Einstein and Planck noted this.
    Carbon dioxide has been shown to radiate overwhelmingly (99.83% in one experiment) at the 15-micron wavelength, which by Wien’s Displacement law is about 193K or 80°C. Some physicists seem to know this, but the information isn’t very widespread.

    In satellite images you can see the large missing wedge of outgoing terrestrial radiation at the 15μm wavelength, where higher-altitude CO2 has absorbed and radiated away that band of incoming solar radiation (at 80°C). Lightfoot & Mamer noted CO2’s interaction at that wavelength in the Antarctic plateau during the southern winter. The ratio of water vapor to CO2 is 1:1 at the poles.
    The next larger radiant band is at 9.6 microns which many agree goes direct through the atmospheric window to space with other 8-12μm radiation. Dr. Salby says that it goes to warm the ozone layer with other -12 μm emissions through the window to space. The searingly hot CO2 bands 1100-800°C are apparently only one photon per ~158 million molecules.

    Remember, too that CO2 from burning fossil fuels is significantly offset by aerosols, smoke and soot, which screen out sunlight and reflect solar energy back to space. Rasool & Schneider (1971) advised against using them to hold off the 1970s “ice age threat” because fossil fuels were coolants. Probably still are.

    1. Petit_Barde

      I wish to point out that according to Wien’s deplacement law, 15µm wavelength corresponds to a body’s temperature of -80°C (minus 80°C).

      With respect to the Antartic, indeed, the spectral analysis shows an increase in radiation rather than a decrease, in the CO2 emission band around 15µm.

      See for instance Wijngaarden and Happer 2020 (see f- Antarctica observations) :


    2. Ferdinand Engelbeen


      Gases don’t follow the same rules of energy emissions and absorption as solid and liquid materials.
      Wien’s depacement law doesn’t apply to gases, as that are not black or grey bodies, they are nobodies like for N2 or O2, which don’t intercept or emit anything in the IR band, or they are intercepting and emitting in very molecular specific wavelengths like water vapor, CO2, CH4,…

      The emission and absorption bands by CO2 are (near) completely independent of its own temperature or of the surrounding gases. It is only a package of energy at very specific wavelengths that is absorbed and emitted, whatever its own temperature or that of the sender.

      Reason why a CO2 laser at maximum 100°C with a beam of around 10 micron can melt steel at 1200°C:

      The probably best explanation why gases are not black/grey bodies, as I have found:


    […] Fonte : NoTricksZone […]

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  10. E. Schaffer

    It is all there in hitran and modtran, if they are correct. It does not even take a lot of research to find out. The problem is they can easily be misunderstood. And Harde is no (positive) exception there.

    How much radiation GHGs absorb is irrelevant. What matters is by how much they reduce emissions TOA. Also you can not simply model “66% clouds”. Clouds have different optical depths and if you assume 66% opaque cloud cover, you nuke the fridge. Also cloud altitude is pivotal.

    It is regrettable he made all these mistakes on assessing climate sensitivity, when avoiding them would have yielded not a much different outcome. Because indeed overlaps make all the difference. 3.7W/m2 CO2 forcing and 1.8W/m2 in WV feedback are theoretical figures EXCLUDING any overlaps.

    If you allow for overlaps (and realistic surface emissions), you only get about 2W/m2 for 2xCO2, and merely 0.65W/m2 for WV feedback. Clouds have much larger overlaps with WV than with CO2 btw. since the emission altitude of CO2 is higher.

  11. Richard Greene

    CO2 and other greenhouse gases
    interfere with earth’s ability to cool itself.
    That is described as “warming”,
    which can be confusing.

    The actual pollution (not the CO2)
    from burning fossil fuels without
    modern pollution controls is a problem.
    Air pollution can be severe over
    environmental problem.

    There is no doubt that air pollution
    can block some sunlight.
    Air pollution was the original excuse
    for why there was significant
    global cooling from 1940 to 1975
    as CO2 levels rose.

    That excuse fell apart like a cheap suitcase in 1975.
    With very little change in the air pollution
    (which was not significantly reduced until 2000),
    the 1940 to 1975 global cooling trend ended,
    and a global warming trend began in 1975.
    The air pollution did not suddenly fall out
    of the sky in 1975, allowing global warming to begin.

    So we had a contradiction:
    Air pollution allegedly caused global cooling
    from 1940 to 1975, but air pollution also caused
    global warming after 1975 ??
    That made no sense.
    The “solution” to that contradiction:
    The global cooling from 1940 to 1975 was
    “revised away” — that inconvenient cooling
    trend never happened, we are now told.

    Never forget that historical
    global average temperature numbers
    are whatever government bureaucrats
    tell you they are.
    And those bureaucrats are biased
    to show more warming. Remember that
    they have predicted rapid, dangerous
    global warming since the 1970s.
    And they want their predictions
    to look good.

  12. Ross McLeod

    The laws relating radiation and temperature come from the 19th Century cavity oven experiments and relate to a continuous emission spectrum observed.

    No gas emits a continuous emission spectrum and using the blackbody radiation laws in postulating any sort of warming attributable to doubling of CO2 concentrations is totally unsubstantiated scientific gobbledygook.

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  14. Ferdinand Engelbeen

    Sorry, a little late in this discussion, of which I heard only recently…

    I have reacted on Harde 2017 and his newer work is not any different.

    The residence time only shows how much CO2 is moving through the atmosphere, not how much is REmoved out of the atmosphere… In the case of the seasonal cycles, that is the bulk of the natural fluxes, half a year a lot of CO2 is moving from the ocean surface to the biosphere through the atmosphere and the other half it is moving from the biosphere to the ocean surface in the other direction, again through the atmosphere…
    Thus moving a lot of CO2 through the atmosphere and thus reducing the residence time (which takes into account the height of the fluxes, whatever the direction of these fluxes). But that REmoves near zero CO2 out of the atmosphere…

    Only an extra pressure above the dynamic equilibrium between ocean surface temperature and atmosphere (currently 295 ppmv) removes CO2 out of the atmosphere, and that is around 50 years e-fold decay rate or 37 years half life time, not 4 years…

    Thus there are three points where Harde’s (2017) work was fundamentally wrong:

    Using the residence time, or even the decay rate of the 14C bomb tests excess, doesn’t say anything about the time needed to reduce an extra bulk CO2 injection – whatever the source – above the temperature controlled steady state of the oceans with the atmosphere.

    Using the total concentration of CO2 in the atmosphere as base implies a steady state of zero CO2 in the atmosphere, which is not realistic.

    Using only natural emissions without taking into account the natural sinks violates the mass balance.

    See the full critique at:

    And the full explanation why humans are responsible for (near) all CO2 increase in the atmosphere:

    Which doesn’t imply a huge impact on temperatures, which is a quite different discussion…

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