Max Planck Institute Climate Modeler Admits: “Reprieve Extended 10 Years” …”Earlier Models Too Sensitive”!

Climate modeler Jochem Marotzke: more time to decarbonize, earlier climate models were too sensitive

Correction (12 November 2018): Dr. Lüning writes that he had to modify his post on Marotzke a bit. “Marotzke did not mean CO2 climate sensitivity but that more CO2 is buffered, adding less to the atmosphere.” However, the goalposts still have been moved back and we still get 10 more years.

Hat-tip: Sebastian Lüning and Fritz Vahrenholt

On October 5, 2018, German national weekly Spiegel here presented a noteworthy interview with Germany’s top climate modeler, Jochem Marotzke, director of the Max Planck Institute for Meteorology in Hamburg.

Top German climate modeler, Jochem Marotzke, Director of the Hamburg-based Max Planck Institute for Meteorology. Image: Max Planck Institute for Meteorology.

Spiegel wrote in its sub headline:

Unexpected extra time in the climate scenario: ‘Our reprieve has been extended by about ten years’ Physicist and climate researcher Jochem Marotzke explains why humanity has more time to stop global warming than previously thought.”

Or in other words, German skeptics Dr. Sebastian Lüning and Prof. Fritz Vahrenholt write at their Die kalte Sonne blog, “the sensitivity of CO2 was obviously overestimated.”

Yes, the climate goalposts just got moved back once again.

Earlier skeptic claims of overly sensitive models now spot on

More than 6 years ago in 2012, Lüning and Vahrenholt had already pointed out the problem of over-sensitive models in their book “Die kalte Sonne” – a claim that Marotzke back then said was “completely outlandish”.

Naturally today Lüning and Vahrenholt find themselves somewhat vindicated, and are confident more vindication is on the way as the reality of climate change becomes increasingly known.

We can emit “at least twice as much”

In the Spiegel interview, conducted editor Olaf Stamp, Marotzke was asked about how much CO2 we could still add to the atmosphere:

MAROTZKE: […] According to the latest climate scenarios, the amount of CO2 that we may emit is far greater than previously assumed – a fundamental point.

SPIEGEL: So we’ve been given amore time to reduce CO2 emissions?

MAROTZKE: Exactly. That’s what today’s improved models show. Our remaining CO2 budget for the 1.5°C target is in fact at least twice as much as previously thought: almost 1 trillion tonnes. Thus our reprieve has been extended about 10 years. Of course, it makes a huge difference if we have to bring the emissions of greenhouse gases down to zero in 15 years or 25 years. I assume that this will be the key message in the special report.”

And, according to Marotzke:

Our earlier models are too sensitive in one crucial place […]”

Here the Hamburg-based Max Planck Institute for Meteorology director is talking about CO2 climate sensitivity. And Lüning and Vahrenholt write: ” And when Marotzke says this, then it has real weight.”

IPCC Report politicized, “long deviated from the scientific basis”

In the Spiegel interview, which took place three days before the IPCC report was released, Marotzke suspected that the 1.5-degree report of the IPCC was to play down the danger of climate change. But when the report came out, it conveyed the opposite, namely worsened climate warnings.

This, according to Lüning and Vahrenholt, “is an indication that it is more a political report than a scientific account. Apparently the IPCC report authors, handpicked by politics, have already long deviated from the scientific basis.”

1.5°C target ” came as a surprise to us climatologists”

When asked by Spiegel why the 1.5°C target was used instead of 2°C:

SPIEGEL: Why was the limit lowered from 2 degrees to 1.5 degrees?

MAROTZKE: That came as a surprise to us climatologists as well. Especially the West Pacific island states insisted on 1.5 degrees at the Paris negotiations because they would be threatened by the rise of the sea level already at 2 degrees. However in most parts of the world, especially in Europe, we do not expect much difference between a 1.5-degree world and a 2-degree world.”

Politics overruling science

“Once again, political motives were more important than science,” Lüning and Vahrenholt write in response to Marotzke’s comments.

“Curiously enough, the Pacific Islanders also ignore the fact that they live on growing coral islands, which have already withstood much stronger sea-level rise rates in the transition from the last ice age to today’s interglacial. One has to assume that, above all, this should accelerate the path to the international coffers for climate compensation payments,” say skeptics Lüning and Vahrenholt.

The whole Spiegel interview is behind a paywall at

Rejects claims of tipping points taking place

Marotzke also explained that signs of the alleged tipping points coming from the Potsdam Institute were rather weak. He also flat out rejected the tipping points of a stalling Gulf Stream and melting West Antarctic.

21 responses to “Max Planck Institute Climate Modeler Admits: “Reprieve Extended 10 Years” …”Earlier Models Too Sensitive”!”

  1. oebele bruinsma

    Ten years more of the gravy train…

    1. Bitter&twisted

      Spot on.
      That was going to be what I was going to say.
      Marotzke is a cynical scamster.
      Just like most climate “scientists”

  2. Curious George

    Did they really issue climate ultimatums based on faulty models? How many trillions have been misspent?

  3. EDMH

    here is a goodish guess of the extra costs of Weather dependent Renewables of Gas Fired installations

    EU (28). about EURO 2 TRILLION.


  4. toorightmate

    Gee, a 1.5 degree world would be very cold.

  5. RickWill

    I was once employed to monitor the construction of a large industrial complex where I would eventually be involved in its operation. After monitoring the project for almost 12 months I made a simple plot of the projected completion date against the date of issue of each monthly report. The resulting plot did not intersect the line of common date; meaning the construction would never end if it remained on its current trajectory. That simple chart motivated a dramatic acceleration in effort; resulting in much faster progress and ultimately saving money.

    The time extension is this story brings me back to that project. If you are riding the gravy train you have to make the journey seem plausible and hopefully lasting forever (that project was located on an idyllic tropical coast). The destination will never arrive because it will always be 5 years or 10 years off in the future. As we reach each announced tipping point it will be declared that we have managed to postpone it for a few more years but it is still worse than we thought.

  6. Kurt in Switzerland

    Confirmation bias is indeed a powerful force.
    It is an obstacle to scientific progress.

    Read up on Milliken’s Oil Drop..

    When you marry politics and science, this phenomenon repeats and even expands upon itself. Expecting otherwise is the quintessence of naïveté.

    1. sasquatch

      Had to check out Millikan’s experiment.

      Millikan’s experiment

      1. Yonason

        Another experiment of Millikan’s worth noting is his confirmation of Einstein’s Photoelectric Effect.

        Millikan was none to happy to have shown it to be true, either (see article), but being an honest scientist he had no choice but to tell the truth.

        Fast forward to today, and ask how many scientists would bother testing a theory they “knew” a priori to be “false.” Einstein would not only not be awarded the Nobel Prize, but would probably be so marginalized for his one crazy idea that he’d end up being a patent clerk for life. And great discoveries wouldn’t be made, because of small minded nitwits with an agenda.

  7. MGJ

    This doesn’t sit so well with papal-style claims of infallibility, does it?

    “We’re terribly sorry, we got it wrong and the science wasn’t settled after all”, said…nobody.

    1. Henning Nielsen

      No, no. “We are not sorry, the science is right all along, we have made a minor adjustment and you still have to do exactly as we say. And pay.”

  8. skeptik

    One of the problems associated with the making any projections about futue temperatures is that nobody really knows what the sensitivity of temperatures to CO2 really is. There is a very wide range of estimates to be found in the peer reviwed literature. The lowst is 0.1 degrees C and the highest is 9.6 for a doubling of CO2. In its AR5, the IPCC gives a range of 1.5 to 4.5 but this is still huge.

    If most of the warming that we have actually seen were really down to increased CO2, one would expect to be able to get a much narrower range of possible sensitivities than we do. This must cast doubt on a significant part of the AGW orthodoxy.

  9. Top Climate Scientist: “Reprieve Extended 10 Years - Climate Models Were Too Sensitive" - The Global Warming Policy Forum (GWPF)The Global Warming Policy Forum (GWPF)

    […] Full post […]

  10. Dr Tim Ball - Historical Climatologist

    On Feb 13, 2018: The judge dismissed all charges in the lawsuit brought against Dr Tim Ball by BC Green Party leader Andrew Weaver. It is a great victory for free speech.
    ‘The Deliberate Corruption of Climate Science’.
    “Human Caused Global Warming”, ‘The Biggest Deception in History’.

  11. Yonason
  12. Pete Ridley

    Quote from Wikipedia ” .. The judge noted that Ball’s words ‘lack a sufficient air of credibility to make them believable and therefore potentially defamatory’ and concluded that the ‘article is poorly written and does not advance credible arguments in favour of Dr. Ball’s theory about the corruption of climate science. Simply put, a reasonably thoughtful and informed person who reads the article is unlikely to place any stock in Dr. Ball’s views…” (

    ‘Nuff said!!!

  13. secryn

    Man goes to doctor.
    Doctor says “Bad news. You’ve only got 6 months to live.”
    Man says “But I won’t be able to pay you for a year.”
    Doctor says: “Good news. I’ll give you another 6 months.”

    Rodney Dangerfield had the whole scam figured out 30 years ago.

  14. John McLean

    Marotzke now says that more CO2 is buffered than was previously thought. I find that odd given that the annual increase in atmospheric CO2 has for decades been about 50% of the estimated manmade CO2 emissions. Modellers would surely have been aware of that figure. I think Maroktzke is trying to find excuses.
    The other interesting thing about that percentage is that it’s been much the same – higher in El Nino years, lower in La Nina years – regardless of the concentration of CO2 in the atmosphere. It was about the same at 300ppm as it was at 400ppm, so it looks like the biosphere is quite capable of absorbing additional CO2.

  15. Homepage

    … [Trackback]

    […] Read More: […]

  16. Rosco

    I have a mathematical and blackbody radiation based physical proof that the only simple model of the “greenhouse effect” is WRONG.

    The algebra of this model is explained here :-

    The algebra is plain and simple.

    239.7 W/m2 + 239.7 W/m2 = 479.4 W/m2 and the Stefan-Boltzmann equation says this equates to a temperature of 303 Kelvin.

    I wrote an article several years ago and I present it here:-

    I use Planck curves for the temperatures quoted in the Washington University lecture – the solar insolation alone induces ~255 K surface temperature.

    They then add the 239.7 W/m2 atmospheric back radiation – again from a 255 K atmospheric layer – to arrive at 479.4 W/m2 emitted by the surface heated by both solar and atmosphere.

    I show this sum fails to produce the Planck curve for 303 Kelvin and is therefore indisputably wrong.

    Remember everybody seems to think you can add up discrete radiative fluxes and calculate the temperature BUT when you perform EXACTLY the same sum using Planck curves and the rules of calculus the algebra fails TOTALLY.

    Surely if the algebraic sum causes the temperature then the EXACT same sum involving calculus must give the same answer yet it doesn’t.

    Planck’s equation is universally accepted as right for blackbody radiation as is the Stefan-Boltzmann equation !

    Therefore the only thing wrong with the simple model of the “greenhouse effect” is the assumption that the algebraic manipulations MUST be invalid – adding 2 discreet fluxes and calculating the resulting temperature is NOT physically valid !

    I’m not stating that at 255 K or 303 K the emissions are not correct in the lecture BUT I am saying the algebraic sun is wrong !

    Try it yourself by plotting Planck curves using ANY combination of temperatures in whatever domain you chose – frequency, wavelength or wavenumber – the algebraic sum fails to deliver a result consistent with Planck’s equation EVERY time !

    If the basic simple algebra is wrong, which it is, then every model that employs such an algebraic sum, they all do, must also be wrong.

    This needs to be discussed ! I cannot understand why it isn’t !

  17. Weekly Climate and Energy News Roundup #336 | Watts Up With That?

By continuing to use the site, you agree to the use of cookies. more information

The cookie settings on this website are set to "allow cookies" to give you the best browsing experience possible. If you continue to use this website without changing your cookie settings or you click "Accept" below then you are consenting to this. More information at our Data Privacy Policy