Scientists try to explain why climate models can’t reproduce the early-2000s global warming slowdown

Posted: May 18, 2021 by oldbrew in climate, modelling, Natural Variation, Temperature
Tags:
model_warm

Climate models overheating

Explanation, or vague excuses? They seem to be saying the models are a wonder, just a shame they don’t reflect reality – mainly due to pesky natural variation.
– – –
A new study led by Dr. Wei and Dr. Qiao from the First Institute of Oceanography, Ministry of Natural Resources provides an evaluation of the performance of the newly released CMIP6 models in simulating the global warming slowdown observed in the early 2000s, says Phys.org.

This study reveals that the key in simulating and predicting near-term temperate change is to correctly separate and simulate the two distinct signals, i.e., the human-induced long-term warming trend and natural variabilities, especially those at interannual, interdecadal and multidecadal scales.

This work was published in SCIENCE CHINA Earth Sciences on April 15th, 2021.

After the unprecedented warming over the last quarter of the 20th century, global surface temperature growth slowed unexpectedly during 1998-2013 despite the sharp increase in greenhouse gas emissions; this phenomenon is termed the global warming hiatus, or slowdown, to be more precise.

The global warming slowdown challenges the existing scientific understanding of global temperature change mechanisms, and thus has been one of the most concerning issues in recent climate research and public debate.

However, the sophisticated and advanced climate models in CMIP5 could not simulate this warming slowdown. [Talkshop comment: ‘could not simulate’ and ‘advanced’ don’t go together too well].

During 1998-2013, the models mostly present a rapidly warming surge which greatly deviates from the observed flat temperature time series. The models considerably overestimate the observed warming rate of the recent period.

IPCC AR5 stated: “Almost all CMIP5 historical simulations do not reproduce the observed recent warming hiatus.” Therefore, the simulation and prediction ability of sophisticated climate models have been questioned.

Now the CMIP6  data are gradually released since 2020. The newly developed models include better understanding of the global temperature change mechanisms, especially more reasonable physical processes of natural variabilities.

Successful simulations of the global warming slowdown are expected in the new-generation models. As the data of 28 new models become available, it is necessary to examine the ability of the CMIP6 models in addressing the recent warming slowdown.

By comparing six widely used global surface temperature datasets, a research team from First Institute of Oceanography, Ministry of Natural Resources evaluated the performance of the 28 newly released CMIP6 models in simulating the recent warming slowdown, and finds that most CMIP6 models still fail to reproduce the warming slowdown, although they present some encouraging improvements when compared with CMIP5 models.

Full article here.

Comments
  1. The Arctic has opened and snowfall has increased, models forecast less snowfall, simple stuff. They have no understanding that Ice thawing is part of the climate balance. It snows more in warmer times and more ice thaws and reflects and causes cooling later, We are in the more snowfall phase, this will last a few hundred years as all warm periods in the last ten thousand years has lasted.

  2. Graeme No.3 says:

    What are they concerned about? Those models are hopeless at explaining the last 450 million years, so what is 20 years of failure?
    And since when is 0.5℃ “unprecedented”?

  3. oldbrew says:

    All the alarmist rhetoric fell flat when the loudly predicted imminent disappearance of Arctic summer sea ice failed to happen, thus undermining whatever credibility they might have had in some quarters.

    Now the low-sunspot solar cycles are here, the prospect of seeing such scenarios any time soon is fading fast. Basing global temperature predictions on graphs of trace gases is busted.

  4. Gamecock says:

    Climate change (sic) is the biggest problem . . .

    ‘The global warming slowdown challenges the existing scientific understanding of global temperature change mechanisms, and thus has been one of the most concerning issues in recent climate research and public debate.’

    Global warming slowdown is concerning? Not good news, but concerning?

    ‘After the unprecedented warming over the last quarter of the 20th century’

    Man has had no way to measure global temperature until the satellite era, circa 1979. So data from ‘the last quarter of the 20th century,’ and 20 years of this century, is all we have. ‘Unprecedented’ is a farcical fabrication.

    ‘The newly developed models include better understanding of the global temperature change mechanisms’

    All previous models have been falsified.

    ‘finds that most CMIP6 models still fail to reproduce the warming slowdown, although they present some encouraging improvements when compared with CMIP5 models’

    And First Institute of Oceanography and Ministry of Natural Resources issue no apology, no contrition, no admission that they don’t know what the heck they are doing.

    ‘encouraging improvements when compared with CMIP5 models’

    Not much to hang your hat on.

    ‘This result can provide important insight for the simulation and prediction of near-term climate changes.’

    No. They can’t. You just spent the entire article telling us they were useless.

  5. ‘All the alarmist rhetoric fell flat when the loudly predicted imminent disappearance of Arctic summer sea ice failed to happen.’

    The polar climate cycles with alternating warm and cold periods is totally self correcting. Greenland depletes of enough ice to chill the gulf stream, the sea ice is removed and more evaporation and snowfall rebuilds the sequestered ice until Greenland is again dumping enough ice into the gulf stream to form sea ice again.

    This is Simple Knowledge, if you just study Greenland Ice Core Records.

    Ice accumulation is most in the warmest times and it gets colder later when the more ice is spread and dumping in the oceans and spreading on the land and causing more cooling by reflecting and thawing.

    Ice accumulation is least in the coldest times and it gets warmer later when the depleted ice retreats and cools the land less with thawing and reflecting and cools the oceans less with less ice dumped into saltwater currents.

    I repeat, this is Simple Knowledge, if you just study Greenland Ice Core Records.

  6. ‘The newly developed models include better understanding of the global temperature change mechanisms’

    All previous models have been falsified.

    The new models are based on the same flawed theory. Climate change is dynamic with warm and cold capacitance in the natural response. Models are based on static climate response with climate always moving toward a new equilibrium. This simple junk can never work.

    They do not understand anything better, they got bigger, faster, computers and they can pump out wrong answers faster, That is not for the better.

  7. tom0mason says:

    These wretched models rely on a fiction of energy balance.
    Since when did the incoming solar energy equal the outgoing energy, and why should it?
    During the run-up to and the peak of a climatic warm period, does the oceans take-up solar energy along with all the rest of nature (microbes, plants and animals proliferate)? During a climatic cooling does not the the planet initially shed more energy than it gains (inertia of shedding the excess)? Solar energy moderates the totality of life on the planet and modifies the amount of energy required to sustain it.
    The bottom line is that during any period of this fictional ‘energy balance’ the result is skewed one way or the other because the climate process is NOT a closed system! And the skewing does NOT have to balance arithmetically.

    These ‘climate models’ assume a closed system and are built on guesstimates and approximations of a climate process that is in continual flux.

  8. Scute says:

    It would be useful if you included the time scale along the x-axis, as it’s usually shown, on the graph at the top of the page.

  9. cognog2 says:

    These models will never get it right if they continue to ignore the basic thermodynamics of water and consign to it the secondary role of a positive feedback. A fundamental error.
    It is a group mindset problem as the Hydrocycle operates independently of radiation and GHE considerations so is inconvenient to incorporate.
    In fact the Hydrocycle provides a strong NEGATIVE feedback to any increase in global energy input, whether by the purported GHE or not. Daily evidence of this is found in our steam generating plants where an increase in energy input is matched by an increase in energy output at constant temperature and pressure.

  10. tallbloke says:

    “the unprecedented warming over the last quarter of the 20th century”

    It’s true that it looks less precedented since they ‘adjusted’ the pre-war data.

    Scute: Here you go.

  11. oldbrew says:

    This version shows the balloon and satellite data for comparison. When your software says CO2 rise = extra warming, you get duff results.

    Climate and the changing sun (1977)
    John A. Eddy
    In every case when long-term solar activity falls, mid-latitude glaciers advance and climate cools; at times of high solar activity glaciers recede and climate warms.

    https://link.springer.com/article/10.1007/BF01884410

    In 1987 Eddy was awarded the Arctowski Medal by the National Academy of Sciences for studies in solar physics and solar-terrestrial relationships and specifically for “his demonstration of the existence and nature of solar variations of long term and the consequences of these changes for climate and for mankind.”

    https://en.wikipedia.org/wiki/John_A._Eddy#Post-academia

  12. Phoenix44 says:

    I could have told them that!

    If you are trying to model ANYTHING with more than one component you need to know which bit is doing what.

    Is this a serious paper or a joke?

  13. Phoenix44 says:

    Scientists try to explain why models they claim are accurate and should be used to completely change societies and economies aren’t.

  14. Chaswarnertoo says:

    GIGO. And the models are crap, too.

  15. oldbrew says:

    The modellers can’t or won’t grasp that ‘the unprecedented warming over the last quarter of the 20th century’, whether unprecedented or not, is history. The fact that they need to refer to the 20th century in that statement is a clue.

  16. craigm350 says:

    Reblogged this on WeatherAction News and commented:

    The results show that although the CMIP6 models present some encouraging improvements when compared with CMIP5, most of them still fail to reproduce the warming slowdown. They considerably overestimate the warming rate observed in 1998–2013, exhibiting an obvious warming acceleration rather than the observed deceleration. This is probably associated with their deficiencies in simulating the distinct temperature change signals from the human-induced long-term warming trend and or the three crucial natural variabilities at interannual, interdecadal, and multidecadal scales.

    It’s not our theories, we need more money 🙄

  17. Ron Clutz says:

    Trying not to sound like a broken record, but there is one model INMCM5 that does replicate the past, but is disregarded because its future projections are not alarming.

    Figure 1. The 5-year mean GMST (K) anomaly with respect to 1850–1899 for HadCRUTv4 (thick solid black); model mean (thick solid red). Dashed thin lines represent data from individual model runs: 1 – purple, 2 – dark blue, 3 – blue, 4 – green, 5 – yellow, 6 – orange, 7 – magenta. In this and the next figures numbers on the time axis indicate the first year of the 5-year mean.

    More at https://rclutz.com/2020/12/02/climate-models-flagged-for-running-out-of-bounds/

  18. stpaulchuck says:

    Once again I refer to the IPCC’s own science mavens on predicting a complex chaotic system, in particular when you kick the sun to the curb.

    ———-
    “The climate system is a coupled non-linear chaotic system, and therefore the long-term prediction of future climate states is not possible.” – IPCC TAR WG1, Working Group I: The Scientific Basis
    ————–
    “Computer models are no different from fashion models. They’re seductive, unreliable, easily corrupted, and they lead sensible people to make fools of themselves” John in OK
    ———-
    “The influence of mankind on climate is trivially true and numerically insignificant.” – Dr Richard Lindzen

  19. hunterson7 says:

    Not to put too fine a point on it, but the article is written to deceive, not inform.

  20. oldbrew says:

    most CMIP6 models still fail to reproduce the warming slowdown, although they present some encouraging improvements when compared with CMIP5 models

    Being less wrong = ‘encouraging improvements’ 🙄

  21. oldbrew says:

    UK temperatures are way down on May averages…

    UK weather: May on track to be wettest on record with more rain to come
    Rainfall totals across UK exceed monthly average with flood warnings in England and Wales

    Fri 21 May 2021

    According to provisional figures from the Met Office’s national climate information centre, Wales has already recorded 129% (110.6mm) of its average rainfall for the whole of the month, while the UK as a whole has had 88% (61.1mm).
    . . .
    Simon Partridge, a senior operational meteorologist at the Met Office, said: “After a very dry April, the UK has seen a very wet May with rainfall totals already exceeding the monthly average.

    “This has primarily been as a result of the position of the jet stream. It is currently to the south of the UK which allows low-pressure systems (those which bring wind and rain) to cross the UK.
    . . .
    The Met Office has reported May to be a relatively cool month, despite average temperatures in the UK increasing due to climate change, with maximum, minimum, and mean temperatures all at least 2C lower than the May average for every part of the UK.
    [bold added]

    https://www.theguardian.com/uk-news/2021/may/21/uk-weather-may-on-track-to-be-wettest-on-record-with-more-rain-to-come
    – – –
    Where’s our global warming? 🤔

  22. arfurbryant says:

    Suggestion to modellers…

    1. Remove any input of radiative forcing from your model.
    2. Remove any other assumed anthropogenic warming factor.
    3. See if the output more closely matches reality.

    Go on, I dare you.

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