Reconciling predictions of climate change

From Eurekalert,

New framework accounts for conflicting estimates of global temperature increases

Harvard John A. Paulson School of Engineering and Applied Sciences

 

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AUDIO: SEAS researchers Peter Huybers and Cristian Proistosescu resolved a major conflict in estimates of how much the Earth will warm in response to a doubling of carbon dioxide in the… view more

Credit: Harvard SEAS

Harvard University researchers have resolved a conflict in estimates of how much the Earth will warm in response to a doubling of carbon dioxide in the atmosphere.

That conflict — between temperature ranges based on global climate models and paleoclimate records and ranges generated from historical observations — prevented the United Nations’ Intergovernmental Panel on Climate Change (IPCC) from providing a best estimate in its most recent report for how much the Earth will warm as a result of a doubling of CO2 emissions.

The researchers found that the low range of temperature increase — between 1 and 3 degrees Celsius — offered by the historical observations did not take into account long-term warming patterns. When these patterns are taken into account, the researchers found that not only do temperatures fall within the canonical range of 1.5 to 4.5 degrees Celsius but that even higher ranges, perhaps up to 6 degrees, may also be possible.

The research is published in Science Advances.

It’s well documented that different parts of the planet warm at different speeds. The land over the northern hemisphere, for example, warms significantly faster than water in the Southern Ocean.

“The historical pattern of warming is that most of the warming has occurred over land, in particular over the northern hemisphere,” said Cristian Proistosescu, PhD ’17, and first author of the paper. “This pattern of warming is known as the fast mode — you put CO2 in the atmosphere and very quickly after that, the land in the northern hemisphere is going to warm.”

But there is also a slow mode of warming, which can take centuries to realize. That warming, which is most associated with the Southern Ocean and the Eastern Equatorial Pacific, comes with positive feedback loops that amplify the process. For example, as the oceans warm, cloud cover decreases and a white reflecting surface is replaced with a dark absorbent surface.

The researchers developed a mathematical model to parse the two different modes within different climate models.

“The models simulate a warming pattern like today’s, but indicate that strong feedbacks kick in when the Southern Ocean and Eastern Equatorial Pacific eventually warm, leading to higher overall temperatures than would simply be extrapolated from the warming seen to date,” said Peter Huybers, Professor of Earth and Planetary Sciences and of Environmental Science and Engineering at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) and co-author of the paper.

Huybers and Proistosescu found that while the slow mode of warming contributes a great deal to the ultimate amount of global warming, it is barely present in present-day warming patterns. “Historical observations give us a lot of insight into how climate changes and are an important test of our climate models,” said Huybers, “but there is no perfect analogue for the changes that are coming.”

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82 thoughts on “Reconciling predictions of climate change

  1. Consensus science can be summarized as: consistent with, which may be accurate, may be inaccurate, or consistent with one, the other, or both.

  2. “Canonical” means two WAGs from the ’70s, one of 2.0 degrees C per doubling, and another of 4.0 by Hansen, with an arbitrary 0.5 degrees error range, which range hasn’t changed in about 40 years.

    No actual science involved.

    • If this is not true, the current models still fail.

      If turns out to be true, it proves the current models false.

  3. So positive feedback will eventually happen even though it has apparently not yet been observed? And genetic engineering will eventually produce flying pigs?

    • Water in the atmosphere and ocean with CO2 makes bicarbonate, whose radiance is zero. Doubling CO2 in a glass tube increases the temperature, but not detectably on a water planet. The atmospheric models are modelling glass tube radiance, not geochemistry therefore they have no meaning whatsoever.

    • Not clear to me if they are talking about natural warming. Seems as if they are saying that the natural warming can add to the man made warming. Have not read the paper yet, just going from this post.

    • Warming oceans due to CO2 causes increased evaporation which leads to less clouds; the extra evaporated moisture cannot form clouds; no way.

      g

  4. GIGO + Horse Schist =

    The researchers developed a mathematical model to parse the two different modes within different climate models.

    “The models simulate a warming pattern like today’s, but indicate that strong feedbacks kick in when the Southern Ocean and Eastern Equatorial Pacific eventually warm, leading to higher overall temperatures than would simply be extrapolated from the warming seen to date,” said Peter Huybers, Professor of Earth and Planetary Sciences and of Environmental Science and Engineering at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) and co-author of the paper.

    Huybers and Proistosescu found that while the slow mode of warming contributes a great deal to the ultimate amount of global warming, it is barely present in present-day warming patterns. “Historical observations give us a lot of insight into how climate changes and are an important test of our climate models,” said Huybers, “but there is no perfect analogue for the changes that are coming.”

  5. According to Patrick Moore ex Greenpeace 8,000 years ago it was 2C warmer than today with Co2 at 200ppm whereas today we are 2C colder with Co2 at 406ppm so Co2 has doubled and we are colder. Makes as much sense as saying 1 part in 10,000 will cause a catastrophe?

    • Ah, but here we have the Harvard climate, of rarified pedigree and not like our common old one. You know, the one we live in…..

    • And in the long ice core records, CO2 reaches it’s peak AFTER temperatures are heading down into the next glacial period. If the physics of CO2 being the driver is correct, then logically, this could not happen. Ergo, CO2 is not the driver. CO2 concentrations are a follower of temperature, an effect, not a cause. Outgassing from the oceans, and more plant material cycling CO2 into the atmosphere by dying and decaying gives us higher concentrations during warm periods, more CO2 taken up by cooler ocean water (and the ice itself) and less plant growth and thus less plant decay during cool periods (and virtually no plant growth under ice sheets) give us lower concentrations during cold periods.

    • David I see no chance of a two degree rise this century even in a business as usual burning of fossil fuels, however, I wish we could stop this silly 4 molecules of CO2 /10,000 as a measure of insignificance. It makes sceptics less cogent a player.

      The entire biosphere including ourselves were created from half this teeny amount of CO2! Such a miracle should temper our underestimate of this most important molecule. I was struck how fast CO2 dissolves in water when I observed carbonation of water in a kitchen device that made bubbly out of tap water in a second! It an order of magnitude more soluble than salt or sugar. Plants take it in like we breathe air!

      • Instead of 4/10000, how about the over 40/10000 atmospheric CO2 present when the biosphere evolved? Doesn’t the make skepticism more credible? For almost all Earth time for life forms, atmospheric CO2 was 4000 to 7000 ppm, compared to our minuscule 400 ppm.

  6. ‘A slow mode of warming’; so not attributable to CO2? What about cooling, I hope there is a slow cooling mode and not just the sudden drops into starvation.

  7. Patrick Moore also said that between 2000 and 2010 that the planet emitted 100,000 billion tons of Co2. I have also seen somewhere that the IPCC Co2 hypothesis asserts that if Co2 rises then temperature will exhibit a rapid and immediate linear response well between 1997 and 2017 it didn’t only spikes caused by El Nino but no rapid and immediate linear response, strange that?

  8. So models derived from settled science are wrong. So they run those models through another model to find out that…. wait for it… “It’s worst than we thought!”
    Wow.

    • After they run the climate models they run economic models on top of that – a point that Scott Adams has made before. And even if you believed the climate models you should never believe the economic models (which have never reliably predicted anything).

    • One would have thought that “a major conflict in estimates of how much the Earth will warm in response to a doubling of carbon dioxide” would not be an issue in “settled” science. I guess it’s just yet another of the unknown variables which changes meaning, depending on the context/agenda.

  9. It sounds like what he is really saying is:
    The current “global warming” isn’t global at all but really localized in the Northern Hemisphere.
    This sounds almost identical to the MWP that also wasn’t global but hemispheric and localized.

    So it would appear that the current hemispheric global warming is nearly identical to the prior MWP hemispheric global warming period.

    • Yes, I love that. The MWP is not real because it is only NH. But, modern warming is dangerous and global, even though it is mostly NH.

  10. “When these patterns are taken into account, the researchers found that not only do temperatures fall within the canonical range of 1.5 to 4.5 degrees Celsius but that even higher ranges, perhaps up to 6 degrees, may also be possible.”

    And there it was—the neon “This is warmist propaganda” sign.

      • The definition is definitely appropriate to the church of global warming:

        canon1
        ˈkanən/
        noun
        noun: canon; plural noun: canons; noun: canon of the Mass

        1.
        a general law, rule, principle, or criterion by which something is judged.
        “the appointment violated the canons of fair play and equal opportunity”
        synonyms: principle, rule, law, tenet, precept, formula; More
        standard, convention, norm, pattern, model, exemplar;
        criterion, measure, yardstick, benchmark, test
        “the appointment violated the canons of fair play and equal opportunity”
        a Church decree or law.
        “a set of ecclesiastical canons”
        synonyms: law, decree, edict, statute, dictate, dictum, ordinance; More
        rule, ruling, regulation;
        decretal
        “a set of ecclesiastical canons”

        2.
        a collection or list of sacred books accepted as genuine.
        “the biblical canon”

  11. “For example, as the oceans warm, cloud cover decreases and a white reflecting surface is replaced with a dark absorbent surface.”
    ??? As the oceans warm, convection over them increases, increasing cloud cover. Warmer oceans pump more moisture into the higher atmosphere, including cirrus clouds which are highly reflective. So, is the rest of their science this bad?

    • Yes, I picked up on that one too. People who make statements about warming oceans and cloud cover should visit the tropics during the wet season. The phenomenon is the exact reverse of what they say.

      It’s as though they all live where the warmer months are indeed drier.

    • Mumbles,
      I was about to make the same comment, and you beat me to it. That statement really needs a citation by the authors to support what is a counterintuitive conclusion.

    • Just what I thought on reading it – but then I’m not a climate scientist or a witch doctor.

    • Pretty sure Willis did some work proving the exact opposite. Namely that the warmer it it at the tropical ocean the earlier and larger the clout cover.

      In fact, it would seem self evident. Why would ANYONE think warmer would lead to less clouds?

  12. Another model that proves that previous models were right all along.

    What a relief to learn that the science really is settled.

    • The illusion of global warming?

      And the illusion of melting sea-ice and the illusion of receding glaciers and the illusion of rising sea-levels and the illusion of coral bleaching and the illusion species migration and flowering and fruitin time changes, etc, etc.?

      They aren’t illusions Tadchem, there is a mountain of well-documented research published in respected Science Journals about all of these “illusions”.

      • Yes, the planet is experiencing a normal interglacial warming, as has been observed in the long term record.
        -Receding glaciers should be expected.
        -Sea levels continue to rise in the same manner they have for centuries.
        -Coral bleaching is not a product of climate or CO2.
        -Migration of species is nothing new and has occurred countless times before humans were here. In fact it appears that humans have also been migratory due to past climate changes.
        -My fruit trees flower at different times depending on the weather that particular year. Sometimes the flowers are frozen off by late hard freezes in late April or winter temps of -15 F or so. People around here can only grow plants from the next zone south in sunny locations enhanced by UHI.

        As for etc, etc?
        I’ll leave that to miscellany.

      • Sea ice melted prodigiously in the 1920s. Glaciers receded more in the 1800s than 1900s (see Glacier Bay map). Sea level has been rising steadily at one millimeter per year (four inches per century) for over 100 years since the end of the Little Ice Age, with no acceleration; sea level was higher on the West Coast of the US and Canada in 1983 than in 2016 (go to PSMSL.org, and NOAA’s record of 199 long tide gauge records). Coral bleaching is an adaptive natural reaction to changes in the coral’s environment, and the other “illusions” you mention are well documented reactions to natural climate change. As examples, tree lines have been much farther north and at much higher elevations during the Holocene Climatic Optimum 9,000 to 5,000 years ago than now, and trees, unlike humans, can’t lie about their reactions to natural climate change. All of the above is well documented research published in respected science journals, and the tide gauge information is readily available from PSMSL and NOAA online for those interested in verifying it for themselves. It’s amazing how few science writers find the time to do the easy and obvious to verity sea level claims.

      • Are you thinking of the West Antarctic ice sheet which is being pushed into the Southern Ocean as a result of gigatons of new ice being laid at the top every year?

  13. Are they avoiding the use of land data that has consistently been demonstrated as exaggerating temps? Urban island heating , which exaggerates temps, is mostly occurring in the northern hemisphere.

  14. The researchers developed a mathematical model …

    I bet their model can’t be validated.

    There are principles for the verification and validation of models.

    The expected outcome of the model V&V process is the quantified level of agreement between experimental data and model prediction, as well as the predictive accuracy of the model. link

    As far as I can tell, no climate models can be verified and validated.

      • Doesn’t matter how you get there, as long as you arrive at the proper conclusion. Progressive rule #13.

    • Bob,
      Every time I bring up this point, the CAGW proponents/modelers do a lot of hand-waving that amounts to “we don’t need no stinking V&V”. My retort is, “then I don’t believe your stinking results”. This should be every thinking person’s response, but sadly it is not.

    • “What model formulations are most useful for representing the
      heterogeneous evolution of the forced response of GCMs remains
      a subject of ongoing research, but it is possible to generically repre-
      sent generically how global mean temperature evolves in existing
      simple models (complicated non-linear equation), or any other linear system, using ei-
      genmode decomposition.”

      Straw man argument- non of the existing climate models are simple or linear. Neither is the climate.

      Use of linear models is always only the first rough guess at a model. None of the climate processes except the final one- incoming energy=outgoing radiation (or we’d all be dead by now). Applying eigenmode decomposition to the non-linear processes adds multiple orders of magnitude to the difficulty of an already intractable problem. Even the unrealistic, limited current climate models can’t be modeled, much less solved. Adding an untestable layer on the top makes the results meaningless.

    • Even after Oreskes isn’t an issue, Harvard doesn’t need more money. And other recipients are worthier.

    • Maybe best save your money for needed new institutions. We might have to let the venerable institution go. Oxford and Cambridge still get billings as top world universities, but I would consider sending my children to Missouri instead.

  15. Are any of these “climate scientists” churning out studies over 25 years old?

    • A useful rule of thumb in alarmist articles is to stop reading at the first “could”. It is at that point that the author’s tacitly admit they have no idea.

    • Essentialy there are no much new aspects in this paper, the only one is a lower “ICS” of about 2.5 which is nearer to the observed value:

      (bottom)
      If this assumption would be a mistake ( I’m quite sure it is) and the real value is well above the observations ( i.e in the near of 3) than we would have a new take home message:
      “There is a major conflict between models and obs.”
      A step foreward!!

  16. Has anyone proven a mechanism by which greenhouse gasses heat the oceans?
    Seems far-fetched to believe that the atmosphere somehow determines ocean temps.

      • The oceans now are in their coolest phase of the past 10,000 years, which correlates well with global temperature which also is in the coolest period of the past 10,000 years, as determined by Greenland ice core and Atlantic and lake sediment core studies. Tree lines are further south and at lower elevations than 9,000 to 5,000 years ago. Nature has the signs out that climate change is natural, but many scientists are knowingly avoiding reading the signs.

      • TD, perhaps you forgot the sarc? Backradiation cannot warm oceans. Perhaps a little evaporative cooling from the ‘skin’ hit by non penetrating IR. Oceans are warmed by incoming short wave solar radiation mostly in visible light energies/frequencies, which depending on frequency do get down about 100 meters, the photic zone where marine photosynthesis can occur.They are cooled by evaporation and by emitted IR.
        The ‘greenhouse effect’ is just an absence of sufficient radiative IR cooling. GHG retard radiative cooling. Greenhouse is a misnomer, since real greenhouses work by retarding convective cooling. Since earth is surrounded by the vacuum of space, neither convective nor conductive cooling works. Got to be radiative.

      • I’ve only know this theory to be unproven in nature. What solid evidence is there of how much back-radiated warming has affected the total heat content of the oceans?

      • Ristvan, if you say that the back-radiation cannot penetrate to warm, then you cannot say they are cooled by emitted IR. You see, the warm water a few mm below the surface cannot emit IR, because the water above it absorbs it and can’t get out.

      • Rud,
        Isn’t it always amazing how the CAGW crowd talks about “down-dwelling LW radiation”, but not the up-dwelling part? Half of all the energy absorbed by CO2 and reemitted is upwards and is not “trapped”.

      • Martin,
        You have forgotten about conduction and convection. By these mechanisms heat can be transferred to the surface of the ocean where it can warm the atmosphere by radiation, and conduction. The reverse is also true, but because the density and mass of the ocean is so much greater than the air, the energy flow (direction and amount) is dominated by the oceans.

      • Paul you say: “the energy flow (direction and amount) is dominated by the oceans.” No, you are wrong. The energy flow is dominated by the penetration of visible light from the sun into the ocean.

      • The oceans were warmer 9,000 years ago when atmospheric CO2 was only 280 ppm. Low atmospheric CO2 didn’t prevent the end of the glacial period, and increasing atmospheric CO2 hasn’t reversed the 10,000 year ocean cooling trend.
        “A paper published today in Science is devastating to anthropogenic climate alarm, finding reconstructed Pacific Ocean heat content has been significantly higher throughout the vast majority of the past ~10,000 years in comparison to the latter 20th century. In addition, according to the comment by the editor of Science, “The findings support the view that the Holocene Thermal Maximum, the Medieval Warm Period, and the Little Ice Age were global events, and they provide a long-term perspective for evaluating the role of ocean heat content in various warming scenarios for the future.”
        ” Between 10,000 and 8,000 years ago, at depths between 500 and 1,000 meters, the Pacific Ocean was some 2 degrees Celsius (3.6 degrees Fahrenheit) warmer than today for many centuries.”

      • majormike1
        “A paper published today in Science is devastating to anthropogenic climate alarm,

        Did you read the paper mike? It wasn’t “devastating to anthropogenic climate alarm” at all was it?
        The take-out message was in fact that in the last 150 years the ocean is warming an order of magnitude faster than at any time during the Holocene.

        Perhaps you’re just looking through the wrong end of the telescope.

      • The paper said the warming was from the coldest period of the past 10,000 years. the Little Ice Age. Did you read “The Two-Mile Time Machine” that also places current warming in the coldest 10% of the past 10,000 years. Current ocean warming began at the end of the Little Ice Age, about 1850 AD, long before any significant increase of atmospheric CO2. You can’t have a physical forcing (higher atmospheric CO2) retroactively be the cause of ocean warming. Jus t as atmospheric CO2 was not the cause of the much greater ocean warming 10,000 years ago. When I pointed this out on an Antarctic voyage to an eminent retired NASA scientist, his answer was “It’s different now.” Is that your answer too? The ocean was 2 degrees Celsius warmer then, atmospheric CO2 was 30% lower – what role did greenhouse gasses play in the very rapid warmup of the oceans which followed the 100,000-year glacial period? What made it different then?

      • “It’s as complicated as putting on a jacket and making your skin temperature rise.”

        Interesting comment. You do know that your jacket doesn’t work by preventing radiation, but actually by preventing convection, don’t you?

        Interestingly, this is the exact way that greenhouses work. Unlike the “greenhouse effect”, which doesn’t (work, that is).

    • “This is supported by observations on land where the overpassing air mass takes on the characteristics of the underlying surface, achieving energy balance within a 300 m distance (Morton, 1983). When passing from land to water, this will see all of the available heat energy taken up by water if the temperature of the air mass exceeds that of water (Morton, 1983, 1986), with the temperature of the overpassing air mass reaching equilibrium with the water beneath within a very short time. Very little of the heat trapped over land can be absorbed by the land surface, but will be transported from land to ocean within a few days to a few weeks, where it can be absorbed (the high latitudes being an exception).”

      https://wattsupwiththat.com/2017/03/31/a-ground-breaking-new-paper-putting-climate-models-to-the-test-yields-an-unexpected-result-steps-and-pauses-in-the-climate-signal/comment-page-1/

      If GHGs can warm the atmosphere, the atmosphere can warm the ocean as above. If it didn’t warm the ocean above, where did the joules go?

    • It’s complicated. link The ocean loses heat when it warms the atmosphere by conduction and radiation. If the atmosphere is warmer, the ocean loses less heat by this mechanism. On the other hand, warmer air holds more moisture and the ocean will lose even more heat due to evaporation. Thermodynamics is a [snip].

  17. “On the other hand, he said, other parts of the planet — namely, the Southern Ocean and the eastern Pacific — respond much more slowly, in part because they’re just so deep and cold to begin with.”

    “While the impact of these processes may be profound, they can also take long periods of time to unfold, Proistosescu said — potentially up to 300 years or so.”

    https://www.washingtonpost.com/news/energy-environment/wp/2017/07/05/scientists-are-starting-to-clear-up-one-of-the-biggest-controversies-in-climate-science/

    The oceans are not having the SSTs needed to push the GMST high enough. The land is easier to warm and more or less did what was expected. Looks like the oceans thermal mass does matter.

    The future warming is going to take awhile to get here. According to Scripps, the warming at 1000 meters of depth is 0.1 C per century. I assume sufficient vertical ocean mixing.

  18. “For example, as the oceans warm, cloud cover decreases”

    That’s funny, I would have thought the opposite.

    As the oceans warm, they retain their typical temperature advantage over the atmosphere. They evaporate (latent), radiate (sensible), and conduct (sensible) more energy to the atmosphere. The surface boundary layer of then atmosphere is then warmed.

    Not really much else.

  19. “as the oceans warm, cloud cover decreases”

    That makes no sense at all. Warming oceans increase the humidity of the atmosphere and that increases the cloud cover. If they are wrong on such a fundamental point, can there be any validity in the rest of the article?

  20. ristvan:Your description of the ocean surface energy balance is incomplete.Absorbed sky I.R.(back) radiation is about 350 W/m^2 c.f.emitted I.R. of about 400 W/m^2 and evaporation of about 80 W/m^2.Now complete the balance to understand the role played by sky radiation.

  21. I’ve heard an estimate that nearly 60% of the 7+ billion people on Earth live in cities! The one adjustment the AGW crowd won’t use is the UHi factor, which is 2+C. If they ever acknowledge and incorporate that cooling adjustment, I might begin to take them seriously! Nah, neither will ever happen! 😰

  22. As with the majority of research in “climate science,” the categorical distinction between in situ dynamics and model behavior is greatly blurred in this study. Nowhere is there any indication that their model has been subjected to any rigorous validation.

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