Another climate feedback found: ‘cooling effect of natural atmospheric particles is greater during warmer years’

In this image from NASA, global aerosol loads in the atmosphere are visualized by satellite. Full story here: https://wattsupwiththat.com/2017/11/19/fantastic-visualization-of-earths-atmosphere-in-2017/

 

From the University of Leeds and the “settled science” department, comes this new idea that combines measurements with a model.

Understanding the climate impact of natural atmospheric particles

An international team of scientists, led by the University of Leeds, has quantified the relationship between natural sources of particles in the atmosphere and climate change.

Their study, published today in Nature Geoscience, shows that the cooling effect of natural atmospheric particles is greater during warmer years and could therefore slightly reduce the amount that temperatures rise as a result of climate change.

Particles in the atmosphere can alter Earth’s climate by absorbing or reflecting sunlight. These particles are often produced by human activities, such as from cars and industry, but there are also naturally occurring particles.

The team combined atmospheric measurements with a computer model to map the effects of two natural particle sources: smoke from forest fires and the gases emitted by trees that can stick together to form tiny particles.

Study lead author Dr Catherine Scott, from the School of Earth and Environment at Leeds, said: “Natural particles can alter the climate, but they are also strongly controlled by it.

“As the Earth warms, plants release more volatile gases from their leaves – these are the gases that, for example, give pine forests a piney smell. Once in the air these gases can form tiny particles. More particles in the atmosphere reflect away the Sun’s energy, which helps to cool the planet.

“This cooling offsets some of the temperature rise and is known as a negative climate feedback. We can think of forests acting as giant air conditioners slightly reducing the warming due to greenhouse gas emissions.”

Study co-author Dominick Spracklen, Professor of Biosphere-Atmosphere Interactions at Leeds, said: “Overall the response of the climate to an initial warming is to amplify that warming, i.e., a positive feedback.

“This natural negative feedback might act to offset a small amount of warming due to climate change but it is not enough to counteract other strong positive feedbacks in the climate system. This means reductions in greenhouse gas emissions are still required to prevent dangerous levels of global warming.

“Our research highlights the need for these complex interactions to be well represented in climate models. The latest generation of models being used for future climate projections include more detail about the way that the atmosphere and the land surface interact than ever before – but it’s important that we can isolate the role that these processes are playing as the climate evolves.”

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The research paper, “Substantial large-scale feedbacks between natural aerosols and climate“, is published in Nature Geoscience 4th December 2017. (DOI: 10.1038/s41561-017-0020-5). https://www.nature.com/articles/s41561-017-0020-5

Abstract

The terrestrial biosphere is an important source of natural aerosol. Natural aerosol sources alter climate, but are also strongly controlled by climate, leading to the potential for natural aerosol–climate feedbacks. Here we use a global aerosol model to make an assessment of terrestrial natural aerosol–climate feedbacks, constrained by observations of aerosol number. We find that warmer-than-average temperatures are associated with higher-than-average number concentrations of large (>100 nm diameter) particles, particularly during the summer. This relationship is well reproduced by the model and is driven by both meteorological variability and variability in natural aerosol from biogenic and landscape fire sources. We find that the calculated extratropical annual mean aerosol radiative effect (both direct and indirect) is negatively related to the observed global temperature anomaly, and is driven by a positive relationship between temperature and the emission of natural aerosol. The extratropical aerosol–climate feedback is estimated to be −0.14 W m−2 K−1 for landscape fire aerosol, greater than the −0.03 W m−2 K−1 estimated for biogenic secondary organic aerosol. These feedbacks are comparable in magnitude to other biogeochemical feedbacks, highlighting the need for natural aerosol feedbacks to be included in climate simulations.

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95 thoughts on “Another climate feedback found: ‘cooling effect of natural atmospheric particles is greater during warmer years’

  1. They’ve been claiming for years that the overall feedback is positive.
    The problem is that they have yet to scientifically document a single positive feedback.
    In the meantime the number of documented negative feedbacks continues to grow.

    • “The problem is that they have yet to scientifically document a single positive feedback.
      In the meantime the number of documented negative feedbacks continues to grow.”

      Sounds to me like you only count feedbacks “documented” when they are negative. So what do these documenters say?

      ““This natural negative feedback might act to offset a small amount of warming due to climate change but it is not enough to counteract other strong positive feedbacks in the climate system.”

      • As always, Nick sees what he is paid to see.

        The text that you quote fits my definition exactly.
        They declare that the system overall has a positive feedback, but doesn’t bother to document what those feedbacks are.

        If you care to try again and this time actually provide evidence for your claims, you are more than welcome.

      • PS: If the system actually was dominated by positive feedbacks, the climate would be unstable, and any change, no matter how small or from where would cause the climate to run all the way to the rails.
        Since the history of life shows that the climate is remarkably stable, despite fairly large pertubations, that alone demonstrates that the climate is dominated by negative feedbacks.

        I’m still waiting for someone to scientifically demonstrate first any positive feedback, and then the strong ones being claimed by the alarmist crowds.

        Just declaring that water vapor is a positive feedback doesn’t cut it. Actually go out into the field and measure more water vapor in the atmosphere and what happens to that water vapor once it gets into the atmosphere.

      • RW Turner ” the grossly overestimated warming of the models remains a mystery”, it’s should be called Dark Warming. Every field of science needs a “Dark Variable” so it can be matched to observations”.

      • “If the system actually was dominated by positive feedbacks,”………..

        We would have run away global warming…….the set point for this planet is a lot colder…that’s dominate

      • “If you care to try again and this time actually provide evidence for your claims”
        Noting the one-sidedness of your “documenting”. Here we have a purely model-based study. But it shows a negative feedback. Documented. But water vapor faedback, which was obvious enough to Arrhenius, and has been tracked by many since. Positive, so undocumented.

      • Do you have evidence of the positive water vapor feedback, Nick? It is intuitively plausible that warmer air should hold more moisture and seems like the feedback should be obvious. Yet despite several decades of documented warming, actual measurements of total atmospheric water content show a relationship that is at best flat and possibly inverse to temperature. I draw your attention to Kalnay, et al, 1996, “The NCEP/NCAR Reanalysis 40-year Project”, Bull. Amer. Meteor. Soc., 77, 437-471 which if I remember correctly was based on the Earth System Research Laboratory (NOAA) observational data.

      • The problem is that neither positive or negative feedback is a proper characterization of how the climate responds to change. For anything to be considered feedback, or even feedback like, there must be an implicit (and infinite) source of Joules to power the gain and the system must be strictly linear, neither of which is conformed to by the pedantic climate feedback model.

        https://archive.org/details/NetworkAnalysisFeedbackAmplifierDesign

        Chapter 1, page 1, section 1.1 “Introduction”

        Bode is the only reference used by climate feedback papers (Hansen, Schlesinger, Roe) that has anything to do with the concept of feedback. From a circuit perspective, the climate is more properly modelled as an interconnection of passive components with potentially unknown temperature coefficients and with no internal sources of energy (i.e. a passive system).

        Pay special attention to the last sentence of the first paragraph in section 3, where a general acquaintance with feedback circuits is assumed and it was the lack of this understanding that led to Hansen’s original errors which provided the theoretical plausibility for a sensitivity large enough to justify forming the IPCC and which persists to this day.

      • When on a roll, nothing will stop the Great Nick.
        Just claiming that something is obvious is a fools way of trying to get out of providing proof.
        That water is a net positive feedback is often claimed, but has never been actually demonstrated in the real world.

      • “If the feedback were overall positive the historical record of climate would not and could not be what it is.”

        As told me by a Phd palaeogeologist. Whose field is rock dating by proxies…

      • Mike R
        “Do you have evidence of the positive water vapor feedback, Nick?”
        There is no direct evidence of any feedback. It is a mental construct that we use to describe how the atmosphere seems to work. No feasible experiment can “prove” it. Quantification, as in this paper, comes from models.

        But there is certainly evidence (more recent than 1996) that water vapor is increasing with warming. There is, for example, a 2010 paper here by Dessler et al. They sorted the slope of observed specific humidity vs temperature. It’s mostly positive, and short-term, by a lot:

      • So the models to date have NOT been accounting for this important (negative) feedback? Is that point conceded? Kinda makes you wonder how many more natural feedbacks are yet to be discovered and accounted for in this settled branch of absolute certitude.

      • “So the models to date have NOT been accounting for this important (negative) feedback?”
        This feedback was deduced from models. But GCMs don’t deal with feedback directly. People deduce feedbacks from model results.

      • “People deduce feedbacks from model results.”

        No. People deduce feedbacks from model biases, moreover; the very concept of feedback has absolutely no relevance to how the climate system operates.

      • People may “deduce” feedbacks from the models, but to prove them they have to gather real world data.
        In regards to the claim that water vapor is a positive feedback, that assumption is programmed into the models, so it’s hardly surprising that this is the result as well.

      • Nick,
        “…But water vapor faedback, which was obvious enough to Arrhenius, and has been tracked by many since. Positive, so undocumented.”
        No, it is not obvious! So where is the documentation?
        Water is a most peculiar substance (see http://www1.lsbu.ac.uk/water/water_anomalies.html ), documenting how it actually performs in the atmosphere would be a most important endeavor for science. Intuition be damned, show me the evidence.

      • December 4, 2017 at 12:53 pm
        So what do these documenters say?

        Well, Nick S, this is what one of those “documenters” had to say, to wit:

        Study lead author Dr Catherine Scott said:

        We can think of forests acting as giant air conditioners slightly reducing the warming due to greenhouse gas emissions.”

        “HA”, so that “magical” CO2 in forest environments is now deemed responsible for ….. “slightly reducing the warming of the near-earth atmosphere” ……. as well as being responsible for ….. “slightly increasing the warming of the near-earth atmosphere”.

        OH GOOD GRIEF, ….. the green-growing biomass that comprises forest canopies are absorbers of solar energy ….. thus reducing the amount of thermal energy available for “warming” the near surface atmosphere via conduction and radiation.

      • The Dessler & Davis paper starts at the wrong place in the system using the specific humidity(kg water as a % of the mass of the total volume of air and water) and plotted &change anomalies, not the actual amount of water present or its potential effect on the atmosphere. It doesn’t have any specific effect on how the water behaves.
        Engineers use absolute humidity, kg water/kg dry air, measured by dew point. That is the key variable in understanding the behavior of humid air. Absolute humidity or dew point gives a much better way to follow the behavior of water with changes in temperature and pressure. If the temperature falls below the dewpoint part of the water will condense, forming clouds and/or rain and releasing heat.

      • MarkW
        “In regards to the claim that water vapor is a positive feedback, that assumption is programmed into the models”
        Quite untrue. There is nothing about feedback in the models. They solve local equations for momentum, mass and heat transfer, plus radiative. There is nowhere to put information about global feedbacks.

        philo
        “not the actual amount of water present or its potential effect on the atmosphere”
        Specific humidity tells you the amount of water present (in kg/m3, if you know air density). And the radiative effect follows from that.

      • When Nick decides to lie, he goes all out.
        As you well know, the assumption that relative humidity will stay constant when temperatures increase is built into all of the models.
        Real world experiments show that the relationship is nowhere near that simple, but when you have a paycheck to defend …

      • “As you well know, the assumption that relative humidity will stay constant when temperatures increase is built into all of the models.”
        Completely false. I can’t say you lie; you just don’t have a clue, but still make loudmouth assertions.

      • Nick,

        “There is nothing about feedback in the models.”

        On this I can agree with you, however; the models are riddled with assumption, biases and errors. Any of these faults that pushes the models to run hot are accepted by you and your fellow believers due to confirmation bias which is then misinterpreted as the effects of ‘feedback’. The simple fact is that the concept of feedback, per Bode, has absolutely nothing whatsoever to so with how the climate system operates. Bode’s book is the ONLY feedback reference used to support the climate feedback model and yet how his analysis was applied to the climate fails to conform to any of the preconditions for using his analysis. The first missing precondition is strict linearity where the incremental gain (sensitivity) and the average gain must be the same. The second missing precondition is an implied internal source of Joules to power the gain. Both of these are stated in the first 2 paragraphs of Bode’s book and are the only preconditions for using his analysis.

        I suggest that you do some research into the origin of climate feedback, specifically its timing. This was something Hansen fabricated, along with Schlesinger, and which provided the theoretical plausibility for a sensitivity large enough to justify the formation of the IPCC. The reason Hansen fabricated this was in a failed attempt to redeem himself after having been called a lunatic by the Regan and first Bush administration for his chicken little claims of a climate catastrophe caused by CO2 emissions inspired by misinterpreting the correlation between CO2 and temperature seen in the Vostok ice cores as causation.

      • Ice-albedo is not a positive feedback effect, but a simple temperature dependence of the surface reflectance. Above 0C, the reflectivity is that of the land or water below. Below 0C, the reflectivity of the surface is about the same as the reflectivity of clouds, offsetting the albedo effect from clouds at low temperatures.

        Below 0C, clouds only increase surface temperatures by ‘trapping’ heat which is affected by returning absorbed surface emissions back to the surface at a later time. Above 0C, clouds also decrease the incident energy decreasing the surface temperature and the two influences are nearly equal and opposite.

      • When’s the last time somebody did an accounting of cloud cover in the arctic winters? Is low sea ice a product of warm seas inducing more cloud cover in winter? Clouds in summer would also explain why the temps have not exceeded normal, giving us the pattern of global warming mainly manifesting itself as warming in the arctic and sub-antarctic during their resective winters.

      • On the subject of induced clouds, it appears that the higher latitudes are subject to greater CR flux so cloud nucleation should be somewhat enhanced, per the CERN cloud chamber experiment.

    • It makes sense that there are negative feedbacks. This is the norm in nature, otherwise we would by faced with runaway situations, and we wouldn’t have had time to evolve into thinking, reasoning beings who study climate change.

      • It would make sense that there are negative feedbacks if feedback was a relevant property of the climate system. The fact that it isn’t already precludes the possibility of run away and this is the reason why the climate system has been stable for billions of years in the face of incomprehensible change.

        The only reason run away is a theoretical possibility is because the Hansen feedback model assumes an implicit, infinite source of Joules to power the gain, as required by Bode’s feedback amplifier analysis that he misapplied.

        BTW, the Hansen feedback model assumes unit open loop gain (mu==1 per Bode) which means that feedback amplifiers will exhibit finite, stable gain with positive feedback up to, but not including, 100%. Only large values of open loop gain can result in a run away effect.

      • Trebla –
        “It makes sense that there are negative feedbacks. This is the norm in nature, otherwise we would by faced with runaway situations, and we wouldn’t have had time to evolve into thinking, reasoning beings who study climate change.”
        Yes. But – try this –
        “It makes sense that there are negative feedbacks. This is the norm in nature, otherwise we would by faced with runaway situations, and we wouldn’t have had time to evolve into thinking, reasoning beings who seek power and money by being alarmist about claimed climate change.”

        At least as good as your wording, I suggest.
        If a bit more – um – alarmist!

        Auto.

  2. I think it is harder to warm this planet. I do not feel there is any effect that will stop it cooling. Water can change from liquid to vapour. Allowing the world to remove heat from the surface to the upper atmosphere. Once the world starts cooling there is no opposite effect. It will just continue cooling until the conditions change. We should enjoy this breath warm period.

  3. Wow, -0.14 W/M2/ºK,for micrograms of pine smell and smoke per square Km.. What about the 7% more water vapour per degree C warming of ocean surface, which very likely contributes to the atmosphere attempting to form 7% more clouds a hundred or two kilometers downwind, but long before the 7% increased cloud cover can even be detected by satellite…. the resultant cooling causes precipitation… ….which Trenberth’s famous chart puts at 77 Watts/M2 ….or have those scientists read Manabe’s 1964 classic paper, or Ramanthan’s 1978 paper outlining where the potential big unknows are ?

  4. Everyone is worried about warming, but no one seems to know what the optimum temperature is. In the past, higher temperatures were appreciated. What changed?

    • Science … of looking at temperature … and integrating it over time … and basic (like high-school level) radiative transfer / CO₂ / H₂O vapor analysis … pointed to a smoking gun. From there, the long-forgotten ecoterrorists of the 1960s–1970s were rabbled out of their slumber, and took to the airwaves. Liberals – especially huggers – suddenly had a “cause celebré”, something to rally around. The rally started, the young-moms-wanting-to-save-the-world had champions, dads-wanting-to-continue-to-have-favorable-sêx-relations with their spouses chugged a few more beers and were on board. Save a tree, eat a beaver.

      Years pass, prognistications of dire futures, sizzling planets, all life in the equator being parboiled to crispiness, and all equatorial-leaning cities being abandoned … was the norm. Fear – a great inducer of innocent-but-ignorant people being herded like sheep was repeated, repeated, and oft again repeated. Here we are in 2017; the STILL innocent-but-ignorant people have lined up to Save Trees by Eating Beavers. They separate their trash into at least 3 if not 7 or more “streams”. They buy eco-this and eco-that. They proudly grow 1 m² herb gardens as their great (stultifyingly silly) effort to reduce CO₂ exhaling by the armies of 18-wheelers carting the REST of their consumables from field to wholesale aggregator, from there to supermarkets, from there partially to their tables, and just as ironically to the trash bins ‘cuz it ain’t exactly fresh after 10 days on the road.

      But they do their part. They buy (and cajole their neighbors) to “higher enlightenment” living standards. They buy their Priuses, their Volts, their Fiat E’s, their Bolts. They lust for Teslas, they buy rechargeable flashlights (that INEVITABLY are dead in a year before they’re first critically needed!!! Irony alert!!!); they watch the boobtoob, they are peppered with super-duper-calories-are-us fattening food advertising, and the need for endless streams of ridiculously expensive, barely useful modern medicines being hawked by the ABSURD drug industry.

      And they are so, so certain that the righteous way to live is to declare war on nuclear power, to embrace fly-by-night schemes, sweetened and chocolate covered by schmarmy carpet-baggers, to erect enormous wind and solar power plants … which garner billions in investment, but rarely even get to break-even.

      The cockiest suburban roosters have south-facing solar arrays (and leaky roofs), have solar powered cars, golf carts, run-about Mom vehicles. They have their 4 refrigerators and freezers full of all sorts of stuff that’ll inevitably be tossed out in a few years as “too old to consume”. But its all nicely solar powered, so WHO cares?

      I may be a bit dyspepsic this morning, but I truly do reflect on the absurd cinema-of-the-street which is today’s Sheeple Class. All in a line, feeding from the same glory trough of chocolate covered crâhp. And informing ME and YOU that you are a BAD PERSON for not waving the fûqueing flag.

      GoatGuy

    • I’ll take a little WARMING please … my PG+E is Uuuge in the winter here in N.CA … but because I live so close to the Bay … I don’t even HAVE Air Conditioning. I have NO IDEA why PG+E and the CAPUC feel the need to RAPE me and drive me into Energy Poverty!? Why? So they can TAKE my $$$ to “save the planet” (read: line the “green” cronies pockets). HIGH Energy costs are the most REGRESSIVE income tax on the poor and middle class. But that’s how Marxism THRIVES … by grinding down the middle class and making us all DEPENDENT upon a “benevolent” central government.

    • I would optimal temperature is when Canada and Russia have average yearly temperature of 10 C. Right now they are about -4 C.
      So they need +14 C. But + 5 or + 10 C would be better.
      I would guess they aren’t going to get to 0 C before 2100 AD.

  5. It seems to me these particles would operate a lot like clouds. They would both warm through IR absorption and cool through SW blocking.

    So, are they also saying cloud feedback is negative and the IPCC is wrong?

    • The paper declares that there feedback is over all positive.
      Therefore it is proven and doesn’t need to be demonstrated.
      /sarc

    • Alastair,
      Yes. Water vapor is the classic positive feedback. More warmth increases wv in the air, which is a GHG. And the main negative is Planck feedback. The warmer things get, the more they radiate.

      • Yes Nick, but say 1C is 7% more water vapour, call it 2.5 watts worth additional GHE, but if the additional water vapour makes clouds 7% more clouds is .07 x cloud albedo x 263 watts from Trenberth’s chart = 10 watts, not to mention increased precipitation and evaporation…..and voila, a big negative feedback from water vapour condensing to clouds and rain.

      • So Nick, why does it take an El Nino event to actually raise the global temperature here in the 21st century?

      • Speculative? We have instruments. I will not argue that a degree increase at the ocean surface will cause 7% more water vapour in the air immediately above the water (by C-C equation), with positive IR absorption feedback of a few extra watts calculable by HiTran, if you will not argue that hundreds of watts of solar heating are not available for heating whenever a cloud goes over….say weatherstation.uwinnipeg.ca solar intensity any day for example…integrate with a planimeter….

      • As always, Nick assumes what he can’t prove.
        That warmer air is capable of holding more water is a given.
        Whether it does or not is still open to debate.
        Of course what happens to that water vapor once it gets into the atmosphere is also still unknown.
        Real world data suggests that more water vapor in the air results in more clouds which causes water vapor to actually be a negative feedback.
        But don’t tell Nick that, he doesn’t want to know.

      • BTW, I love the way Nick dismisses anything not proven 100% as speculative, and not worth discussing.
        Only speculation that supports his position is permitted.

      • Just some anomalies of water…

        Water material anomalies

        No aqueous solution is ideal.
        D2O and T2O differ significantly from H2O in their physical properties.
        Liquid H2O and D2O differ significantly in their phase behavior.
        H2O and D 2O ices differ significantly in their quantum behavior.
        The mean kinetic energy of water’s hydrogen atoms increases at low temperature (disputed).
        Solutes have varying effects on properties such as density and viscosity.
        The solubilities of non-polar gases in water decrease with temperature to a minimum and then rise.
        The dielectric constant of water and ice are high. [Explanation]
        The relative permittivity shows a temperature maximum. [Explanation]
        The relative permittivity shows a ‘kink’ in its behavior with temperature at 60 °C.
        The imaginary part of the dielectric constant shows a minimum near 20 K.
        Proton and hydroxide ion mobilities are anomalously fast in an electric field.
        The electrical conductivity of water rises to a maximum at about 230 °C.
        The electrical conductivity of water rises considerably with frequency.
        Acidity constants of weak acids show temperature minima.
        X-ray diffraction shows an unusually detailed structure.
        Under high pressure water molecules move further away from each other with increasing pressure; a density-distance paradox.
        Water adsorption may cause negative electrical resistance.

        Water phase anomalies

        Water has an unusually high melting point.
        Water has an unusually high boiling point.
        Water has an unusually high critical point.
        Solid water exists in a wider variety of stable (and metastable) crystal and amorphous structures than other materials.
        The thermal conductivity, shear modulus and transverse sound velocity of ice reduce with increasing pressure.
        The structure of liquid water changes at high pressure.
        Supercooled water has two phases and a second critical point at about -91 °C.
        Liquid water is easily supercooled but glassified with difficulty.
        Liquid water exists at very low temperatures and freezes on heating.
        Liquid water may be easily superheated.
        Hot water may freeze faster than cold water; the Mpemba effect.
        Warm water vibrates longer than cold water.
        Water molecules shrink as the temperature rises and expand as the pressure increases.

        Water density anomalies

        The density of ice increases on heating (up to 70 K).
        Water shrinks on melting.
        Pressure reduces ice’s melting point.
        Liquid water has a high-density that increases on heating (up to 3.984 °C).
        The surface of water is denser than the bulk.
        Pressure reduces the temperature of maximum density.
        There is a minimum in the density of supercooled water.
        Water has a low coefficient of expansion (thermal expansivity).
        Water’s thermal expansivity reduces increasingly (becoming negative) at low temperatures.
        Water’s thermal expansivity increases with increased pressure.
        The number of nearest neighbors increases on melting.
        The number of nearest neighbors increases with temperature.
        Water has unusually low compressibility.
        The compressibility drops as temperature increases up to 46.5 °C.
        There is a maximum in the compressibility-temperature relationship.
        The speed of sound increases with temperature up to 74 °C.
        The speed of sound may show a minimum.
        ‘Fast sound’ is found at high frequencies and shows a discontinuity at higher pressure.
        NMR spin-lattice relaxation time is very small at low temperatures.
        The NMR shift increases to a maximum at low (supercool) temperatures
        The refractive index of water has a maximum value at just below 0 °C.
        The change in volume as liquid changes to gas is very large.

        Water thermodynamic anomalies

        The heat of fusion of water with temperature exhibits a maximum at -17 °C.
        Water has over twice the specific heat capacity of ice or steam.
        The specific heat capacity (CP and CV) is unusually high.
        The specific heat capacity CP has a minimum at 36 °C.
        The specific heat capacity (CP) has a maximum at about -45 °C.
        The specific heat capacity (CP) has a minimum with respect to pressure.
        The heat capacity (CV) has a maximum.
        The high heat of vaporization.
        The high heat of sublimation.
        The high entropy of vaporization.
        The thermal conductivity of water is high and rises to a maximum at about 130 °C.

        Now I hope the climate models have incorporated these attributes where required…

      • Adding to my “we have instruments Nick” of 9:09 Dec 4, I add this from a recent WUWT post by Willis:
        Question by David S December 6, 2017 at 4:40 pm

        Is it possible that clouds cause a net warming?

        Good question. Fortunately, we can measure this from space. The answer is that the net of the two processes you describe, the shortwave and longwave effects, is cooling.

        How much? From the CERES data we have this:

        > getweightedmean(cre_sw)
        [1] -47.12
        > getweightedmean(cre_lw)
        [1] 25.99
        > getweightedmean(cre_net)
        [1] -21.13

        “cre” is the cloud radiative effect, “sw” is shortwave, meaning solar, “lw” is longwave, and “net” is … well … net. The negative net value shows that overall, clouds cool the surface by about 21 W/m2.
        w.e.

  6. The “strong positive feedbacks” they mention are a total fabrication. None have been shown to exist. Sadly, this is the state of “climate science” – it’s the art of making things up, and constantly repeating them as if they were true.

  7. “Study co-author Dominick Spracklen, Professor of Biosphere-Atmosphere Interactions at Leeds, said: “Overall the response of the climate to an initial warming is to amplify that warming, i.e., a positive feedback.”

    Assertions all the way down, and for which there is no compelling observational evidence. Though plenty to the contrary – we are still here.

    • These poor, myopic lab rats can’t comprehend that the air on this planet is in servitude to the water. If you only look at a brief atmospheric record it definitely looks like the atmospheric warming begets more of the same. Looking at the SST records would give a different perspective.

  8. “Overall the response of the climate to an initial warming is to amplify that warming, i.e., a positive feedback.”

    Positive only if one assumes that some warming increases water vapor causing more warming and ignores, or cannot correctly address, the clouds resulting from increased water vapor. Or, one could simply look at atmospheric humidity data accumulated by NOAA and it’s antecedents for the past 70 years or so which shows no increase anyways.

    But that aside, its nice to see somebody looking for non-CO2 global warming (oops, Climate Change) effects.

  9. Off topic, sorry, but I just wanted to point out how strong the central Pacific tradewinds are right now.

    Looks like this La Nina could be moderately strong after all.

  10. “This natural negative feedback might act to offset a small amount of warming due to climate change….”

    But, the title is:
    “Substantial large-scale feedbacks between natural aerosols and climate“

    The title repeats the gargantuan scale of the feedbacks. They are both substantial and large-scale. This is a bump up from previous studies they did that showed substantial but miniscule scale feedbacks.

    The usual “this will not impede the juggernaut of CO2 devastation” seems to be an abundance of caution with CAGW now cancelled by Trump and may end up causing her problems.

  11. Rule 1 of physics is that reaction opposes the action. No positive feedbacks.
    Rule 2 is, if anything contradicts rule 1, it is because of rule 1 itself at some higher level. still no positive feedbacks.
    negative feedbacks all the way down.

    • Not exactly correct.

      Rule no 1 of dynamic systems is that if they demonstrate temporal persistence (they are stable over time) the overall feedback cannot be positive.

      In the case of climate the overall stability is primarily assured by the fourth power radiation: The proposition of the warmists is that ‘positive feedback’ reduces this overall negative feedback somewhat.

      And yet the climate variation post major volcanic eruptions dies not show any of this ‘amplification’: On fact it agrees remarkably well with no ‘positive feedback’ at all. indeed studying the ‘literature’ one notes that this so called ‘positive feedback’;’ only seems to apply to CO2 induced warming and not to warming or cooling induced by solar variation, volcanic eruptions, large scale periodicity in ocean currents etc etc.

  12. MarkW Wrote
    “PS: If the system actually was dominated by positive feedbacks, the climate would be unstable, and any change, no matter how small or from where would cause the climate to run all the way to the rails.”

    This is simple logic. One does not need a science degree to understand this principle. Just observe natural systems that have survived.

    Anyone believing that positive feedbacks dominate negative feedbacks within the climate system over the medium to long term (there is commonly a lag-time) is an idiot IMO. Should this be the case we would not be here.

    M

    • “Anyone believing that positive feedbacks dominate negative feedbacks within the climate system”,/i>
      So who believes that?
      The big stabilizer is Planck feedback. Positive feedback eats into that. But it doesn’t dominate it.

      • Vegetation, rainfall, evaporation, cloud, marine and wind currents (distribution of heat energy around the globe) . These can all function as negative feedbacks. It is not just about what is happening in the upper atmosphere.

        The indisputable proof is that we are still here in spite of natural events with far more impact than a moderate increase in atmospheric CO2. The system has evolved to cope with these evens. Its a no-brainer.

      • Actually I am going to argue against both Nick and Michael here and you only need look at mars to see the fallacy of both arguments. Mars has very little water, no known life and a very very thin atmosphere which has very high levels of CO2. Yet the planet has a stable greenhouse temperature offset of 5 degree. The planet changes temperature by 100 degree between day and night and if there is any instability it would run away one way or another. Nick on the other hand talks about Planck Feedback which is some modelling forcing and yet strangely gives it as a simple number seemingly oblivious to what it actually represents.

        So the challenge to Nick is to convert his number into some physics explaining what his number is. The challenge for Michael is to explain how Mars has a stable greenhouse offset temperature with little water and no known life.

      • “The big stabilizer is Planck feedback. Positive feedback eats into that. But it doesn’t dominate it.”
        another nonsense by Nick.
        Plank feedback is just the reason Earth, seen from space, throw to space as much energy it receives+produces, and has just nothing to do with GHG, GHE, lapse rate, warming or cooling, atmosphere composition, or whatever.
        Positive feedbacks, if they existed, don’t eat into Plank feedback, they even would make it stronger by increasing available heat.

      • “Nick on the other hand talks about Planck Feedback which is some modelling forcing “
        No, it’s basically Newton’s Law of Cooling. It says that if things get hotter, they shed heat faster. For a planet in space, this is reflected in something like the Stefan Boltzmann equation. Maybe not exactly T^4 dependence, but still true that hotter bodies radiate more. That is the fundamental stabilising negative feedback, which if overcome would lead to runaway. Existing positive feedbacks eat into that margin, but don’t create runaway.

      • Woopsie Nick feel in another science huge hole

        https://en.wikipedia.org/wiki/Newton%27s_law_of_cooling

        Finally, in the case of heat transfer by thermal radiation, Newton’s law of cooling is not true.

        So you are claiming it represents a law you are told clearly and absolutely is not true on heat transfer by thermal radiation and this is your version of science :-)

        It helps to understand the laws and what they can be applied to Nick before you start using them.

      • You can’t tell anyone in climate science anything but sometimes when peeps from hard sciences tell you stuff I would read up before making a fool of yourself.

    • Void is a better insulator than anything, better than atmosphere. If atmosphere kept us warm through insulation, the GHE would keep us less warm than the void. It isn’t so.

      • “What is it that keeps us warm again? ”
        thermal inertia, to begin with. example.
        zero enertia, day energy flux J , temperature T1= (J/σ)^0.25 ; night flux 0, T = 0, average temperature T2= (J/σ)^0.25 /2
        infinite inertia, average temperature T3= (J/2/σ)^0.25 = T2 * 2 * (1/2)^0.25 = 1.68 T2
        Atmosphere adds to global thermal inertia because winds transport heat from hot place to cold place.

  13. The “Postive feedback” referred to in this article is just another unsubstantiated claim by the Alarmists.

    What do these guys do when someone says to them “prove it!”?

    Nick didn’t have much to say on the subject. He certainly provided no substantiating evidence for positive feedback so we have to assume he doesn’t have any proof. And neither do the authors of this article. They are just making assertions without evidence, like all Alarmists do.

    • ” This feedback was deduced from models. But GCMs don’t deal with feedback directly. People deduce feedbacks from model results.”

      According to Nick above ‘feedback’ is a knob that modellers twiddle at will.

      • Not at all. I have been pointing out that modellers don’t deal with feedback at all. It is a diagnostic concept that people use to understand how models (and climate) behave.

      • “feedback” is just another name for action-reaction, cause-consequence principle. If “modellers don’t deal with feedback at all”, it means that they don’t deal with physics, so it is quite funny that someone one preach trust in those model would write that.
        Feedback is not a diagnostic concept. GHE is.

      • Yes look above he actually claimed it is basically “Newton’s Law of Cooling” not realizing heat transfer by thermal radiation is a quantum process and doesn’t obey stupid classical laws. The funny part is under the proper QM laws the feedback number they are modelling has many many inputs and not even guaranteed to be negative. I suspect Nick is just another activist well out of his depth.

      • Nick,

        when the hole gets too deep, one should stop digging.

        one feedback analogy would be that your hole is so deep that 20% of the dirt that you try to throw out of the hole falls back on your head.

        i don’t know if this a positive or negative feedback….

  14. I used to fly up and down the east coast of Australia for work. During drought years there was a pretty well permanent dust haze over the inland, and it was clear on the seaboard side.

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