Climatologist’s Cloud Confusion Continues: Catastrophists Claims Completely Confounded.

Posted: March 15, 2020 by tallbloke in Analysis, climate, Clouds, modelling

For decades we’ve been told that net cloud radiative forcing is positive. This means that the the amount by which clouds cool the surface, by reflecting solar radiation back to space, is outweighed by the amount that clouds warm the surface, by re-radiating surface emitted IR back towards the ground. So cloud increase equals warmer surface See e.g IPCC AR5 on the subject:

The net radiative feedback is the sum of the warming and cooling feedbacks; the executive summary states “The sign of the net radiative feedback due to all cloud types is less certain but likely positive. Uncertainty in the sign and magnitude of the cloud feedback is due primarily to continuing uncertainty in the impact of warming on low clouds.” They estimate the cloud feedback from all cloud types to be +0.6 W/m2°C (with an uncertainty band of −0.2 to +2.0), and continue, “All global models continue to produce a near-zero to moderately strong positive net cloud feedback.”[18]

The closely related effective climate sensitivity has increased substantially in the latest generation of global climate models. Differences in the physical representation of clouds in models drive this enhanced sensitivity relative to the previous generation of models.[20]

But now a new article on NASA’s climate website has thrown this into doubt. It tells us:

◆Understanding how greenhouse gases will affect clouds is crucial to forecasting climate change. But current computer climate models can’t handle the high resolution needed to simulate cloud dynamics worldwide.

◆A recent study suggests that if greenhouse gases raise the atmosphere’s temperature enough, stratocumulus clouds could disappear, causing a large spike in global temperature.

◆JPL is partnering with Caltech, MIT and the Naval Postgraduate School to build a new climate model that can take full advantage of Earth-observing satellites, with thousands of sub-models capable of simulating the dynamics of clouds and other small-scale phenomena.

That second point tells us that this new climate model has cloud radiative forcing as net negative, not positive. If cloud decreases, letting more sunlight to the surface, that will cause surface temperature to rise.

Watch the pea carefully here. Climate models have only been able to get any exciting amounts of global warming by assuming a large and positive water vapour feedback. Warming caused by extra CO2 causes more evaporation and increased amounts of airbourne water vapour, a more potent and prevalent ‘greenhouse gas’.

If global warming caused by more CO2 and WV feedback is going to raise the temperature to the point where clouds disappear, allowing the Sun to warm the surface making things even hotter, then there will be more evaporation of water from the surface. But it won’t be forming clouds apparently. Somehow there must be a switchover point where positive cloud radiative forcing becomes negative? It all seems very confused.

I think the modelers have painted themselves into a corner with positive cloud radiative feedback and are now trying to escape with this ‘new model’. The fundamental problem is that they think extra CO2 has caused the warming and cloud reduction as measured by satellites over the last 40 years, and are now trying to reconcile this.

But what if it was the reduction in cloud which caused the warming, rather than the other way round? After all, that’s what they’re now proposing as the outcome of reduced cloud, so why wouldn’t it have been the cause of the warming in the first place?

Ned Nikolov and Karl Zeller are writing up a new paper on cloud albedo and climate which will explore that possibility. Here’s a sneak preview:

See more at Ned Nikolov’s twitter moments.

  1. tallbloke says:

  2. […] über Climatologist’s Cloud Confusion Continues: Catastrophists Claims Completely Confounded. — Ta… […]

  3. Ron Clutz says:

    As you know, Martin Wild leads the Global Brightening and Dimming research center at ETH Zurich. His latest paper abstract:

    “The amount of solar (shortwave) radiation that reaches the Earth’s surface underwent substantial variations over recent decades. Since the 1950s, surface shortwave radiation gradually decreased at widespread locations. In Europe, this so-called surface dimming continued until the late 1980s, when surface brightening set in and surface shortwave radiation increased again. In China, the dimming levelled off in the 1980s, but did not turn into brightening until 2005.

    Changes in clouds and aerosol are the prime potential causes for the phenomenon, but the scientific community has not yet reached a consensus about the relative role of the different potential forcing agents. Here we bring together co-located long-term observational data from surface and space to study decadal changes of the shortwave energy balance in Europe and China from 1985 to 2015.

    Within this observation-based framework, we show that an increasing net shortwave radiation at the top of the atmosphere and a decreasing atmospheric shortwave absorption each contribute roughly half of the observed brightening trends in Europe. For China, we find that the continued dimming until 2005 and the subsequent brightening occurred despite opposing trends in the top-of-the-atmosphere net shortwave radiation.

    This shows that changes in atmospheric shortwave absorption are a major driver of European brightening and the dominant cause for the Chinese surface trends. Although the observed variations cannot be attributed unambiguously, we discuss potential causes for the observed changes.

    Paper is here:

  4. Ron Clutz says:

    Background on Wild and ETH Zurich Global Energy Balance Archive is at:

  5. tallbloke says:

    Thanks Ron, good resource.

  6. oldbrew says:

    Differences Between North- and South-Facing Slopes

    The face a slope presents to the sun – north or south – plays a role in the local climate created on it. This “microclimate” helps determine the types of plants that colonize the slope and influences which animals are drawn to the area seeking their preferred foods and suitable shelter. The basic difference between north- and south-facing slopes – the relative amount and intensity of sunlight they receive – leads to profound ecological differences, similar (but reversed) in the Northern and Southern Hemisphere.

    What/where is the cloud role?

  7. ivan says:

    In other words they still don’t know very much about how the atmosphere works yet they are using some guesses to extort billions out of the public purse to prop up their lifestyle.

  8. tallbloke says:

    Ivan: Pretty much, yeah.

    OB: The cloud role (and latitude) has much to do with the average furriness of the critters favouring either slope.

  9. docsiders says:

    Real Scientists don’t twist and turn in the wind to resist obvious indications provided by data.

    Then NASA doubles down with a totally illogical (childish, actually) “shell game” explanation that points toward horrifying warming caused by the ERASURE of high levels of LWIR cloud reflection…leaving only the lower level direct radiation…it was jaw droppingly obvious.

  10. tallbloke says:

  11. erl happ says:

    The warmth of the northern hemisphere in July by comparison with the southern hemisphere in January is due to cloud loss.

    In July, solar irradiation is 6% less due to the orbital factor. But due to the loss of the cloud in the middle of the year driven by radiation from the vast continents of the northern hemisphere, average temperature is about 6 degrees C greater than that of the Southern hemisphere in January. Take away the cloud and the surface warms.

    So, greenhouse theory relating to forcing of back radiation by cloud is just plain wrong.

    The cloud affected is very likely cirrus. Ice cloud yields greater reflectivity per gram of water vapour.

    Enhanced OLR and the presence of ozone above 500 hPa is a recipe for cloud loss because ozone
    amplifies the temperature response.

  12. E.M.Smith says:

    Every time a cloud, any cloud at any height, gets between my skin and the sun, I feel colder.

    As this always happens, my conclusion is that clouds block sunshine and cool me .

    After sundown, clouds or not, it gets colder the longer I wait. My conclusion us that clouds DO NOT WARM.

    Cloudy nights sometimes cool more slowly than crisp cold nights. They still cool. My conclusion is sometimes clouds can block a little cooling earth radiation.

    As the sun provides vastly more radiant heat than the earth, clouds must net cool as they block more inbound solar radiation than outbound Earth radiation.

  13. Phoenix44 says:

    Of note is the fallacy that modelling in more detail will “solve” the problem. If you don’t understand the basic physics, the model will not help you, even if you go into greater and greater detail. As my old boss used to say – spurious accuracy.

    What we have here is a clear admission that the climate scientists do not know how clouds work. They don’t know how and why the form and they don’t know what effect they have on temperature. What that means is that they do not know whether temperature increases over the last fifty years are caused by clouds and nit CO2.

  14. oldbrew says:

    The NASA energy budget diagram at Wikipedia has back radiation over twice as powerful at the surface as incoming solar radiation. Funny how snow melt prefers to occur on the sun-facing side of slopes 🤔

    = = =
    For amusement only…

    The ‘climate doomers’ preparing for society to fall apart
    By Jack Hunter
    BBC News
    8 hours ago

    She thinks there will be a day when the electricity is cut off, so she is learning to recite poems by heart, in case she finds herself alone, with no internet or possessions.

    Prof M Mann calls it ‘crypto-denialism’.

  15. cognog2 says:

    Currently the Groupthink is concentrated on matters of radiation for explanations. However there are other factors which need consideration if an understanding of cloud behaviour is required. The Hydro Cycle actually operates as a Rankine Cycle and there is a great deal of knowledge on this mechanism which could be usefully employed. For instance we know that for every kilogram of water evaporated at the surface, some 694 Watthrs of energy is pumped up into the clouds and beyond to space for dissipation. This taking place irrespective of radiation energy movements. Unfortunately the science driving this does not fit in with the Groupthink mindset which, to me, explains why there is confusion on the part played by clouds in climate behaviour.
    If this science does get included in the calculations then it could well be found that water provides a net negative feedback to the Greenhouse Effect. Sadly, as this result would be considered inconvenient i suspect it will get suppressed for political reasons.

  16. Ron Clutz says:

    Those energy balance diagrams make the mistake of treating SW Wm2 the same as LW Wm2 by adding or subtracting them from each other. According to Planck’s constant, the energy flow varies with the temperature of the emitting body.

    A post discussing this is

  17. tom0mason says:

    oldbrew @ March 16, 2020 at 8:43 am

    The Earth’s energy budget is not a finite thing! Its an ever changing continuum of an open system, an open system that depend on many internal and external variables.
    At any moment energy into the system DOES NOT equal energy out!
    As the weather and climate is at it’s basic a chaotic process, and small changes in a chaotic system can precipitate large down the road. ALL the figures for ‘Energy Balance’ should be seen (at best) as guesses with huge error bar values. All too often THAT diagram is taken as absolute with measured values (from the past) but it is not.
    Energy flows are not smooth and even, ‘energy in’ is to some degree ‘lumpy’, ‘energy out’ is often very ‘lumpy’. If they didn’t then climatic periods of cool and warm would not exist. These energy flows do not have to balance over any arbitrary time period. They only have to balance ultimately, i.e. when the process ends!

    It is well known and studied that nature can dramatically change the flows of the weather (and climate), so this amount of change (NASA diagram above)in the last few years should vary climate somewhat. Changes in plants and forests can have large impacts on the climate.
    Also the last few years has seen quite a few volcanic eruptions, and these too have an effect on the weather and the climate (more lumpiness in energy flows).

    The sun’s activity changes,
    Vegetation extent changes, (and so animal populations change),
    Ice cover changes,
    Cloud cover changes,
    Ocean currents …
    etc., etc.,

    The Earth’s ‘Energy Balance’ is a highly variable process not a fixed calculation. Changing as it does from day to day, month to month, season to season, year to year. Trenberth and the UN-IPCC is wrong, that model is wrong!

    Nature always SEEKS equilibrium, often it can NOT effect such a result.

  18. oldbrew says:

    To be clear, I wasn’t promoting the NASA cartoon as the truth. But it exists and people look at it.

    My question is: how is it that all that *alleged* back radiation can’t melt the snow on the side of a mountain not facing the sun, while a *supposedly* much smaller amount of power from the sun has done the job on the other side?
    – – –
    NASA tries to gloss over the increase in Mount Kilimanjaro July/August snow cover in 2019 compared to 2013, by showing data only up to 2016, but the photos give the game away. Data shows hardly any loss between 2007 and 2016 either.

  19. Russ Wood says:

    A few years ago, ‘Tony Heller’ (of told an anecdote of when he was working with a Cray supercomputer. A postgrad student had won some time on the machine (sort of like gold at the time) and was trying to model a cloud. He ran out of computer time before he had any success. It seems that clouds are kinda complex!

  20. oldbrew says:

    Crocodiles in the Arctic by 2001? Place your bets.

    If this is what happened 50 million years ago, Schneider said, the surge of heat from the loss of the clouds, on top of the warming from the increase in greenhouse gases, could have raised temperatures enough to make the Arctic suitable for crocodiles. If we continue releasing greenhouse gases at our current rate, he added, we could reach that point again somewhere around the beginning of the next century.

  21. oldbrew says:

    Science Focus asks: If global warming increases rainfall, could the extra clouds block sunlight and help cool the Earth?

    Clouds are notoriously difficult to predict with certainty, but most climate models agree that changes in clouds will have the net effect of amplifying rising temperatures.
    – – –
    most climate models agree — well, there’s your problem 🙄