How clouds hold the key to global warming 

Posted: November 4, 2020 by oldbrew in climate, Clouds, modelling, radiative theory, Uncertainty
Tags: ,

Cumuliform cloudscape over Swifts Creek, Australia
[image credit: Wikipedia]

Do we see a chicken and egg conundrum when reading that there’s ‘a project to study how low clouds respond to climate change’? Accurate data on clouds in general is sparse, making any assertions about future climate questionable.
– – –
One of the biggest weaknesses in computer climate models – the very models whose predictions underlie proposed political action on human CO2 emissions – is the representation of clouds and their response to global warming.

The deficiencies in computer simulations of clouds are acknowledged even by climate modelers, says Science under attack (via The GWPF).

Yet cloud behavior is key to whether future warming is a serious problem or not.

Uncertainty about clouds is why there’s such a wide range of future global temperatures predicted by computer models, once CO2 reaches twice its 1850 level: from a relatively mild 1.5 degrees Celsius (2.7 degrees Fahrenheit) to an alarming 4.5 degrees Celsius (8.1 degrees Fahrenheit). Current warming, according to NASA, is close to 1 degree Celsius (1.8 degrees Fahrenheit).

Clouds can both cool and warm the planet. Low-level clouds such as cumulus and stratus clouds are thick enough to reflect 30-60% of the sun’s radiation that strikes them back into space, so they act like a parasol and cool the earth’s surface.

High-level clouds such as cirrus clouds, on the other hand, are thinner and allow most of the sun’s radiation to penetrate, but also act as a blanket preventing the escape of reradiated heat to space and thus warm the earth.

Warming can result from either a reduction in low clouds, or an increase in high clouds, or both.

Our inability to model clouds satisfactorily is partly because we just don’t know much about their inner workings either during a cloud’s formation, or when it rains, or when a cloud is absorbing or radiating heat. So a lot of adjustable parameters are needed to describe them.

It’s partly also because actual clouds are much smaller than the minimum grid scale in supercomputers, by as much as several hundred or even a thousand times. For that reason, clouds are represented in computer models by average values of size, altitude, number and geographic location.

Most climate models predict that low cloud cover will decrease as the planet heats up, but this is by no means certain and meaningful observational evidence for clouds is sparse.

To remedy the shortcoming, a researcher at Columbia University’s Earth Institutehas embarked on a project to study how low clouds respond to climate change, especially in the tropics which receive the most sunlight and where low clouds are extensive.

Continued here.

  1. Chaswarnertoo says:

    And global cooling….😇

  2. Phoenix44 says:

    If you can’t model a significant part of the climate you can’t model the climate. Its axiomatic. As I never get tired of saying, any model of anything can only make accurate predictions if it gets starting conditions right. We cannot put a man on the Moon if we get where the Moon is when we start wrong. If the models cannot forecast clouds correctly then they cannot get starting conditions right because they cannot know why there are the existing clouds. So every model will.start to diverge from reality as soon as it us run and that divergence will increase (unless you run enough enough times when some will converge purely through randomness).

    Climate models are simply not capable of doing what they are used for. They cannot, except through luck, predict the future.

  3. jeremyp99 says:

    NASA bod quite clear their modelling of clouds is worse than useless

    “NASA has conceded that climate models lack the precision required to make climate projections due to the inability to accurately model clouds.

    Clouds have the capacity to dramatically influence climate changes in both radiative longwave (the “greenhouse effect”) and shortwave.”

  4. erl happ says:

    The notion that high cloud, cirrus, is different in its reflective properties is demonstrably false. When temperature at the surface increases it relates to an increase in geopotential height at all elevations, including the elevations where cirrus exists. In fact the increase in the temperature in the cirrus layer is usually a multiple of that at the surface. with the surface increase lagging the increase aloft.

  5. Gamecock says:

    ‘computer climate models’

    They should be enjoined from using the word ‘model.’

  6. oldbrew says:

    Met Office: How we measure sunshine and radiation

    For a great many years the only instrument for measuring sunshine duration was the Campbell-Stokes sunshine recorder. The original instrument was invented by Campbell in 1858 but the later card-holding version was a development by Stokes in 1879.

    Most of the climate record was collected using this instrument and it continues in use today at many non-automated climate stations. A glass sphere focuses the sun’s direct radiation on a graduated card and the length of the burn trace on the card corresponds to the duration of sunshine.

    This method of measurement significantly overestimates sunshine duration on days when the sun is frequently shaded by passing clouds. [bold added]

  7. stpaulchuck says:

    and where’s the references to to cosmic rays and cloud stimulation?? and solar minimum and maximum solar winds and filtering of the cosmic rays??

    That “study” is typical bias confirmation seeking. The assumption is that warming is causing cloud cover changes (and it may well do so) while ignoring that cloud cover changes are causing at least some some of the climate heating/cooling. “Humans bad! Mother Gaia good!”

  8. oldbrew says:

    The different day and night effects of clouds add another layer of complexity.

  9. Paul Vaughan says:

    IT’shells Linear Orwellian Signature of Isolated 1 Variable

    “Clouds” — the way the term is being used — are not a “key”.

    Take 1 local example:

    Summer cloud means cooler.
    Winter cloud means MUCH, MUCH warmer.

    That is for 1 location.

    For however few sensible people there are (decades-long stupid partisan arguments aside), coupled bundles integrate holistically.

    Materials science (what they call the engineering field) gives landscapes of phase relations. Orwell enthusiasts like a linear function of one variable at a time — always “considered” in isolation.

    Door will: IC loud control knob.

  10. tom0mason says:

    Climate models?
    In all the decades of running these useless pieces of technology they have not come close to forecasting the climate.
    Useless with clouds, useless with precipitation, can not predict snow events, do not properly track ocean current effects, miscalculate solar effects, totally misunderstands the chaos inherent in climate interactions, etc., etc. Even their very basics, the so called ‘basic science’ in them has to be manipulated to get an output that seems close to a reality.
    ‘Climate models’? A work creation scheme for those people who are miseducated beyond their ability to hold down proper jobs!

  11. oldbrew says:

    ‘The latest generation of computer models, known as CMIP6, predicts an even greater – and potentially deadly – range of future warming than earlier models. This is largely because the models find that low clouds would thin out, and many would not form at all, in a hotter world. The result would be even stronger positive cloud feedback and additional warming. However, as many of the models are unable to accurately simulate actual temperatures in recent decades, their predictions about clouds are suspect.’
    – – –
    Models were never going to be an accurate guide to the future. However, constant predictions of warming well in excess of what is observed, tell their own story.

  12. erl happ says:

    Reply to Paul Vaughan, I endorse what you say. The temperature of the air is determined by where it comes from. In winter, warm air will be moist, cloudy and precipitating. Cold air will be dry, there will be little cloud and its come from a cold place.

    It follows that the temperature of all points between the warmest and the coldest places is dependent in the first instance on the planetary winds. If you are talking climate change you are talking change in the planetary winds….and the ocean currents.

  13. ivan says:

    It is interesting how they still talk about climate models, plural, especially considering the fact that in 2014 they were so emphatic that ‘the science is settled’. If that were the case then there would, by now, be a single climate model that allows for daily forecasting anywhere in the world for any day in the future.

    Since there isn’t a single model that allows forecasting/prediction anywhere with any accuracy I think any intelligent person can conclude that the climate models don’t work and don’t model the climate at all.

    I can’t help wondering how they try to mathematically describe clouds that change constantly in density and position and are never the same at the same time on different days. Then there is temperature, to get any accuracy they need to know the temperature on a fine grid of about 10 metres (example, if I walk down my road I drop about 30 metres and 2 degree C in the evenings), that grid might be expanded to 1 km but shouldn’t any greater and the temperature for the sections og the grid should be real readings taken at the same time. If they can’t reach those standards they should give up on trying to model the climate since they will never be able to. The only thing climate modelling has going for it is that it keeps some wackademics employed.

  14. Paul Vaughan says:

    Erl, I suspect few of us will live long enough to see a mature climate science grounded simply in number theory not yet grasped by luminaries today.

  15. oldbrew says:

    Discovering convection?

    NOVEMBER 4, 2020
    Convection-permitting modelling improves simulated precipitation over Tibetan Plateau
    — Chinese Academy of Sciences

    Convection-permitting models (CPMs), with horizontal-grid spacing of less than five km, are constructed to partially resolve (rather than parameterize) convective heat and moisture transport. They offer a path towards fundamental advances in our understanding of factors influencing clouds and precipitation, and have become important tools for climate research.

  16. tom0mason says:

    Here is a static rendition of a cloud image using fractals. It’s only 2D and unmoving but it could be a start.
    IMHO the climate is like a vast, and slowly modifying, fractal pattern of near similar, reoccurring themes and rhythms.

  17. oldbrew says:

    Sound the alarm – part 499…

    Mixed-phase clouds slow down global warming, but only up to a certain point

    As the ice in the clouds melts into droplets, they reflect more sunlight. But in the end there is no more ice left to melt.
    – – –
    The linear climate model strikes again.
    = = =
    Study: Polar stratospheric clouds initiated by mountain waves in a global chemistry–climate model: a missing piece in fully modelling polar stratospheric ozone depletion.

    An important source of polar stratospheric clouds (PSCs), which play a crucial role in controlling polar stratospheric ozone depletion, is the temperature fluctuations induced by mountain waves. These enable stratospheric temperatures to fall below the threshold value for PSC formation in regions of negative temperature perturbations or cooling phases induced by the waves even if the synoptic-scale temperatures are too high. However, this formation mechanism is usually missing in global chemistry–climate models because these temperature fluctuations are neither resolved nor parameterised. [bold added]

  18. Paul Vaughan says:

    tom0mason, key door fall O-win sentUNs “all”:

    Rational functions of j are modular, and in fact give all modular functions.

    All’s One O at what curry US sly’s UN”surprising” hear:

    “[…] it also has surprising connections to the symmetries of the Monster group (this connection is referred to as monstrous moonshine).”

    “I can still recall the time we tied to break con Thor[]O2 THEO[]airsID” — The Doors

    IT’sure PRys! PR Joe Act outside door[shh!]rink cove^red play yen hawk key.

  19. Paul Vaughan says:

    Mods: “junk!sure” 162’s link in.the.fill tour.

  20. NeilC says:

    The most important aspect of clouds is the humidity within clouds. Considering the atmosphere is 50% saturated. I suggest it is the level water vapour saturation which causes the biggest temperature increase/decreases.

  21. oldbrew says:

    NOVEMBER 5, 2020
    Past is key to predicting future climate, scientists say

    “We find that many models perform very well with historic climates, but not so well with climates from the Earth’s geological past,” Tierney said.

    One reason for the discrepancies are differences in how the models compute the effects of clouds, which is one of the great challenges in climate modeling, Tierney said. Such differences cause different models to diverge from each other in terms of what climate scientists refer to as climate sensitivity: a measure of how strongly the Earth’s climate responds to a doubling of greenhouse gas emissions.

    Several of the latest generation models that are being used for the next report by the Intergovernmental Panel on Climate Change, or IPCC, have a higher climate sensitivity than previous iterations, Tierney explained.

    “This means that if you double carbon dioxide emissions, they produce more global warming than their previous counterparts, so the question is: How much confidence do we have in these very sensitive new models? [bold added]
    – – –
    And the answer from here is: none. Fearmongering requires ever more scary scenarios, like a Ponzi scheme needs ever more punters. But the escalation can’t go on for ever, as its own absurdity will catch up with it in the end.

  22. cognog2 says:

    This problem for the IPCC et al will not be resolved until the current group mindset of trying to explain everything by observing radiation data is put to one side and the basic thermodynamics of the Hydro Cycle brought into the equations. There is a wealth of knowledge, information and experience here just waiting to be utilised; but is currently being ignored as it operates outside the radiation box and deals with actual movements and changes in energy in the climate taking place irrespective of radiation matters.
    A simple look at the steam tables reveals that for every kilogram of water evaporated from the surface some 694 Watthrs. of energy gets pumped up into atmosphere and beyond for dissipation before returning to earth as rain, snow or ice. This done alongside radiation and independently.
    By ignoring this aspect it is of no surprise that the IPCC et al are at a loss to understand the clouds which are just a visible element of the thermodynamics involved in the Hydro Cycle.

  23. tom0mason says:

    Interesting that the differential temperature from equator to poles have were falling from 1948 to 2007 as per this NCAR-NCEP reanalysis daily data (t2m, downloaded from KNMI) at
    This should affect the cloud formation, should it not?
    Here’s an old source of data up to 2010 for a similar period showing global clouds.
    I can not find any source of more up to date information, I would have thought this site — or should have it but apparently not.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s