Climate Models Get Clouds Wrong – They Cool

It would be funny if it weren’t so sad…

Pro-Catastrophic Global Warming papers trumpet falsehoods with vigor and certainty. Stating as confirmed absolute fact, trivial and obviously wrong speculation.

Here a paper states a clear truth anyone in any warm to tropical area has directly experienced, and couches it in all sorts of hem-haw words. The ‘maybes’ and the ‘could bes’ abound.

Anyone who has been to Disney World, or anywhere else in a semi-tropical to tropical area, will be familiar with the Afternoon Cooling Rain. Happens every day all summer long (and into the “shoulder seasons” too). Winters are dryer.

The sun rises. The land starts to warm up. Plants, ponds and puddles all start to evaporate water. The humidity rises and it gets HOT. Then all that humidity rises into the air. Clouds form and roll in. The shade helps with the direct solar heat, but it is still a bit too warm and muggy. Then the rains come.

Just when the rain starts has a seasonal variation to it. I spent about 3 years all told working in an office building with a view out a wall of windows. The Contractor Bullpen. Folks watched the windows on and off all day long. Why? Because if it was going to be a torrential downpour at noon, you would not want to be walking to your car for a lunch off campus, but would head for the cafeteria. Were the deluge coming at 4:30 pm, don’t wait until 5 pm to head home. After a while, you get in sync with nature.

When the rains come at noon, they are over before it is time to go home. Lunch in, work later. When the rains come just before 5, arrive at work early and leave early, lunch out is OK. As the summer arrives and warmth increases, the rains come earlier. As the season heads into fall and winter, the rains move to later in the day and eventually stop.

The really surprising thing is just how much the arrival of the clouds and afternoon rain cools everything down. Sometimes even to the point of hail on the ground. Nothing like a dump of many tons of ice pellets to cool down the surface temperature.

After a while, you start to anticipate the cooling relief of the “afternoon clouds and rain”. Waiting for it. Hoping it will “dump and go” in that mid-afternoon window just before you try to get to the far side of the parking lot, and your car, without being drenched in sweat from a walk though the hot muggy pre-rain air. Many times I worked a little late as much to get a cooler walk to the car as to avoid walking in a drenching downpour.

The interesting thing is that anyone who lived there any length of time knew about this. It is just part of life. EVERYONE who lives there knows “The clouds and rain cools things off”. Somewhere in the ’90s I was at Disney World with the family. We were in Epcot just after noon. It was hot and muggy. Then the afternoon rains rolled in. A LOT of tourists headed into buildings and to the exit, thinking their Disney day was over as it was raining. We ducked into a shop too. They sold plastic poncho rain covers for a couple of bucks. I muttered something about the rain as we talked about leaving or staying. The clerk, clearly a local, explained that in 2 hours or so the rain would be over and it would be much nicer. Cooler and yet still sunny. We spent about 2 hours looking at indoor exhibits and such, then the day blossomed into a very nice, cooler and less humid, afternoon and evening.

I’ve written about this effect before. and for example.

Mega tons of water vapor in clouds means megatons of cooling refrigerant evaporated from the surface, carried high to the top of the tropopause where it condenses and often freezes (giving up both heat of vaporization and heat of fusion to be radiated to space) then the liquid or solid plunges to the surface bringing that cold mass back down and cooling things off.

At the same time, the formation of those clouds shuts down the arrival of solar radiative energy and heat at the surface. It both stops the arrival of new energy and transports the existing accumulation to the tropopause for radiating out into space. It is a fundamental limit on surface heating. That is why wet places, like oceans and the tropics, are always cooler than the hottest deserts. Why you don’t get a record 125 F or 135 F in the tropics, but only in deserts lacking this cooling cycle.

At about 84 F, large water surfaces are moving so much water vapor and heat skyward that you get various kinds of cyclonic storms. From the (aptly named) Tropical Storm all the way to Hurricanes, Cyclones, and Typhoons. All the same thing, just different names in different parts of the world. These move quantities of heat measured in “Atom Bombs” of size. Taking it to the top of the sky and spreading it out over hundreds of miles of diameter to effectively radiate it to space. The Locals in Florida knew this and would cheer a “near miss” of a tropical storm for the cooling it would leave in its wake.

So, OK, academia is tepidly recognizing that maybe, possibly, what everyone knows might, in some small way, actually happen… Yeah, that’s news. Did none of these folks ever take a vacation in Florida or Hawaii or anywhere in the tropics? Or is it “willful blindness” for grant money? I’ll put my $Money on $The $Money.

This is the Humanities Translation write up of the paper cited below. For those who don’t like reading science papers directly. The basic points? Recent climate models are running hotter than ever (to keep the scare going and the grant money flowing) largely due to getting clouds wrong and attributing more warming to a cloudier word rather than recognizing they are a hard limit on max heating anywhere with water: which is 70% of the planet as oceans, more as lakes and streams (and ponds and puddle and…), along with the huge areas of tropical plants all doing transpiration. (Not to mention the corn in Iowa…) I’ve bolded some bits.

Warmer Clouds, Cooler Planet
New paper: precipitation-related “feedback” cycle means models may overestimate warming

Today’s climate models are showing more warmth than their predecessors
, forecasting an even hotter future for the same rise in atmospheric carbon dioxide. But a paper published this week highlights how models may err on the side of too much warming: Earth’s warming clouds cool the surface more than anticipated, the German-led team reported in Nature Climate Change.

“Our work shows that the increase in climate sensitivity from the last generation of climate models should be taken with a huge grain of salt,” said CIRES Fellow Jennifer Kay, an associate professor of atmospheric and oceanic sciences at CU Boulder and co-author on the paper.

She and her colleagues modified a model used in international climate assessments like the IPCC to better understand the impact that warmer clouds have on climate.

Warmer clouds differ from their colder, icier counterparts in two main ways: (1) they are more reflective, sending more heat back into space; and (2) they don’t precipitate as easily, remaining in the atmosphere for longer periods of time. But climate models used in the IPCC don’t yet account for these differences, introducing model biases that could impact projections of future climate.

“Climate models do not represent this precipitation efficiency difference between warm and cold clouds, so they underestimate the associated negative feedback with a transition from cold clouds to warm clouds,” Kay said.

Cold clouds? Warm clouds? Cloud temperatures change with time and altitude. Why not talk about that? The Thunderhead that is 100 F at the surface over an Iowa corn field is making hail and ice at 40,000 Feet. All in the same convective cell.

OK, ok, take a “may maybe might” tiny little win when you can. But really, the confounding of heat and temperature here is a travesty. A tropical thunderhead is absorbing heat at the surface at 85 F to 105 F and DUMPING that heat at 32 F at the top. Seems counter intuitive and somehow wrong, but that is because most folks confuse heat (energy flow) and temperature (average velocity of an atom or molecule). When water evaporates it absorbs energy to turn into a gas all while the temperature stays constant or drops a little. When water condenses at the top of the cloud it gives up that energy. It also often gives up the “heat of fusion” as it freezes to ice. Yes, dumping heat at 32 F into the even colder stratosphere and space.

They need to get this mechanism right and stop talking about “warm” vs “cold” clouds. Talk about the heat flow in the formation of clouds and rain and the temperature and HEAT FLOW variations through the clouds. Oh Well… Maybe next cycle of climate models… /sarc;

The actual paper is here:

Published: 03 June 2021

An underestimated negative cloud feedback from cloud lifetime changes

Johannes Mülmenstädt, Marc Salzmann, Jennifer E. Kay, Mark D. Zelinka, Po-Lun Ma, Christine Nam, Jan Kretzschmar, Sabine Hörnig & Johannes Quaas
Nature Climate Change volume 11, pages508–513 (2021)


As the atmosphere warms, part of the cloud population shifts from ice and mixed-phase (‘cold’) to liquid (‘warm’) clouds.
Because warm clouds are more reflective and longer-lived, this phase change reduces the solar flux absorbed by the Earth and constitutes a negative radiative feedback. This cooling feedback is weaker in the sixth phase of the Coupled Model Intercomparison Project (CMIP6) than in the fifth phase (CMIP5), contributing to greater greenhouse warming. Although this change is often attributed to improvements in the simulated cloud phase, another model bias persists: warm clouds precipitate too readily, potentially leading to underestimated negative lifetime feedbacks. In this study we modified a climate model to better simulate warm-rain probability and found that it exhibits a cloud lifetime feedback nearly three times larger than the default model. This suggests that model errors in cloud-precipitation processes may bias cloud feedbacks by as much as the CMIP5-to-CMIP6 climate sensitivity difference. Reliable climate model projections therefore require improved cloud process realism guided by process-oriented observations and observational constraints.

Um, IMHO, as the “atmosphere warms” you will just get more evaporation at the surface, faster convection (as water vapor is 18 mass units and air is about 30 per unit volume), higher cloud heights with icier tops and more dense tropical rains and cooling hail formation.

This is Willis’s Tropical Cloud limit theory too. It is also known by a few other names. Tropical Thermostat and more. It is also what anyone living in a warm wet tropical (or even sub-tropical like Florida) place knows and lives every day.

Yes, more surface warming will lead to more warm (by which they seem to mean wet-not-freezing) cloud volume. Just before it turns into strongly cooling thunderheads and “tropical storms” as active heat transporting elements of our Global Heat Pipe Earth. There’s a whole sequence of increasing strength heat transport mechanisms that kick in as the surface temperature approaches 84 F anywhere with surface water or lots of plants. “Warm Clouds” are just a way point. VERY Shortly after them comes active “Cold Clouds” dumping ice on the surface. It’s Nature’s Way of saying we will NOT end up in a hot house hell, but rather a sub-tropical paradise, even if it were getting hotter (which it isn’t).

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About E.M.Smith

A technical managerial sort interested in things from Stonehenge to computer science. My present "hot buttons' are the mythology of Climate Change and ancient metrology; but things change...
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15 Responses to Climate Models Get Clouds Wrong – They Cool

  1. Logau says:

    Thermodynamics are not for the uninitiated – and they are not at all amenable to ideological interpretation, nor to analyses guided by superstition. Sorry.

  2. John Hultquist says:

    “The interesting thing is that anyone who lived there any length of time knew about this. ”

    And, at this level, has been included in earth science (i.e., Geography 100) textbooks for many long years.
    One has to take a 300 level class to get the specifics.
    If they keep tweaking the climate models they will catch up real soon.

  3. cdquarles says:

    A minor quibble, but that’s is mostly because of my locality. Wet season here is November through June. Dry season is July through October. Why? 1. Gulf of Mexico and 2. Timing of and track of mid-latitude systems. The only thing that keeps my area from being very dry in summer to mid-autumn is tropical systems. Otherwise, the atmospheric conditions that give the south-western monsoon would make it so. Tropical systems go around highs and toward lows. The “Bermuda High”, aka the downward edge of the tropical Hadley Cell, parks either near us or over us. When over us, it gets Hot, Hazy and Dry, with the exception of all of the water the vegetation transpires. When near but east, it gets Hot, Hazy, and Humid; with the above mentioned afternoon to evening thundershower possibility.

    That reminds me, the remnants of a second tropical system passed through this morning; dropping 3/4ths of an inch of rain in a couple of hours. Oh, it has been on the cool side this year, too. I want to say that we’ve had fewer than 7 days of 90+ so far and about half of those were in the last few days of May; where in a typical year we’ve had about 30 days of such. After this system goes through, they’re talking low 60s to mid 80s for the end of the week (hmm, first few days of July).

  4. cdquarles says:

    Oh, there is another thing they get wrong about carbon dioxide, in addition to the fact that making the adiabatic lapse rate move more toward the moist one, is that water droplet clouds scrub carbon dioxide from the air. Surface conditions matter more than they think.

  5. tom0mason says:

    Well said EMSmith,
    Indeed often my questions to believers in ‘AGW Climate Crisis’ is to reference the Trenberth ‘energy balance’ diagram similar to this one …

    Diagram is an edited version from Trenberth et al. 2009 paper(, it being an update of that in the IPCC report of 2007.

    Our sky has a patchwork of clouds and clear areas, and the clouds move around as they are driven by the local and regional winds above the land and seas. These winds are mostly caused by the pressure differentials and gradients that exist between local and regional air masses (high and low pressure areas).
    Clouds over the planet have a mass of many billions (or trillions) of tons (NASA says “About 100 trillion tons of water falls on land each year, compared to 400 trillion tons over the oceans.” [mainly from the clouds. Where are the more accurate figures for these clouds? -TM]).
    So overall there is a huge weight of water being moved by the winds all over the planet. This is done by real work, and to do real work demands energy to do it.
    I’ll ask some simple questions —
    1. Where does the energy for lifting trillions of tons of cloud water come from, and where is it accounted for, and who’s verified it Mr. Trenberth?
    2. Where in Trenberth et al. diagram is the substantial amount of energy accounted for, as it blows trillions of tons of air and water around our planet?
    3. Can any of this energy (which is originally a product of solar heating) be radiated back off the planet?

    As far as I can see none of it is correctly accounted for.

  6. E.M.Smith says:

    I also note the only evaporation mentioned is an “80” sized “evapotranspiration”. I’m pretty sure that’s a few orders of magnitude low for all evaporation. Then what happens to it? IT STOPS at an “absorbed by atmosphere” and just disappears… (along with the heat in thermals).

    The silly thing in it is the “all about radiation” focus when it is convection that operates in the troposphere. The troposphere exists because radiation is insufficient to move the heat. The troposphere runs at a rate proportional to the heat input and moves 100% of input back to the tropopause to be radiated away. You can see this in the differential rates of convection in cold places like the Arctic / Canadian winter vs Tropics / Florida summer. It’s a rate proportional feedback loop driven heat pipe removing the heat. That’s how a heat pipe works.

    Somebody needs to get a heat pipe engineer to make a similar chart for convection / evaporation.

  7. philjourdan says:

    I do not live in the tropics, but on the muggy east coast. So we do not get daily rain showers, but when we do get a shower, only a moron would not understand what is happening. We usually get a 20 degree drop in a matter of minutes.

    Of course if we have a near miss (it goes just past us), then we get the extra humidity and no relief from the temperature! That sucks!

  8. Julian Jones says:

    Thank you EM; the role of evapotranspiration seriously overlooked by IPCC, but some small signs of academia waking up to this.
    Part of the tragedy of environmental/climate movements is their ignorance of this – its condemning millions round the world to desperate water shortages, at the least … An apparent denial of ‘Water Cycle 101’, the sort of overview we used to learn aged around 11 in my day, is quite extraordinary.
    Its not just deforestation that is contributing here to aridification but also draining of wetlands and especially compaction / tillage / fertiliser practices etc on farmland that are all compromising evapotranspiration, and ironically the natural carbon sequestration cycle.
    One possible cause, as mentioned before, of reduction in snow pack/glaciation downwind of such aridified landscapes.
    An overview here, Ing. Michal Kravčík, CSc., 2007 :
    Our most intense summer storms here in UK very often arise just after harvest; convective storm rainfall driven by the rapid evapotranspiration off the bare compacted / decarbonised farmland. Not hard to fix – but a big cultural shift for farmers (which is underway, orgs like Savory Institute & PFLA).

  9. David A says:

    Like many physical energy processes, this does not appear to be linear at all.
    Which make me think the entire ECS number for doubling C02 cannot possibly be linear. If earths mean T increases two degrees F, it must take a greater increase of energy to elevate the mean another two degrees.

  10. tom0mason says:

    Indeed EMSmith,
    My take on this climate thing is that the lower 2/3(or so) of the troposphere has mainly by convection effect moving the energy around, with little to no radiative effect (it’s nearly all movement!). The upper ~1/3 is a mix of movement and radiation, while above that it is mostly radiation. Just like your heat-pipe idea.
    April 29, 2014. In the early morning imagery from today (April 29) AIRS data showed minimum temperature to be near 190 kelvin (-117.7 F/-83.1 C), which is even colder than yesterday. That means the storms early this morning were higher in the atmosphere …
    … On April 28, AIRS data showed some thunderstorms with cloud tops as cold as 200 kelvin (-99.6 F/-73.1C). See more HERE.

    But this report trumpeted …
    Earth’s record low temperature of -111°C recorded atop of the thunderstorm clouds in the tropical Pacific on Dec 29th, 2018. (More HERE )

    So far I’ve gone back to look at 9 other recent storms from various sources, and they all show very low temperatures at the cloud tops(-90°C to -100°C range). What I have noted is that if I go back to the 1990s they were about 6-10°C warmer.(I’ve only found 3 so far having this type of temperature data, so very small sample size).
    Maybe the upper troposphere is cooling (perhaps only regionally and patchy) so allowing these colder temperatures to show themselves and initializing the large number of deluges, tornadoes, and hail storms that are currently showing-up around the world — see HERE and HERE for these weather events.
    As reported here ->

    Cloud-top temperatures are significantly negatively correlated with increasing aerosol index (AI) over oceans and aerosol optical depth (AOT) over land for deep mixed-phase clouds with liquid droplets near the warm bases and ice crystals near the cold tops; no significant changes were found for uniformly liquid clouds. Precipitation rates are positively correlated with the AI for mixed-phase clouds, but negatively correlated for liquid clouds.

    Wouldn’t the current up-tick in volcanic activity resulting in more atmosphere particulates be the source of this cooling as well as the lax solar energy flow.

  11. E.M.Smith says:

    @David A:

    I’m pretty sure you could make an estimate of the non-linearity just by looking at sea surface temperatures and total precipitation in the Arctic vs Mid Latitude Pacific vs Tropical / Equatorial.

    To me, it looks like it is SO non-linear that it is almost impossible to go above about 86 F water surface temperature without sprouting monster heat transfer engines like Hurricanes. At the other end, water that’s frozen lets the stratosphere touch the ground in Antarctica… Get numbers for a couple of mid-points and I think you can plot a curve…

    The water vapor, cloud fraction, and precipitation maps here ought to illustrate it nicely:

    Insolation varies as the cos? of latitude so just plot that against water vapor or precipitation and you ought to have it.

  12. philjourdan says:

    @EM – here is another easy observation for the AGW idiots. Drive I-8 from San Diego to El Centro with an external thermometer. (most new cars come with that). Watch the temp. From Ocotillo to the West Canal, the temperature registers about 5 degrees warmer than from the West Canal to El Centro.

    Why? Same elevation, same latitude and Longitude (roughly), same weather pattern.

    DUH! All the plants (there is no farming except between the canals) are transpiring. which is cooling the temperature! I have made the trip many times and it is always the same.

  13. The True Nolan says:

    The CAGW enthusiasts are back at it again screaming that cattle farts are releasing too much methane. It’s the same old story. Blame everything bad on pootin’.

  14. H.R. says:

    TTN: “Blame everything bad on pootin’.”

    Yah… muuuuh Russia! Russia! Russia!

    Oh wait… 😜

  15. E.M.Smith says:


    That joke just stinks….

    Badum bump… ;-)

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