March 1st, 2019 by Roy W. Spencer, Ph. D.
I’ve received many more requests about the new disappearing-clouds study than the “gold standard proof of anthropogenic warming” study I addressed here, both of which appeared in Nature journals over the last several days.
The widespread interest is partly because of the way the study is dramatized in the media. For example, check out this headline, “A World Without Clouds“, and the study’s forecast of 12 deg. C of global warming.
The disappearing clouds study is based upon the modelling of marine stratocumulus clouds, whose existence substantially cools the Earth. These extensive but shallow cloud decks cover the subtropical ocean regions over the eastern ocean basins where upwelling cold water creates a strong boundary layer inversion.
Marine stratocumulus clouds off the U.S. West Coast, which form in a water-chilled shallow layer of boundary layer air capped by warmer air aloft (NASA/GSFC).
In other words, the cold water causes a thin marine boundary layer of chilled air up to a kilometer deep, that is capped by warmer air aloft. The resulting inversion layer (the boundary between cool air below and warm air aloft) inhibits convective mixing, and so water evaporated from the ocean accumulates in the boundary layer and clouds then develop at the base of the inversion. There are complex infrared radiative processes which also help maintain the cloud layer.
The new modeling study describes how these cloud layers could dissipate if atmospheric CO2 concentrations get too high, thus causing a positive feedback loop on warming and greatly increasing future global temperatures, even beyond what the IPCC has predicted from global climate models. The marine stratocumulus cloud response to warming is not a new issue, as modelers have been debating for decades whether these clouds would increase or decrease with warming, thus either reducing or amplifying the small amount of direct radiative warming from increasing CO2.
The new study uses a very high resolution model that “grows” the marine stratocumulus clouds. The IPCC’s climate models, in contrast, have much lower resolution and must parameterize the existence of the clouds based upon larger-scale model variables. These high resolution models have been around for many years, but this study tries to specifically address how increasing CO2 in the whole atmosphere changes this thin, but important, cloud layer.
The high resolution simulations are stunning in their realism, covering a domain of 4.8 x 4.8 km:
The main conclusion of the study is that when model CO2 concentrations reach 1200 ppm or so (which would take as little as another 100 years or so assuming worst-case energy use and population growth projections like RCP8.5), a substantial dissipation of these clouds occurs causing substantial additional global warming, with up to 12 deg. C of total global warming.
Shortcomings in the Study: The Large-Scale Ocean and Atmospheric Environment
All studies like this require assumptions. In my view, the problem is not with the high-resolution model of the clouds itself. Instead, it’s the assumed state of the large-scale environment in which the clouds are assumed to be embedded.
Most importantly, it should be remembered that these clouds exist where cold water is upwelling from the deep ocean, where it has resided for centuries to millennia after initially being chilled to near-freezing in polar regions, and flowing in from higher latitudes. This cold water is continually feeding the stratocumulus zones, helping to maintain the strong temperature inversion at the top of the chilled marine boundary layer. Instead, their model has 1 meter thick slab ocean that rapidly responds to only whats going on with atmospheric greenhouse gases within the tiny (5 km) model domain. Such a shallow ocean layer would be ok (as they claim) IF the ocean portion of the model was a closed system… the shallow ocean only increases how rapidly the model responds… not its final equilibrium state. But given the continuous influx of cold water into these stratocumulus regions from below and from high latitudes in nature, it is far from a closed system.
Second, the atmospheric environment in which the high-res cloud model is embedded is assumed to have similar characteristics to what climate models produce. This includes substantial increases in free-tropospheric water vapor, keeping constant relative humidity throughout the troposphere. In climate models, the enhanced infrared effects of this absolute increase in water vapor leads to a tropical “hot spot”, which observations, so far, fail to show. This is a second reason the study’s results are exaggerated. Part of the disappearing cloud effect in their model is from increased downwelling radiation from the free troposphere as CO2 increases and positive water vapor feedback in the global climate models increases downwelling IR even more. This reduces the rate of infrared cooling by the cloud tops, which is one process that normally maintains them. The model clouds then disappear, causing more sunlight to flood in and warm the isolated shallow slab ocean. But if the free troposphere above the cloud does not produce nearly as large an effect from increasing water vapor, the clouds will not show such a dramatic effect.
The bottom line is that marine stratocumulus clouds exist because of the strong temperature inversion maintained by cold water from upwelling and transport from high latitudes. That chilled boundary layer air bumps up against warm free-tropospheric air (warmed, in turn, by subsidence forced by moist air ascent in precipitation systems possibly thousands of miles away). That inversion will likely be well-maintained in a warming world, thus maintaining the cloud deck, and not causing catastrophic global warming.
In reply to:
“The main conclusion of the study is that when model CO2 concentrations reach 1200 ppm or so (which would take as little as another 100 years or so assuming worst-case energy use and population growth projections like RCP8.5), a substantial dissipation of these clouds occurs causing substantial additional global warming, with up to 12 deg. C of total global warming.”
Your above comment is not correct.
This is an important option/issue to at least summarize and discuss, as it is a fact that there is no solution to CAGW and well-meaning, organized people are proceeding to destroying our economies to fight CAGW with a solution that does not work.
It is a scandal that there are multiple peer reviewed papers, multiple authors (Atomic Bomb produced C14 resident time analysis, C13 change analysis, mass balance analysis human emission vs atmospheric CO2 change, transient analysis, phase analysis, and so on) that have all shown that human burning of deep earth hydrocarbons caused less than 5% of the recent rise in atmospheric CO2.
It is a fact that in the last 40 years atmospheric CO2 levels have tracked planetary temperature changes and have not tracked anthropogenic CO2 emission changes.
The following is an excellent summary of the history of CO2 atmospheric measurements and adjustments and a critique of the so called ‘Bern model’ of CO2 sinks and sources and resident times.
Comment: The called ‘Bern model’ was specifically created at the university of Bern by a few guys, to support the paradigm of CAGW.
Carbon cycle modelling and the residence time of natural and anthropogenic atmospheric CO2: on the construction of the “Greenhouse Effect Global Warming” dogma.
https://www.co2web.info/ESEF3VO2.pdf
‘13-C/12-C isotope mass balance calculations show that IPCC’s atmospheric residence time of 50-200 years make the atmosphere too light (50% of its current CO2 mass) to fit its measured 13-C/12-C isotope ratio. This proves why IPCC’s wrong model creates its artificial 50% “missing sink”. IPCC’s 50% inexplicable “missing sink” of about 3 giga-tonnes carbon annually should have led all governments to reject IPCC’s model.’
‘Callendar (1938) revived the hypothesis of “Greenhouse Warming” due to Man’s activity, proposed by Arrhenius (1896). Callendar may truly be regarded as the father of the current dogma on man-induced global warming (Jaworowski et al., 1992 b). In order to support his hypothesis, Callendar (1940, 1958) selected atmospheric CO2 data from the 19th and 20th centuries. Fonselius et al. (1956) showed that the raw data
ranged randomly between about 250 and 550 ppmv (parts per million by volume) during this time period, but by selecting the data carefully Callendar was able to present a steadily rising trend from about 290 ppmv for the period 1866 – 1900, to 325 ppmv in 1956.’
“Callendar was strongly criticized by Slocum (1955), who pointed out a strong bias in Callendar’s data selection method. Slocum pointed out that it was statistically impossible to find a trend in the raw data set, and that the total data set showed a constant average of about 335 ppmv over this period from the 19th to the 20th century. Bray (1959) also criticized the selection method of Callendar, who rejected values 10%
or more different from the “general average”, and even more so when Callendar’s “general average” was neither defined nor given.”
Obviously if the resident time of CO2 in the atmosphere is less than 5 years, rather than the Bern model resident time of greater than 100 years and 25% staying in the atmosphere forever, there is no CAGW or AGW crisis. We can burn hydrocarbons without worry and move on to trying to understand what causes planetary temperature change.
In the tropics, there are less clouds in the “winter” when it is relatively cool and dry and more clouds in “summer” when it is relatively hot and humid. This contradicts the model.
Why? The model appears defective in that it did not consider a decrease in one type of cloud might result in an increase in another type of cloud.
in the tropics, as it gets hotter, the low lying clouds are replaced by towering thunderstorms, which if anything provide even greater cooling of the surface, not less.
There are enormous swathes of tropical ocean that do not have cold surface currents. They are not cloudless. Every day the sun heats the surface of the ocean. Warm moist air rises. As it rises it cools and water vapor condenses into water droplets releasing more energy. This process creates cumulus clouds. The clouds yield thunderstorms that Willis Eschenbach has identified as the principal thermal regulatory mechanism of the planet.
The following are a couple of papers that support the assertion made above that the recent changes in atmospheric CO2 were caused by the increase in planetary temperature, not by anthropogenic CO2 emissions.
The below papers agree with the recent analysis of Salby (Salby is the Australian scientist who has fired for giving presentations of analysis using standard IPCC data sets, that showed humans were not the cause of the majority of the recent rise in atmospheric CO2.)
Salby’s and the analysis below show there must be a large input of CO2 into the atmosphere besides the CO2 in volcanic eruptions which is the single assumed source of CO2 for the Bern model.
This is Salby’s most recent video.
https://www.youtube.com/watch?time_continue=610&v=rohF6K2avtY
What makes this subject (what is the new source of CO2 into the atmosphere that almost everyone missed) interesting and fun for a general audience is it possible using recent and past geological observations, which have been summarized by others, that are in a picture form to prove to any person using physical logic what/were the missing source of CO2 and H20 is.
(Recent analysis shows there is three times more H20 moving into the mantel than is coming out in volcanic eruptions. There of course must be a new source of H2O or the planet would turn into a desert.)
http://icecap.us/images/uploads/EE20-1_Quirk_SS.pdf
https://www.researchgate.net/publication/257343053_The_phase_relation_between_atmospheric_carbon_dioxide_and_global_temperature
Thanks for the links William. Useful information.
you cannot ‘calculate’ that which has never been mesured before…
It appears to me that they are expecting the oceanic currents to shut down (they won’t-too much mass involved). The reason for the upwelling which causes the cool air which in turn causes the stratocumulus clouds is Coriolis force acting on the southward moving California Current to drag water away from the coast and thus causing upwelling.
I wrote above that Average UK sun hours mirror the temperature rise. To me this is highly significant because it means solar radiation over a longer period. Less cloud. Can someone give me a sensible response?
We see something like this during the winter in our broad mountain valley. As the sun sets on a snow and ice-covered surface the temperature begins to plummet. However, quite often there is a thin veil of clouds which develop at the interface between the cold surface air and warmer air above. Keeps us maybe 10F warmer at night than would prevail under a clear night sky.
As we all know, global warming is the cause of everything. I soon expect to see a modeling study showing a significant negative cloud feedback causing dangerous ice age conditions.
Because Nature just is not coming to their party, the Warmistas are having to work the Models overtime and put them on steroids to come up with the necessary scary scenarios to control the population to the party line.
Two points:
First, the post notes that “cold water is continually feeding the stratocumulus zones, helping to maintain the strong temperature inversion at the top of the chilled marine boundary layer. Instead, their model has 1 meter thick slab ocean that rapidly responds to only whats going on with atmospheric greenhouse gases within the tiny (5 km) model domain. . . . But given the continuous influx of cold water into these stratocumulus regions from below and from high latitudes in nature, it is far from a closed system.”
Isn’t this just a polite way of saying that the model was rigged to produce the results they wanted? Since a computer simply executes whatever instructions it is programmed to implement, how can a mere analysis of results from a computer model fairly qualify as a “study?” I’m fine with using a computer to flesh out a hypothesis. I’m not fine with pretending that the results tell you anything you didn’t already know about the behavior of the system the computer emulates.
Second, if as the post suggests, a constant supply of cold water is being fed to the surface of specific parts of the ocean while the upper atmosphere slowly warms over time, would this not be expected to strengthen the inversion as the atmosphere warms (air above gradually getting warmer while temperature at the surface being held approximately constant by upwelling cold water)? If so, this should be a negative feedback effect instead of the positive feedback hypothesized by the model.
The real ocean is not a shallow surface layer isolated from the deeper colder layer. Cold deep seawater upwelling is a wind-driven phenomenon. In the northern hemisphere, along the illustrated Pacific coast for example, the net water movement is to the right of the wind direction. This is Ekman transport (note comments for corrections to details):
https://www.youtube.com/watch?v=8PB2ykEHpSU
Personal observation along Highway 101 looking south along the coast, a northwest wind would drive surface ocean water offshore, to be replaced by deep cold ocean water. A boundary condition with warm land temperature would result in dense fog and chilly temperature to the right of the highway and clear blue sky and warm temperature to the left.
Satellite and sunshine hours recorded over the world, had detected the global decrease in cloud albedo that occurred since at least the 1980’s. This similar mechanism was very likely the main reason why this cloud albedo decline was associated with the AMO because the North Atlantic ocean and sister ocean/seas had become warmer decreasing stratocumulus zones. The result was warming ocean from the sun during this period because of more sunlight reaching the ocean surface. There is more ocean upwelling associated with the persistent negative AMO then compared with persistent positive AMO phase.
This explains with the ENSO most of the global warming seen so far with the ocean current from the North Atlantic moving until it sinks near the polar ocean.
http://www.woodfortrees.org/plot/uah6/plot/esrl-amo/from:1979/plot/nsidc-seaice-n/from:1979/normalise
So according to he IPCC the clouds are likely net positive, but now less clouds will make it more net positive?
I read the article “a world without clouds” but surely there is an elephant sized problem with what they claim. The basis of widespread warmists claims of positive feedback is the claim of constant relative humidity (humidity relative to the saturation water vapour pressure). That means as temperature rises the air contains progressively more water vapour. But since water vapour is lighter than air that means stronger convection which carries the water vapour away from the surface more quickly. So overall a lot more water evaporating. But unless one wants to argue that the oceans will end up in the sky, more evaporation must be balanced by more precipitation. Maybe they are arguing that the oceans will end up in the sky like on Venus but its not consistent with sea level rise which they also shriek loudly about. Trouble is, if the water returns to the surface as rain, rain only comes from low dense clouds. So are they claiming the rain will come from a clear cloudless sky? WOW that I have to see!!!! Or they are arguing heavy rain will come from high noctilucent clouds – you know, the type that are so thin you can see through them? Maybe the water returns to earth as giant inverted water spouts without ever re-condensing to form clouds? Any other suggestions? I would have expected more evaporation means more rain means more, not less, dense low clouds, but then, I am only basing that on logic and conventional science, things that seem to have become totally alien to the climate science community. sarc/
Nevertheless, I would like to point at the well-known fact of the necessarily stable energy balance of systems “planet” – see “Planet systems” Venus, Jupiter, Saturn.
The energy balance of a planet results of
thermal energy from warming of the atmosphere by pressure of its own weight + energy received from solar radiation – energy loss at TOA = 0
or
thermal energy from warming the atmosphere by pressure from of its own weight + energy received from solar radiation
= Energy loss at TOA
___________________________________________________
If that energy bilances of “Planet systems” weren’t respected in the real world
– properly functioning solar systems WITH planets simply wouldn’t EXIST !
My fault – corrected to:
Nevertheless, I would like to point at the well-known fact of the necessarily stable energy balance of systems “planet” – see “Planet systems” Venus, Jupiter, Saturn.
The energy balance of a planet results of
thermal energy from warming of the atmosphere by pressure of its own weight + energy received from solar radiation – energy loss at TOA = thermal energy of system “planet”
or
thermal energy from warming the atmosphere by pressure from of its own weight + energy received from solar radiation – thermal energy of system “planet” = Energy loss at TOA
___________________________________________________
If that energy bilances of “Planet systems” weren’t respected in the real world
– properly functioning solar systems WITH planets simply wouldn’t EXIST !
Are you pushing Nikolov-Zeller hypotheses Johann? That should be “thoroughly discredited”, not “well-known”.
There is no heating from pressure. The atmosphere would need to be continuously doing work to be a source of heating.
The atmosphere obeys the ideal gas law PV=nRT to the extent that any real gas does. Just as in a gas cylinder, where temperature is free to vary independently based on ambient conditions rather than being determined by the pressure, in the atmosphere, temperature is the independent variable which varies based on the amount of energy coming from the sun.
Insolation is the only significant source of heating. Temperature determines the volume V and ultimately also the number of moles of gas, n. Pressure P is determined by the mass of the atmosphere (set by n and molecular weights of the constituents) and the surface area. R is the universal gas constant. In a static, steady state condition, gas under pressure is not doing work and there is no heat being generated.
Can they get their story straight? Before it was clouds didn’t exist before the Industrial Age because paintings from the Renaissance didn’t show clouds. Now it’s we won’t have clouds because it’s warmer. But wait there’s more, we’re supposed to have more rain on a warmer planet. So I guess there is such a thing as moisture just randomly condensing out of the air and raining spontaneously.