Would be interesting to know what the buffers are, that weren’t in that run of 
models.

Temperatures are lower than forecast, but Greenland and Antarctic ice sheet 
melting rates are higher.  They seem like small land areas, and the ice volume 
small, but specific heat of melting is large per volume compared to specific 
heat of air, and the atmosphere, while thick compared to ice, is only 10-20 km 
high (to the top of the troposphere; stratosphere up to maybe 50km at 
much-reduced density and much increased transparency because it is dry).  So 
troposphere maybe 20-40 times the depth of the west antarctic ice sheet, though 
only a lowermost layer of that is melting, and I don’t know the thickness per 
unit time lost.  Specific heat of dry air is about 1 J/gK, while heat of 
melting of clean water is 334 J/g.  Ice is about 1000 times as dense as air, so 
one has a volume ratio of about 3x10^5 to play with, per degree Kelvin.  

Greenland plus Antarctica (wikipedia-level area estimates) are about 3% of 
earth surface area.  So if one divided by a column density ratio of 30:1 and 
multiplied by an area ratio of 0.03, one has about 1/1000.  So a full melt of 
Greenland and Antarctic ice could buffer about 300K of atmospheric temperature 
change at a dimensional-analysis-level estimate.  If the full rate of melting 
were mis-estimated by a factor that extends the ice sheet lifetimes by 600 
years, that would give about 1/2 degree per year buffering capacity.

I don’t know what is or isn’t in the models up to 2014, because I haven’t 
followed these things closely, but unless what I wrote above is nonsense, it 
seems that a mis-estimate of just continental ice sheet melting is not wildly 
out of scale to account for unmodeled buffers.

One also wants to take into account arctic se ice, which if I really is on a 
faster melting schedule then some models predicted, though I don’t have even a 
good impressionistic memory of what I have heard on that.

And of course there is the heat-transport rate of cyclonic storms, from sea 
surface to the top of the troposphere, where radiative transfer through the 
stratosphere will be much faster than that from the interior of the troposphere 
or the surface.  My understanding is that predicting frequency and intensity of 
typhoons etc. is still something of a challenge area, but I don’t know if that 
affects parameters used in GCM and heat-transfer models enough to count as an 
un-modeled buffer.

Would be great if there is somebody on this list who has a comprehensive enough 
knowledge of the state of this literature to give the kind of survey of the 
state of the art in response to questions, that is hard to get from broadcast.  
Good as it is, broadcast just contains whatever it contains, and doesn’t have 
the responsiveness of a person who can hear a question in context and then 
recruit knowledge for a matched reply.

Eric





> On Jan 20, 2020, at 1:55 AM, Pieter Steenekamp <piet...@randcontrols.co.za> 
> wrote:
> 
>  
> Fortunately it seems that the earth is warming much slower than what the 
> models predicted. So just maybe we have hope?
>  
>  
> <image.png>
>  
> https://judithcurry.com/2015/12/17/climate-models-versus-climate-reality/ 
> <https://judithcurry.com/2015/12/17/climate-models-versus-climate-reality/>
> On Sat, 18 Jan 2020 at 22:36, Jochen Fromm <j...@cas-group.net 
> <mailto:j...@cas-group.net>> wrote:
> Trump's channel Fox News is owned by the Australian Murdoch family. Can two 
> families ruin the entire planet? Trump in America and Murdoch in Australia 
> are creating tremendous damage. If Climate Change leads to an uninhabitable 
> world, as David Wallace-Wells describes in his book, these two families 
> certainly contributed to it
> https://www.amazon.com/dp/B07GVPFH5V/ref=dp-kindle-redirect?_encoding=UTF8&btkr=1
>  
> <https://www.amazon.com/dp/B07GVPFH5V/ref=dp-kindle-redirect?_encoding=UTF8&btkr=1>
> 
> The Washington Post writes:
> "When we think of industries that must change to prevent further global 
> warming, we tend to imagine carbon-intensive concerns such as mining, 
> aviation and energy production. But the Murdoch media and the rest of the 
> climate denialist industry will also need a transition plan. They do not have 
> long to implement it."
> https://www.washingtonpost.com/opinions/2020/01/16/australias-catastrophic-fires-are-moment-reckoning-murdochs-media-empire/
>  
> <https://www.washingtonpost.com/opinions/2020/01/16/australias-catastrophic-fires-are-moment-reckoning-murdochs-media-empire/>
> 
> -Jochen
> 
> 
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