[FRIAM] Climate Modeling

Sun Jan 19 16:58:30 EST 2020

Oh... also an interesting report on the Shared Socioeconomic Pathways
(SSPs) as canonical scenarios to be used with these models.
>
> Eric -
>
> Great back-of-envelop summary/speculation and I second your desire for
> someone well-steeped in these modeling/assessment issues.
>
> We (speaking out of school for Merle, Stephen, and the team that went
> to and met with the Stockholm Team last month) would love to find
> someone with that depth/breadth of knowledge in this group (or one
> degree away).  I am remiss/slow in following up with the *one* member
> of the Stockholm Resilience Center I met there who *might* either have
> this level of depth/breadth or know someone who does.
>
> I am trying hard to come up to speed, but the number of models and
> types of approaches and hidden agendas/constraints/assumptions are
> still overwhelming.   The IPCC seems to be the *best* official source
> that is most broadly accepted, etc.  but tends to be one or two levels
> of detail above the kinds of questions I have (and you are asking here).
>
> I am interested in something much broader than just the
> geo/bio/cryo/hydro/aero-science of it all, though THAT is huge and
> complicated enough as it is.   The Integrated Assessment Models that
> join this *physical* domain with the socio(political)economic domain
> seems most well discussed by the work of the Coupled Model
> Intercomparison Project (CMIP) lead by LLNL and tied into the World
> Climate Research Programme (WCRP) who are providing some of the "heavy
> lifting" for the IPCC's next (VI) report due in 2021.
>
>     https://en.wikipedia.org/wiki/Coupled_Model_Intercomparison_Project
>
>     https://www.wcrp-climate.org/
>
> - Steve
>
> On 1/19/20 2:00 PM, David Eric Smith wrote:
>> 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
>>> <pieters at randcontrols.co.za <mailto:pieters at 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/_
>>>
>>> On Sat, 18 Jan 2020 at 22:36, Jochen Fromm <jofr at cas-group.net
>>> <mailto:jofr at 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
>>>
>>>
>>>     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/
>>>
>>>     -Jochen
>>>
>>>
>>>     ============================================================
>>>     FRIAM Applied Complexity Group listserv
>>>     Meets Fridays 9a-11:30 at cafe at St. John's College
>>>     to unsubscribe http://redfish.com/mailman/listinfo/friam_redfish.com
>>>     archives back to 2003: http://friam.471366.n2.nabble.com/
>>>     FRIAM-COMIC http://friam-comic.blogspot.com/ by Dr. Strangelove
>>>
>>> ============================================================
>>> FRIAM Applied Complexity Group listserv
>>> Meets Fridays 9a-11:30 at cafe at St. John's College
>>> to unsubscribe http://redfish.com/mailman/listinfo/friam_redfish.com
>>> archives back to 2003: http://friam.471366.n2.nabble.com/
>>> FRIAM-COMIC http://friam-comic.blogspot.com/ by Dr. Strangelove
>>
>>
>> ============================================================
>> FRIAM Applied Complexity Group listserv
>> Meets Fridays 9a-11:30 at cafe at St. John's College
>> to unsubscribe http://redfish.com/mailman/listinfo/friam_redfish.com
>> archives back to 2003: http://friam.471366.n2.nabble.com/
>> FRIAM-COMIC http://friam-comic.blogspot.com/ by Dr. Strangelove
>
> ============================================================
> FRIAM Applied Complexity Group listserv
> Meets Fridays 9a-11:30 at cafe at St. John's College
> to unsubscribe http://redfish.com/mailman/listinfo/friam_redfish.com
> archives back to 2003: http://friam.471366.n2.nabble.com/
> FRIAM-COMIC http://friam-comic.blogspot.com/ by Dr. Strangelove
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://redfish.com/pipermail/friam_redfish.com/attachments/20200119/3a344427/attachment.html>