Well, okay, but David Keith is arguing in the opposite direction than me.  He's 
saying, '...so we got time'.  I'm saying we drop global mean temp by a degree 
today, and then we'll actually test for the existence of tipping points in the 
real world, rather than sit on our butts speculating about their possibly 
existence.
 - Greg

> On Feb 14, 2024, at 3:57 PM, Ron Baiman <[email protected]> wrote:
> 
> Hi Greg,
> 
> And as you may recall, there was enormous push back on David Keith's view, 
> that I don't think is credible, at that HPAC meeting (see McKay, Lenton, etc. 
> papers).  In any case, an easy response is that of Doug McMartin when asked 
> about David's view during his (Doug's) HPAC presentation. Can we afford to 
> risk the chance that warming above 1.5 C (or whatever warming we have now!) 
> will (is) leading to crossing irreversible and extremely harmful tipping 
> points (like sea level rise as you've pointed out)?  The obvious answer is 
> that it would be (is) lunacy to assume this kind of risk for human 
> civilization and our fellow living species - whether it pans out or not. 
> 
> Best,
> Ron
> 
> On Wed, Feb 14, 2024 at 5:40 PM Gregory Slater <[email protected] 
> <mailto:[email protected]>> wrote:
> 
> Hi Ron,
> 
> Well, yes, the 'tipping point thing' is presumably key.  From my pedestrian 
> understanding, there's ~50+ ft of sea level rise in the Greenland and the 
> West Antarctic ice sheets alone, so if indeed we've passed whatever relevant 
> 'tipping point' for those ice sheets (for example, undercutting the coastal 
> structure of these sheets in some way, or whatever) then, apparently, we 
> could now cool the earth by 40 deg C at this point, and these sheets would 
> still inexorably melt away.  On the other hand, as you know, David Keith told 
> HPAC staright up that ice sheet tipping points are bulls**t.  Who has the 
> final authoratative word on whether we're past those or other tipping points? 
>  Fas ar I can tell, it's all vapor at this point,  and that therefore 'as far 
> as we know' SAI can stop (not just freaking 'mitigate' (hate that utterly 
> defeatist word!) ) the inevitable 40+ feet of sea level rise - and I'm 
> sticking to that until there's something authoratative on ice sheet tipping 
> points.  We're still not helpless victims of the inevitable ice sheet melt.
> 
> Please correct any misinformed or delusion points in the above.
> 
> Greg 
> 
> 
>> On Feb 14, 2024, at 2:09 PM, Ron Baiman <[email protected] 
>> <mailto:[email protected]>> wrote:
>> 
>> Hi Greg, The problem is that some melting processes, once set in motion, 
>> become irreversible on human time scales as reforming the ice would require 
>> extremely cold temperatures over extended periods of time. The ice will not 
>> be restored by simply going back to pre-industrial temps (technically called 
>> ‘hysteresis’ , ‘path dependency’ or simply irreversibility). 
>> My understanding is that we have likely started some of these irreversible 
>> tipping points.  But totally agree that slowing and stopping melting as much 
>> as possible should be a priority. I think we can restore polar sea ice for 
>> example by urgent cooling.  And if we can slow the melting down to centuries 
>> for example it would be much easier for human civilization to adapt. 
>> Best,
>> Ron 
>> 
>>> On Feb 14, 2024, at 4:41 PM, Gregory Slater <[email protected] 
>>> <mailto:[email protected]>> wrote:
>>> 
>>> Hello Ron,
>>> 
>>> Thanks for reply and link.  I'll look at this.
>>> However. Ron. It totally depresses me when you write, "At this point it 
>>> appears that it may be very hard to reverse substantial sea level rise over 
>>> next centuries....".  Seriously?  Why?  The only, only reason I am 
>>> interested in SAI (and the other cooling technologies) is its capability to 
>>> halt global warming and sea level rise immediately.  Today.  If we but 
>>> choose to do so.  Is there anyone who actually doubts that SAI can halt 
>>> global warming and sea live rise immediately?  Is there anyone who does not 
>>> think we have the capacity to do this?  This is my baseline assumption.  
>>> That, whether or not we have the brains and the balls to do so, we have the 
>>> technology to actually halt global warming ~instantly.  We have that 
>>> capacity.  Now.  Does anyone seriously disagree with that?
>>> 
>>> Thanks,
>>> Greg Slater
>>> 
>>> 
>>> On 2/13/24 12:26 PM, Ron Baiman wrote:
>>>> Agreed Greg!  At this point it appears that it may be very hard to reverse 
>>>> substantial sea level rise over next centuries but we should at least be 
>>>> trying to slow it down and minimize it as much as possible!
>>>> 
>>>> Jim's short summary of OTEC from (6/19/2023) from p. 15-16 of "The Case 
>>>> for Urgent Direct Climate Cooling" (slight mislabeling on the HPAC 
>>>> website): 
>>>> https://drive.google.com/file/d/1yHe2Fe6fU11odfcH-4GwdYDNTCk7uB-J/view 
>>>> <https://drive.google.com/file/d/1yHe2Fe6fU11odfcH-4GwdYDNTCk7uB-J/view>
>>>> is copied below.  
>>>> 
>>>> Best,
>>>> Ron
>>>> 
>>>> "Ocean Thermal Energy Conversion (OTEC) would utilize the temperature 
>>>> difference
>>>> between surface and deeper ocean waters to cool the planet while 
>>>> generating baseload
>>>> energy and removing CO2 from the atmosphere.76,77,78 Deployment of 31,000 
>>>> one
>>>> gigawatt OTEC plants has been estimated to: a) displace 0.8 W/m2 of 
>>>> average global
>>>> surface heat from the surface of the ocean to deeper water for 200 years; 
>>>> b) produce 31
>>>> terawatts of electricity per year (67% more than total world use), and c) 
>>>> absorb about
>>>> 4.3 GtCO2 per year from the atmosphere by cooling ocean surface waters.79 
>>>> At an
>>>> estimated cost of $2.9 trillion per year, it would take 30 years to ramp 
>>>> up to 31,000
>>>> 
>>>> 73 Nature Communications 12: 6713 (2021).
>>>> 74 Sci. Rep. 6: 35070 (2016).
>>>> 75 White-roofed greenhouses in Almeria have cooled the regional climate.
>>>> 76 Rau, Greg and Jim R. Baird. 2018. Negative-CO2-emissions ocean thermal 
>>>> energy conversion. Renewable and
>>>> Sustainable Energy Reviews 95:265-272.
>>>> 77 Baird, Jim. 2022. The physics and economics of thermodynamic 
>>>> geoengineering. Available from the author upon
>>>> request at [email protected] <mailto:[email protected]>.
>>>> 78 Gleckler PJ, Durack RJ, Stouffer RJ, Johnson GC, Forest CE. 
>>>> Industrial-era global ocean heat uptake doubles in
>>>> recent decades.2016. Nature Climate Change: 
>>>> https://doi.org/10.1038/nclimate2915 <https://doi.org/10.1038/nclimate2915>
>>>> 79 Renforth, Phil and Gideon Henderson. 2017. Assessing ocean alkalinity 
>>>> for carbon sequestration. Reviews of
>>>> Geophysics.
>>>> 
>>>> Healthy Planet Action Coalition Petition to World Leaders Page
>>>> 16
>>>> plants.80,81,82,83 Economies of scale have been estimated to potentially 
>>>> reduce the cost of
>>>> OTEC electricity to about 1.1 cents per KWh.84"
>>>> 
>>>> On Tue, Feb 13, 2024 at 1:05 AM Gregory Slater <[email protected] 
>>>> <mailto:[email protected]>> wrote:
>>>> 
>>>> Hello Jim,
>>>> 
>>>> Thank you for the reply and information about 'thermodynamic 
>>>> geoengineering'.  I do not know this technology.  I am still learning.  
>>>> Please send links to more detailed summaries of the technology.
>>>> 
>>>> My bottom line is that the over-riding priorities must be to stabilize 
>>>> (and reduce) global mean temperature, and stabilize global mean sea level. 
>>>>  Immediately.  Not in years or decades.  Whatever set of technologies can 
>>>> realistically make that happen should be carefully but swiftly deployed, 
>>>> with appropriate testing, modifications, and scale up, but as quickly as 
>>>> possible.  It is an emergency, an actual crisis,  No time to lose.  
>>>> Whatever gets this done the fastest I am in favor of.
>>>> 
>>>> There should be a session on this technology along with all the others at 
>>>> the 'effective geoengineering' conference/summit that I am proposing.
>>>> 
>>>> Thanks,
>>>> Greg Slater
>>>> 
>>>> 
>>>>> On Feb 12, 2024, at 10:04 PM, Jim Baird <[email protected] 
>>>>> <mailto:[email protected]>> wrote:
>>>>> 
>>>>> Gregory, what is the fault in this logic?
>>>>>  
>>>>> The thermal coefficient of expansion of seawater is about half at a depth 
>>>>> of 1,000 meter it is at the surface per the following graphic.
>>>>> 
>>>>> <image002.jpg>
>>>>> Heat moved into deep water to a median depth of 500 meters as 
>>>>> Thermodynamic Geoengineering would provides with heat pipes produces 25% 
>>>>> less sea level rise due to thermal expansion. And this heat would be 
>>>>> unavailable to melt icecaps, or the glaciers that accounted for about 21% 
>>>>> of the recorded sea level rise of the past two decades.
>>>>> 
>>>>> I share your concern with coastlines. 
>>>>> 
>>>>> Jim Baird
>>>>> 
>>>>>  
>>>>>  
>>>>> From: [email protected] 
>>>>> <mailto:[email protected]> On Behalf Of 
>>>>> Gregory Slater
>>>>> Sent: Monday, February 12, 2024 8:55 PM
>>>>> To: Ron Baiman <[email protected] <mailto:[email protected]>>
>>>>> Cc: [email protected] 
>>>>> <mailto:[email protected]>; 
>>>>> [email protected] <mailto:[email protected]>; 
>>>>> healthy-planet-action-coalition 
>>>>> <[email protected] 
>>>>> <mailto:[email protected]>>
>>>>> Subject: Re: [HPAC] A general question about the thermal response of the 
>>>>> Earth's oceans..
>>>>>  
>>>>>  
>>>>> Hi Ron,
>>>>>  
>>>>> Thanks for the link.  I had not read this, though I am sure you and 
>>>>> others announced it when it came out.
>>>>>  
>>>>> My question reflects my interest in understanding the likely net zero 
>>>>> 'end-state' that is the focus of the vast share of discussion around 
>>>>> global warming and climate change, and your paper discusses that.  
>>>>> Certainly I regard even the current state of the Earth with regard to 
>>>>> atmospheric CO2 to be unacceptable, let alone where ever we 'land' at net 
>>>>> zero.  My specific interest in the question is where sea level ends up 
>>>>> upon reaching the (still quite hypothetical) 'net zero'.  But of course, 
>>>>> where ever we 'land' at net zero, that's not the end of the story, nor of 
>>>>> humanity's suffering.  The ice sheets are melting, and the ocean are 
>>>>> rising due to that melt, even where we are now.  Net zero does not in any 
>>>>> way stop that melting and sea level rise (on any timescale that matters 
>>>>> for the stability of states and civilization).  Nor of course, does the 
>>>>> entire spectrum of other increasingly catastrophic global warming-induced 
>>>>> effects stop at 'net zero'.  This disconnect seems to pervade the global 
>>>>> debate. Of course, you and most people on this forum are more aware of 
>>>>> all this than me.  Without one or more (or better, all) of the proposed 
>>>>> methods of climate intervention, we will definitely be 'giving up' on the 
>>>>> coastal cities of the world, and astonishingly, that fate seems 
>>>>> increasingly to be being actively embraced by activists, scientists, and 
>>>>> leaders (at least in the industrialized world).  But I have absolutely no 
>>>>> intention of docilely embracing the inundation of the coastlines, 
>>>>> complete with all of the catastrophies, death, and suffering (to be borne 
>>>>> by the poor and disenfranchised alone!) that that 'embrace of death' 
>>>>> entails.  To hell with the global warming accommodators.  I refuse to 
>>>>> give up on the coastlines.  I'll say it again.  I refuse to give up on 
>>>>> the coastlines!  That's insanity.  It is this decision!, to abandon the 
>>>>> coastlines, It is this decision! and not the decision to seriously begin 
>>>>> testing all forms of climate intervention, that is being made by the rich 
>>>>> and powerful right now, the class that can protect itself from the 
>>>>> consequences, without any involvement of the billions of poor and 
>>>>> disenfranchised of the world, who will be forced to suffer as a result.  
>>>>> As Thucydides so presciently wrote about global warming 2500 years ago, 
>>>>> the rich will resist global warming intervention and the poor will be 
>>>>> forced to 'suffer what they must'.
>>>>>  
>>>>> When it comes to the 'debate' about whether to employ climate 
>>>>> intervention technologies, it's a totally rigged game, with the 
>>>>> established powers in science and politics playing the role of 'the 
>>>>> house'.
>>>>>  
>>>>> I believe that those of us who understand that intervention is not only 
>>>>> doable but absolutely essential, that stabilizing the global mean 
>>>>> temperature is the single most important thing to be done right now, 
>>>>> today, should organize our own conference on how we must proceed, rather 
>>>>> than begging the Davos-and-COP-attending activists, scientists, 
>>>>> socialogists, political 'scientists', celebrities, and politicians to 
>>>>> 'please, pretty please' at least consider what we say.  It is we, not 
>>>>> they, who speak on behalf of the poor and disenfranchised!
>>>>>  
>>>>> Greg Slater
>>>>>  
>>>>>  
>>>>>> On Feb 12, 2024, at 2:54 PM, Ron Baiman <[email protected] 
>>>>>> <mailto:[email protected]>> wrote:
>>>>>>  
>>>>>> Hi Greg, 
>>>>>>  
>>>>>> Recent modeling suggests that the oceans will gradually release heat to 
>>>>>> the atmosphere but not sure at what rate.
>>>>>>  
>>>>>> This is from the HPAC cooling paper: 
>>>>>> https://essopenarchive.org/doi/full/10.22541/essoar.169755546.65919302/v1
>>>>>>  
>>>>>> <https://essopenarchive.org/doi/full/10.22541/essoar.169755546.65919302/v1>
>>>>>>  
>>>>>> "Failure to begin deployment of direct cooling influence in the very 
>>>>>> near-term necessarily
>>>>>> will lead to greater harm and increased risk, at least until net-zero 
>>>>>> global GHG emissions are
>>>>>> achieved and legacy concentrations of GHGs are removed from the 
>>>>>> atmosphere and oceans.
>>>>>> Recent modeling suggests that, in the absence of direct climate cooling, 
>>>>>> if (anthropogenic and
>>>>>> natural) net-zero emissions were to be achieved after 3667 Gigatons of 
>>>>>> CO2 eq GHG (or 1000
>>>>>> Gigatons of carbon estimated to result in global warming of about 2.0°C) 
>>>>>> were accumulated in
>>>>>> the atmosphere, global warming would remain at roughly 2.0° C for at 
>>>>>> least another 50 years due
>>>>>> to continued thermal rebalancing from legacy ocean warming, even with 
>>>>>> continued ocean uptake
>>>>>> of legacy CO2 from the atmosphere (MacDougall et al., 2020; Hausfather, 
>>>>>> 2021). This suggests
>>>>>> that even after net-zero is achieved, a combination of continued direct 
>>>>>> climate cooling and
>>>>>> drawdown of legacy GHG would be necessary to expeditiously restore and 
>>>>>> regenerate a stable
>>>>>> climate and healthy ecosystem (Schuckmann et al., 2020; Baiman, 2021, 
>>>>>> footnote 9)."
>>>>>>  
>>>>>> Best,
>>>>>> Ron
>>>>>>  
>>>>>> On Mon, Feb 12, 2024 at 3:14 PM Gregory Slater <[email protected] 
>>>>>> <mailto:[email protected]>> wrote:
>>>>>>> 
>>>>>>> Hello All,
>>>>>>> 
>>>>>>> If we managed to reach 'net zero' by, say, 2050, so that, to zeroth 
>>>>>>> order, the concentration of CO2 ceased to increase due to human 
>>>>>>> activities after that time, how would the (mean) ocean temperature 
>>>>>>> respond (over years, decades)?
>>>>>>> 
>>>>>>> I am happy to be directed to any published papers or group threads 
>>>>>>> which 
>>>>>>> discuss this.
>>>>>>> 
>>>>>>> Thanks, in advance, for any help.
>>>>>>> 
>>>>>>> Greg Slater, East Palo Alto, CA
>>>>>>> 
>>>>>>> 
>>>>>>> -- 
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>>>>>>> To unsubscribe from this group and stop receiving emails from it, send 
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>>>>>>> <mailto:healthy-planet-action-coalition%[email protected]>.
>>>>>>> To view this discussion on the web visit 
>>>>>>> https://groups.google.com/d/msgid/healthy-planet-action-coalition/53b39682-29d1-4fc7-a0ee-c3814acdeb50%40gmail.com
>>>>>>>  
>>>>>>> <https://groups.google.com/d/msgid/healthy-planet-action-coalition/53b39682-29d1-4fc7-a0ee-c3814acdeb50%40gmail.com>.
>>>>> 
>>>>>  
>>>>> -- 
>>>>> You received this message because you are subscribed to the Google Groups 
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>>>>> To view this discussion on the web visit 
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>>>>>  
>>>>> <https://groups.google.com/d/msgid/healthy-planet-action-coalition/CD05CB11-5D11-4869-ADCD-197F07468434%40gmail.com?utm_medium=email&utm_source=footer>.
>>>> 
> 

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