THE COOLING CONUNDRUM REVERSING CLIMATE CHANGE TO REFREEZE THE ARCTIC

[Andrew Lockley]

https://climateemergencysummit.org/the-cooling-conundrum-event-profile/

THE COOLING CONUNDRUM

REVERSING CLIMATE CHANGE TO REFREEZE THE ARCTIC

With rapidly rising global temperatures, the harm to people and nature is already too great. Signs that we are on the brink of triggering runaway global warming are increasing by the day, as the strain on major ecosystems reaches a new level of stress. Analysis shows that even a zero-emission pathway will not be enough alone to slow warming and avoid further devastation. This points to an urgent need to consider establishing an immediate way to cool the planet. Is reversing climate change a real possibility? What would it take to refreeze the Arctic and Antarctic ice to repair the climate?

David Keith – Professor of Applied Physics, Harvard

Ye Tao – Principal Investigator, Rowland Institute at Harvard

Holly Jean Buck – Science Writer & Analyst 

[Wingenter, Oliver]

It would take 20 nuclear power plants running conventional refrigeration  to cool the Arctic Ocean.and refreeze it.

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[Daniele Visioni]

Hi all,

just pointing out that by chance Walker and the rest of our group have a preprint just published in ESSOAr - and submitted to GRL - about this exact topic, taking a new look at the potential of Arctic SAI.

High-latitude stratospheric aerosol geoengineering can be more effective if injection is limited to spring

Walker Raymond Lee,  Douglas G MacMartin, Daniele Visioni, Ben Kravitz

https://www.essoar.org/doi/10.1002/essoar.10505988.1

Best,

Daniele

////////////////////////////////////////////////////////////
Daniele Visioni, PhD
Post-doctoral Associate
Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY
US phone: (607)-280-0525
e-mail: daniele...@cornell.edu
website: https://dan-visioni.github.io/
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[Adrian Hindes]

@Oliver although that's quite a few nuclear power plants, that's actually not so far out of the realm of possibility.

[Andrew Lockley]

I'm unclear on the proposed mechanism, but any artificial refrigeration simply moves heat around. There is obviously an energy penalty for doing this - and for generating the electricity, in the first place. In short, all the additional thermal energy from the nuclear power plant will ultimately end up as waste heat, in the system you're trying to cool. You can't make a sealed room colder by locking a generator and refrigerator in it - even if that room is the size of a planet. Only by using energy to Accelerate hear transfer to space can anything be achieved. Pumping water through the ice can do this, as can freezing glacier bases to preserve them and their ice-albedo feedback. .

I address some of these issues in my recent paper. 

https://www.sciencedirect.com/science/article/pii/S1674927820300940

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[Adrian Hindes]

Ah of course, the straightforward thermodynamics of it aren't favourable to direct cooling through refrigeration.  

I suppose the only way to make it work would be to transfer the heat to outer space or deep underground. I don't know too much about how heat exchangers or thermal transport works, but having a read of the basal freezing section of your paper, Andrew, I can't imagine anything thermosyphon related would be appropriate for the Arctic.

Aside from glass microspheres then, maybe only marine cloud brightening remains as an ostensibly viable Arctic refreeze technology? It'll be interesting to see what they discuss in the Climate Emergency Summit talk.
-A

[Andrew Lockley]

As per my recent paper, it is promising to pump seawater through the ice (approx 0C), so it freezes in the Arctic winter air (approx -40C). This isn't a new idea, and I think my paper might contain references to earlier work (perhaps Flynn?). 

https://www.sciencedirect.com/science/article/pii/S1674927820300940

Power could indeed be supplied by nuclear power, but wind turbines on barges may be more practical, in terms of scale and redundancy. Alternatively, ice breakers can create open water, which quickly freezes. The jumble of broken ice can also possibly catch snow and resist melting. This idea isn't in the paper, but was discussed on the list (perhaps Veli?)

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[Douglas MacMartin]

Adrian – your list of ostensibly viable should include SAI too, as was pointed out earlier on this same thread.  In principle one could inject SO2 or other in the spring at high latitude (and indeed, that may be the most economically viable, technologically achievable near-term approach – and to be clear I wouldn’t advocate doing anything simply because it’s cheap, simply pointing it out).  Re MCB, I don’t know if there are sufficient susceptible clouds at high latitudes to do something focused on the Arctic, vs using it to cool lower latitudes and thus cool the Arctic by reducing heat transport – which, of course, if your sole metric is freezing the Arctic, would work.   For any of these things one has to look at all of the impacts, and the science is still pretty immature beyond recognizing the overall ability to cool.

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[Peter Flynn]

I think that one way to get heat into space is to get it into the atmosphere from the ocean. Creating incremental ice by putting water on the surface of existing ice, or “seeding” ice formation by a spray during cold periods in the Arctic, transfer heat from water to air. (Both these ice formation technologies have a long history in the north. A warmer atmosphere radiates more heat into space, with a temperature dependence of T^4, where T is the absolute temperature.

 

Peter Flynn

 

Peter Flynn, P. Eng., Ph. D.

Emeritus Professor and Poole Chair in Management for Engineers

Department of Mechanical Engineering

University of Alberta

Edmonton, Alberta, Canada

1 928 451 4455

peter...@ualberta.ca

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[Andrew Lockley]

My understanding is that the transparent atmosphere does not radiate efficiently. The sea surface has a low albedo, and is thus a very effective radiator. It's also at a very high temperature, compared to the surrounding air and ice surface. 

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