Potential "bottom up" cooling needs after net-zero?

[Ron Baiman]

Dear Colleagues,

In lieu of the recent research suggesting that we may be in for a warming plateau of at least 50 years after net-zero due to the roughly offsetting effects of continued ocean uptake of GHG and release of latent heat accumulated in the ocean over many decades of warming (see: https://www.carbonbrief.org/explainer-will-global-warming-stop-as-soon-as-net-zero-emissions-are-reached/) does anyone know of modeling research on the potential need for "bottom up" direct cooling at the point where the "warming from below" from the ocean is greater than "the warming from above" from the sun?

I'm thinking of techniques such as OTEC and WOHC (to harvest energy from and cool the oceans) as  well as CCT (to "open up" the clouds so as to release more heat that has already been accumulated)?

Thank you!

Ron Baiman

[Ron Baiman]

For more on the OTEC, WOXON, and CCT cooling methods see cooling paper linked to here: https://www.healthyplanetaction.org/

[Ron Baiman]

Thank you for the question Michael.

My understanding is that the global warming impact of the "bottom up" heat from the ocean in the models  is closely related to the level of offsetting cooling from natural (and other) GHG draw down from the atmosphere and the Oceans. In other words, rates of natural GHG  uptake in the Ocean, and draw down from the atmosphere and ocean through other means, are key elements in the long term modeling that could presumably also be impacted by applying "bottom up" and "opening up" cooling techniques. The question is whether there is any modeling of the balancing levels and potential time scales for the GHG processes that would give some idea of the needs and types of potentially necessary cooling processes.

Ron Baiman

Ron

On Mon, Feb 20, 2023 at 4:48 PM Michael Hayes <electro...@gmail.com> wrote:

Ron, how does this relate to CDR?

[Ron Baiman]

Last sentence edit:

*The question is whether there is any modeling of the balancing levels and potential time scales for the GHG processes that would give some idea of the needs and types of potentially necessary cooling and GHG draw down processes.*

[Ron Baiman]

Dear Michael,

I think I understand your concerns, but I don't agree that this topic is out of bounds for the CDR list as it in my view clearly includes CDR issues (and I've received private feedback from CDR  focused folks on this list saying that they agree with me.)

For example how much GHG drawdown will be necessary to actually cool the planet if net-zero (both anthropogenic and natural) can be achieved as (based on the modeling) restoring 350 ppm will not be adequate due to continued heating from the ocean, and if more GHG is drawn down that could hypothetically create a problem of excess cooling if the excess ocean heat eventually dissipates? The problem is one of trying to adjust a flow balance like global warming equilibrium with stock variables (GHG in the atmosphere and CO2 in the ocean) when other factors (cumulative ocean surface warming) are also at play. It seems to me that the new modeling results suggest that "temporary" cooling measures could be necessary and/or more effective than CDR in the future even if some (obviously not including myself) believe that they are not called for right now?

In any case rather than this rather pointless debate, may I suggest that folks who are not interested in this thread can just ignore it?

Best,

Ron

On Mon, Feb 20, 2023 at 6:59 PM Michael Hayes <electro...@gmail.com> wrote:

Dear Ron, et al.

Generally speaking, cooling is clearly an important STEM, policy, and economic subject. Specifically, I myself would like to see an urgent research and deployment focus upon producing nothing but a vast amount of sea ice as that alone can likely help many critical biogeochemical needs which include helping the planetary C cycle, it's all connected.

With that said and in defense of a highly focused CDR posting practice within the CDR Google Group, the primary benefit of a very specific CDR focus is that it helps build high level action oriented collaborative efforts around well defined STEM, policy, and socioeconomic goals along with helping build specific RDD&D funding paths.

At the theoretical level, a broad spectrum effort of linking what is now an almost uncountable number of innovative ideas concerning mitigation and adaptation, or the 'GE' model of discussion, is likely to overwhelm any action oriented collaboration of any size, of any complexity, or of any level of funding. As such, action on many of the individual concepts within such a broad 'GE' style STEM basket becomes much harder at almost all meaningful levels. The limiting of the STEM, policy, and socioeconomic discussions to CDR has seemingly managed to avoid such a form of paralysis, and this CDR centric Google Group likely has helped provide the needed focus to do so by itself staying focused. 

Best regards 

[Stephen Salter]

Hi All

If you pump cold water up it will initially sink very quickly and then spread out at the depth where the temperature is the same.

If you pump warm surface water down it will initially rise quickly and spread out when it gets to the depth still well below the surface with the same density.

One advantage of down pumping it that there is a slight positive pressure inside the down tube which mean that it can be made with very cheap 250 micron polythene in gentle tension.

Small scale 1/100 scale models have been tank tested and filmed by Discovery Channel.  A key finding is that the fraction of the wave energy that gets through the front wall travels across to the back wall and gets a second gulp of water by sucking it in.    I have designs for making very large floppy structures.

A paper written for hurricane moderation is attached with apologies to those of you who have already seen it.  I think that for hurricane moderation marine cloud brightening allows better control of position than the idea of circulation round a gyre.  However the use for destratification may be useful.  

Stephen

 

Emeritus Professor of Engineering Design

School of Engineering

University of Edinburgh

Mayfield Road

Edinburgh EH9 3DW

Scotland

0131 650 5704 or 0131 662 1180

YouTube Jamie Taylor Power for Change

 

 

 

 

From: noac-m...@googlegroups.com <noac-m...@googlegroups.com> On Behalf Of Ron Baiman
Sent: 20 February 2023 23:23
To: Michael Hayes <electro...@gmail.com>
Cc: geoengineering <geoengi...@googlegroups.com>; healthy-planet-action-coalition <healthy-planet-...@googlegroups.com>; Planetary Restoration <planetary-...@googlegroups.com>; 'Eelco Rohling' via NOAC Meetings <noac-m...@googlegroups.com>; Healthy Climate Alliance <healthy-clim...@googlegroups.com>; Carbon Dioxide Removal <carbondiox...@googlegroups.com>; Jim Baird <jim....@gwmitigation.com>; Achim Hoffmann <ac...@woxon.com>; David Mitchell <David.M...@dri.edu>; Tom Goreau <gor...@globalcoral.org>; Andrew Lockley <andrew....@gmail.com>
Subject: Re: Potential "bottom up" cooling needs after net-zero?

 

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[Ron Baiman]

Thank you Stephen. As I recall the version of OTEC that Jim Baird and Greg Rau addressed in their paper (cited in the cooling document I posted) harvests and circulates (with a low boiling point working fluid) heat rather than water.  The ocean surface heat that is not harvested to produce energy (replacing existing energy production - per Jim's post) is released below the Ocean surface where it is estimated to take more than a couple of centuries  to come back up to the surface again. At scale this is estimated to produce significant long-term global cooling somewhat analogous to the late 90's early 2000's hiatus global warming that resulted from temporary ocean currents that caused warm water down welling and cool water up welling during that period (as I recall).

Ron Baiman