Hi All
I think that Doug is being over cautious. Twomey's work used physical
observations of real clouds and seems robust to me. The meteorological
results can were checked and confirmed from ship-track observations by
Andrew Ackerman. The optics can be checked with jars of glass balls.
Much of the cloud physics could be checked in a cloud chamber. Several
reputable climate models are in fairly good agreement. I do not know of
any which do not. The Discovery Channel experiment at Laaiplek worked
far better than anyone expected.
I would argue that the biggest uncertainty is the Altersjkaer paper
suggesting that Aitken mode salt residues warm instead of cooling. We
could increase confidence with a single, mobile spray source with
mono-disperse spray used for a few months in a wide range of conditions.
Using coded modulation with the best climate models would give us the
information we need to get desirable precipitation patterns. The cost of
this work for marine cloud brightening is well below that of a single
international climate conference.
If there are show stoppers we should identify them as soon as possible.
The longer development and experiments take will take the earlier we
should start. Future generations might not forgive us for the delay.
Stephen
Emeritus Professor of Engineering Design. School of Engineering,
University of Edinburgh, Mayfield Road, Edinburgh EH9 3DW, Scotland
[email protected], Tel +44 (0)131 650 5704, Cell 07795 203 195,
WWW.homepages.ed.ac.uk/shs, YouTube Jamie Taylor Power for Change
On 04/11/2017 15:43, Douglas MacMartin wrote:
Both SAI and MCB probably need of order of 20 years of research before we could make
reasonably informed decisions; both have a long list of unknowns. (In the case of MCB,
we don't even really know if it "works" in any meaningful sense of the word,
because cloud-aerosol interactions are too uncertain today, so we really don't know
whether there is a useful fraction of cloud meteorological conditions in which the albedo
is significantly enhanced. We should all really really hope that it doesn't work very
well, because if it doesn't, that means the indirect aerosol effect is smaller than
current best guess and climate sensitivity will be on the low end...)
(And, of course, at the current level of worldwide funding, that "20" above is
probably off by a few orders of magnitude.)
-----Original Message-----
From: [email protected] [mailto:[email protected]]
On Behalf Of Michael Hayes
Sent: Saturday, November 04, 2017 10:00 AM
To: geoengineering <[email protected]>
Subject: Re: [geo] Can anyone offer a CE perspective on this SLR article?
Holly and List,
The use of sulfur needs proper polar field level testing. Testing is planned
yet may not be done in areas prone to Polar Stratospheric Cloud formation. Time
of the season is also of the essence for testing.
Until that is done, SAI has a large question to answer; in general terms.
MCB, used in key areas, is a critical first step. There should be no deflection
at that engineering level. Once MCB paves the way, other marine capable systems
can gain traction.
What marine engineering minded person or institution would not give Steven's
word heavy weight? This is a marine issue.
--
You received this message because you are subscribed to the Google Groups
"geoengineering" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
Visit this group at https://groups.google.com/group/geoengineering.
For more options, visit https://groups.google.com/d/optout.
The University of Edinburgh is a charitable body, registered in
Scotland, with registration number SC005336.
--
You received this message because you are subscribed to the Google Groups
"geoengineering" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
Visit this group at https://groups.google.com/group/geoengineering.
For more options, visit https://groups.google.com/d/optout.
