I don't think hydrosols will behave like CNN, in terms of their
radiative properties. As I understand it, CCN act to brighten existing
cloud cover. They won't, therefore, work on cloudless days. Likely,
relative efficacy will depend on whether acute or chronic thermal
stress is most important. Furthermore, hydrosols will cause a lasting
increase in diffuse radiation. In terrestrial models, this has
impacted NPP.
I'm no expert on this niche - but that's my initial thoughts.
Hope it helps
A
On 24 April 2017 at 02:00, Ken Caldeira <[email protected]
<mailto:[email protected]>> wrote:
Coral bleaching is also associated with stress from sunlight,
coupled with high temperatures, etc.
Wikipedia: Some scientists consider bleaching a poorly-understood
type of "stress" related to high irradiance
<https://en.wikipedia.org/wiki/Irradiance>; environmental factors
like sediments, harmful chemicals, and freshwater; and high or low
water temperatures.^[1]
<https://en.wikipedia.org/wiki/Coral_bleaching#cite_note-agu-1>
https://en.wikipedia.org/wiki/Coral_bleaching
<https://en.wikipedia.org/wiki/Coral_bleaching>
See section 4.1.2 of this document:
https://www.coris.noaa.gov/activities/reef_managers_guide/reef_managers_guide_ch4.pdf
<https://www.coris.noaa.gov/activities/reef_managers_guide/reef_managers_guide_ch4.pdf>
It is common to see the sun-exposed tops of coral colonies with
severe bleaching, with the shaded sides doing reasonably well.
Deflecting sunlight away from the ocean waters would likely have
direct protective properties beyond the cooling effect.
http://www.natureworldnews.com/articles/18949/20151224/cloudy-waters-shade-corals-excess-sunlight-helping-survive-climate-change.htm
<http://www.natureworldnews.com/articles/18949/20151224/cloudy-waters-shade-corals-excess-sunlight-helping-survive-climate-change.htm>
Ken Caldeira
Carnegie Institution for Science
Dept of Global Ecology
260 Panama St
Stanford CA 94305 USA
+1 650 704 7212 <tel:%28650%29%20704-7212>
http://CarnegieEnergyInnovation.org
<http://CarnegieEnergyInnovation.org>
http://dge.stanford.edu/labs/caldeiralab
<http://dge.stanford.edu/labs/caldeiralab>
Assistant, with access to incoming emails: Jess Barker
[email protected] <mailto:[email protected]>
On Sun, Apr 23, 2017 at 3:39 PM, Russell Seitz
<[email protected] <mailto:[email protected]>> wrote:
Dear Stephen:
I hasten to point out that your analysis of cloud cooling
of 23km3 from the top down applies equally to microbubble
cooling SRM from the bottom up.
Last year, after meeting with UNEP coral conservtionist Tom
Goreau I visiited several reef damage redmediation sites in
the Grenadines, where though emphasis has been on replanting
, widespread bleaching has also led to interest in sea surface
cooling.
As bothh ocean and lake models suggest the fresh water
techniques we are developing to curb fresh water reservoir
evaporation can realitstically achieve coolings of 5 K or
more, and the energy cost per hectare is reckoned to be a
kilowatt or less, a continouous multimegawatt reduction in
solar load may be an afforable alterative to your admittedly
better developed cloud nucleation work.
It shoud be noted that many South China Sea reefs face
thermal stresses approaching those of the GBR as well - in
both cases ecologists should explore the addvantages and
hazards of brightening the water instead of dimming the sun.
Best regards
Russsell Seitz
Senior Fellow
The Climate Institute
On Saturday, April 22, 2017 at 6:18:33 AM UTC-4, Stephen
Salter wrote:
Hi All
Ken says there might not be enough clouds to save the
barrier reef.
Below should be a map from Kari Alterskjaer from
doi:10.5194/acp-12-2795-2012 showing how good different
regions are through the seasons.
The very best red ones of California, Peru and Namibia
score 0.12 but the much larger white areas are 0.085 show
the best are only 40% better.
Further more the life time of nuclei under clear skies
will be longer so a high cloud fraction is less
important. We should not let the best become the enemy
of the quite good.
I got some data about flow rates into the Barrier Reef
region from a PhD thesis by Severine Choukroun from
https://researchonline.jcu.edu.au/24024/
<https://researchonline.jcu.edu.au/24024/>
The key number is 23 km3 per day. If anyone can give me
other numbers please do. If following Kohler you believe
that the right size of mono-disperse spray will give a
high nucleation fraction and that some other assumptions
are reasonable then the calculations below will tell you
how many spray vessels would be needed to cool the Barrier
Reef.
However another paper from Norway
DOI:10.1029/2010JD014015
suggests that my mono-disperse spray assumption does
matter because spray with the Aitken mode size
distribution works in the wrong direction.
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 <tel:+44%20131%20650%205704>, Cell 07795
203 195, WWW.homepages.ed.ac.uk/shs
<http://WWW.homepages.ed.ac.uk/shs>, YouTube Jamie Taylor
Power for Change
On 22/04/2017 08:31, Andrew Lockley wrote:
https://www.technologyreview.com/s/604211/scientists-consider-brighter-clouds-to-preserve-the-great-barrier-reef/
<https://www.technologyreview.com/s/604211/scientists-consider-brighter-clouds-to-preserve-the-great-barrier-reef/>
# A scientist surveys bleaching damage on the Great Barrier
Reef.
# TANE SINCLAIR-TAYLOR | ARC CENTRE OF EXCELLENCE CORAL
REEF STUDIES
Sustainable Energy
<http://t.sidekickopen68.com/e1t/c/5/f18dQhb0S7lC8dDMPbW2n0x6l2B9nMJW7t5XZs2zqkS-W7gbG387fZBS-W7fsH1M56dykWf7ppmYC02?t=https%3A%2F%2Fwww.technologyreview.com%2Ftopic%2Fsustainable-energy%2F&si=5245033433530368&pi=50d1d72e-c841-4795-c691-bdbd028e2fb4>
Scientists Consider Brighter Clouds to Preserve the
Great Barrier Reef
As bleaching devastates the critical ecosystem for a
second year in a row, marine scientists are getting
desperate.
* by James Temple
<http://t.sidekickopen68.com/e1t/c/5/f18dQhb0S7lC8dDMPbW2n0x6l2B9nMJW7t5XZs2zqkS-W7gbG387fZBS-W7fsH1M56dykWf7ppmYC02?t=https%3A%2F%2Fwww.technologyreview.com%2Fprofile%2Fjames-temple%2F&si=5245033433530368&pi=50d1d72e-c841-4795-c691-bdbd028e2fb4>
*
* April 20, 2017
Agroup of Australian marine scientists believe that
altering clouds might offer one of the best hopes for
saving the Great Barrier Reef.
For the last six months, researchers at the Sydney
Institute of Marine Science and the University of Sydney
School of Geosciences have been meeting regularly to
explore the possibility of making low-lying clouds off
the northeastern coast of Australia more reflective in
order to cool the waters surrounding the world’s biggest
coral reef system.
During the last two years, the Great Barrier Reef has
been devastated by wide-scale bleaching, which occurs as
warm ocean waters cause corals to discharge the algae
that live in symbiosis with them. Last year, as El Niño
events cranked up ocean temperatures, at least 20 percent
of the reef died and more than 90 percent of it was damaged.
The Australian researchers took a hard look at a number
<http://t.sidekickopen68.com/e1t/c/5/f18dQhb0S7lC8dDMPbW2n0x6l2B9nMJW7t5XZs2zqkS-W7gbG387fZBS-W7fsH1M56dykWf7ppmYC02?t=https%3A%2F%2Fwww.theguardian.com%2Fenvironment%2F2017%2Fapr%2F07%2Fplan-cold-water-barrier-reef-stop-bleaching&si=5245033433530368&pi=50d1d72e-c841-4795-c691-bdbd028e2fb4>
of
potential ways
<http://t.sidekickopen68.com/e1t/c/5/f18dQhb0S7lC8dDMPbW2n0x6l2B9nMJW7t5XZs2zqkS-W7gbG387fZBS-W7fsH1M56dykWf7ppmYC02?t=http%3A%2F%2Fwww.newyorker.com%2Fmagazine%2F2016%2F04%2F18%2Fa-radical-attempt-to-save-the-reefs-and-forests&si=5245033433530368&pi=50d1d72e-c841-4795-c691-bdbd028e2fb4>
to
preserve the reefs. But at this point, making clouds more
reflective looks like the most feasible way to protect an
ecosystem that stretches across more than 130,000 square
miles, says Daniel Harrison, a postdoctoral research
associate with the Ocean Technology Group at the
University of Sydney. “Cloud brightening is the only
thing we’ve identified that’s scalable, sensible, and
relatively environmentally benign,” he says.
Bleached corals on the Great Barrier Reef.
ED ROBERTS/TETHYS IMAGES | ARC CENTRE OF EXCELLENCE CORAL
REEF STUDIES
They’re one of several research groups that have started
to explore whether cloud brightening, generally discussed
as a potential tool to alter the climate as a whole,
could be applied in more targeted ways. All the
scientists involved stress that the research is in its
infancy. No one has tested a system for cloud brightening
at all, much less in geographically focused applications.
British scientist John Latham first proposed the idea as
a potential way of controlling global warming
<http://t.sidekickopen68.com/e1t/c/5/f18dQhb0S7lC8dDMPbW2n0x6l2B9nMJW7t5XZs2zqkS-W7gbG387fZBS-W7fsH1M56dykWf7ppmYC02?t=http%3A%2F%2Fwww.nature.com%2Fnature%2Fjournal%2Fv347%2Fn6291%2Fabs%2F347339b0.html&si=5245033433530368&pi=50d1d72e-c841-4795-c691-bdbd028e2fb4>
in
/Nature/ nearly 30 years ago. The theory is that fleets
of ships could spray tiny salt particles, generated from
sea water, toward the low-lying marine clouds that hug
the coasts of several continents. That would provide the
nuclei needed to induce additional droplet formation,
expanding the total surface area of the clouds. The
resulting dense, white clouds should reflect more heat
back into space. A 2012 study led by Latham at the
University of Manchester found that the approach could
offset the heating that would result if carbon dioxide
doubled in
<http://t.sidekickopen68.com/e1t/c/5/f18dQhb0S7lC8dDMPbW2n0x6l2B9nMJW7t5XZs2zqkS-W7gbG387fZBS-W7fsH1M56dykWf7ppmYC02?t=http%3A%2F%2Frsta.royalsocietypublishing.org%2Fcontent%2F370%2F1974%2F4217&si=5245033433530368&pi=50d1d72e-c841-4795-c691-bdbd028e2fb4>
the
atmosphere.
The Marine Cloud Brightening Project, a collaboration
between a group of Silicon Valley researchers
<http://t.sidekickopen68.com/e1t/c/5/f18dQhb0S7lC8dDMPbW2n0x6l2B9nMJW7t5XZs2zqkS-W7gbG387fZBS-W7fsH1M56dykWf7ppmYC02?t=http%3A%2F%2Fwww.sfgate.com%2Fscience%2Farticle%2FLooking-to-sky-to-fight-climate-change-4170475.php&si=5245033433530368&pi=50d1d72e-c841-4795-c691-bdbd028e2fb4>
and
University of Washington climate scientists, has done the
most advanced work on the idea to date. The team in
Sunnyvale, California, has spent the last seven years
developing a nozzle that they believe can spray salt
particles of just the right size and quantity to alter
the clouds. They’re attempting to raise several million
dollars to build full-scale sprayers, in hopes of
eventually conducting small-scale field trials at some
flat point along the Pacific coastline—ideally a place
with onshore winds, low-lying clouds, and open-minded
neighbors.
The Marine Cloud Brightening Project's nozzle sprays a
fine mist of tiny salt particles.
JAMES TEMPLE
They’re among a handful of researchers looking to conduct
limited outdoor experiments to explore the feasibility
and risks of such approaches (see “The Growing Case for
Geoengineering
<http://t.sidekickopen68.com/e1t/c/5/f18dQhb0S7lC8dDMPbW2n0x6l2B9nMJW7t5XZs2zqkS-W7gbG387fZBS-W7fsH1M56dykWf7ppmYC02?t=https%3A%2F%2Fwww.technologyreview.com%2Fs%2F604081%2Fthe-growing-case-for-geoengineering%2F%3Fset%3D604205&si=5245033433530368&pi=50d1d72e-c841-4795-c691-bdbd028e2fb4>”).
But while the prospect of using geoengineering to ease
global warming on a large scale poses intractable
governance issues, using the technology to address a more
localized problem could be more feasible, at least
politically.
Coral reefs are crucial parts of the ocean ecosystem,
providing hunting grounds and homes for thousands of
species. They also generate nearly $200 billion in
economic value annually, through tourism, fisheries, and
other activity, according to one study
<http://t.sidekickopen68.com/e1t/c/5/f18dQhb0S7lC8dDMPbW2n0x6l2B9nMJW7t5XZs2zqkS-W7gbG387fZBS-W7fsH1M56dykWf7ppmYC02?t=https%3A%2F%2Fwww.eurekalert.org%2Fpub_releases%2F2009-10%2Fd-wac101509.php&si=5245033433530368&pi=50d1d72e-c841-4795-c691-bdbd028e2fb4>.
Reefs, however, have been hard hit worldwide by ocean
acidification, pollution, overfishing, and other
environmental stresses. The Great Barrier Reef has shrunk
dramatically during the last three decades
<http://t.sidekickopen68.com/e1t/c/5/f18dQhb0S7lC8dDMPbW2n0x6l2B9nMJW7t5XZs2zqkS-W7gbG387fZBS-W7fsH1M56dykWf7ppmYC02?t=http%3A%2F%2Fwww.bbc.com%2Fnews%2Fscience-environment-19800253&si=5245033433530368&pi=50d1d72e-c841-4795-c691-bdbd028e2fb4>.
That makes it increasingly urgent to seriously explore
ways of preserving the reefs, even “fairly out-there,
grand schemes,” Harrison says. Next month, he plans to
start computer climate modeling to explore
<http://t.sidekickopen68.com/e1t/c/5/f18dQhb0S7lC8dDMPbW2n0x6l2B9nMJW7t5XZs2zqkS-W7gbG387fZBS-W7fsH1M56dykWf7ppmYC02?t=http%3A%2F%2Fmyerfoundation.org.au%2Fnews%2F2017-myer-innovation-fellows-announced%2F&si=5245033433530368&pi=50d1d72e-c841-4795-c691-bdbd028e2fb4>
whether
cloud brightening could make a big enough temperature
difference to help. The group plans to collaborate on the
research with the Marine Cloud Brightening Project team.
Should scientists try to save the Great Barrier
Reef by brightening the clouds?
Tell us what you think.
<http://t.sidekickopen68.com/e1t/c/5/f18dQhb0S7lC8dDMPbW2n0x6l2B9nMJW7t5XZs2zqkS-W7gbG387fZBS-W7fsH1M56dykWf7ppmYC02?t=https%3A%2F%2Fwww.technologyreview.com%2Fs%2F604211%2Fscientists-consider-brighter-clouds-to-preserve-the-great-barrier-reef%2F%23comments&si=5245033433530368&pi=50d1d72e-c841-4795-c691-bdbd028e2fb4>
Coral reefs aren’t the only ecosystem that some
scientists believe might need help from geoengineering.
Researchers at the University of California, the Carnegie
Institution, Stanford University, and Oregon State
University have begun a larger project
<http://t.sidekickopen68.com/e1t/c/5/f18dQhb0S7lC8dDMPbW2n0x6l2B9nMJW7t5XZs2zqkS-W7gbG387fZBS-W7fsH1M56dykWf7ppmYC02?t=http%3A%2F%2Fwww.fogsci.com%2F&si=5245033433530368&pi=50d1d72e-c841-4795-c691-bdbd028e2fb4>
exploring,
among other things, how climate change is affecting or
will affect the last remaining stands of coast redwoods.
They're the world's tallest trees, and rely on coastal
fog for around half of their moisture. But Northern
California fog levels have dropped more than 30 percent
<http://t.sidekickopen68.com/e1t/c/5/f18dQhb0S7lC8dDMPbW2n0x6l2B9nMJW7t5XZs2zqkS-W7gbG387fZBS-W7fsH1M56dykWf7ppmYC02?t=http%3A%2F%2Fwww.pnas.org%2Fcontent%2F107%2F10%2F4533.full&si=5245033433530368&pi=50d1d72e-c841-4795-c691-bdbd028e2fb4>
since
the early 20th century, a decline linked to urbanization
and climate change. The impact has been limited to date,
but fear is growing that these old-growth stands could be
wiped out if the trends accelerate.
Elliott Campbell, an associate professor of environmental
engineering at UC Merced, says the group has held early
talks with the Marine Cloud Brightening Project about
whether the technique could generate more low-lying
clouds to help feed moisture to the redwoods. “If we
could artificially produce fog on summer mornings, and
that could help us buy the redwoods more time as we shift
to a less carbon-intensive economy, that’s potentially a
good thing,” Campbell says.
Aerial view of a bleached portion of the Great Barrier Reef.
ARC CENTRE OF EXCELLENCE CORAL REEF STUDIES
Ken Caldeira
<http://t.sidekickopen68.com/e1t/c/5/f18dQhb0S7lC8dDMPbW2n0x6l2B9nMJW7t5XZs2zqkS-W7gbG387fZBS-W7fsH1M56dykWf7ppmYC02?t=https%3A%2F%2Fwww.technologyreview.com%2Fs%2F543916%2Fstop-emissions%2F&si=5245033433530368&pi=50d1d72e-c841-4795-c691-bdbd028e2fb4>,
a prominent climate scientist at the Carnegie Institution
who has modeled the potential of cloud brightening, says
the idea of localized geoengineering is worth exploring.
But he’s not convinced that cloud brightening could
produce a substantial climate effect at such a limited
level. Below a certain geographic footprint, probably
around 10,000 square miles, it might be difficult to
produce a big enough change in cloud density to add up to
much of a difference, he says. He’s specifically
skeptical that it would work at the Great Barrier Reef.
“I just don’t think there are enough clouds of the right
type there that would be susceptible to marine cloud
brightening,” he says.
The University of Sydney’s Harrison is aware of the
concerns Caldeira raises and intends to look at these
issues closely in his feasibility research. But at a
first pass, he believes there could be sufficient marine
clouds to help preserve the Great Barrier Reef.
In any case, he hopes so, because nothing else looks
particularly promising.
Tech Obsessive?
Become an Insider to get the story behind the story — and
before anyone else.
Subscribe today
<http://t.sidekickopen68.com/e1t/c/5/f18dQhb0S7lC8dDMPbW2n0x6l2B9nMJW7t5XZs2zqkS-W7gbG387fZBS-W7fsH1M56dykWf7ppmYC02?t=https%3A%2F%2Fssl.drgnetwork.com%2Fecom%2FMTR%2Fapp%2Flive%2Fsubscriptions%3Forg%3DMTR%26publ%3DTR%26key_code%3DPRSPRIS%26type%3DS&si=5245033433530368&pi=50d1d72e-c841-4795-c691-bdbd028e2fb4>
*
*
*
*
*
*
*
*
Tagged
Ken Caldeira
<http://t.sidekickopen68.com/e1t/c/5/f18dQhb0S7lC8dDMPbW2n0x6l2B9nMJW7t5XZs2zqkS-W7gbG387fZBS-W7fsH1M56dykWf7ppmYC02?t=https%3A%2F%2Fwww.technologyreview.com%2Fg%2Fken-caldeira%2F&si=5245033433530368&pi=50d1d72e-c841-4795-c691-bdbd028e2fb4>,geoengineering
<http://t.sidekickopen68.com/e1t/c/5/f18dQhb0S7lC8dDMPbW2n0x6l2B9nMJW7t5XZs2zqkS-W7gbG387fZBS-W7fsH1M56dykWf7ppmYC02?t=https%3A%2F%2Fwww.technologyreview.com%2Fg%2Fgeoengineering%2F&si=5245033433530368&pi=50d1d72e-c841-4795-c691-bdbd028e2fb4>,
clouds
<http://t.sidekickopen68.com/e1t/c/5/f18dQhb0S7lC8dDMPbW2n0x6l2B9nMJW7t5XZs2zqkS-W7gbG387fZBS-W7fsH1M56dykWf7ppmYC02?t=https%3A%2F%2Fwww.technologyreview.com%2Fg%2Fclouds%2F&si=5245033433530368&pi=50d1d72e-c841-4795-c691-bdbd028e2fb4>,Great
Barrier Reef
<http://t.sidekickopen68.com/e1t/c/5/f18dQhb0S7lC8dDMPbW2n0x6l2B9nMJW7t5XZs2zqkS-W7gbG387fZBS-W7fsH1M56dykWf7ppmYC02?t=https%3A%2F%2Fwww.technologyreview.com%2Fg%2Fgreat-barrier-reef%2F&si=5245033433530368&pi=50d1d72e-c841-4795-c691-bdbd028e2fb4>,
Daniel Harrison
<http://t.sidekickopen68.com/e1t/c/5/f18dQhb0S7lC8dDMPbW2n0x6l2B9nMJW7t5XZs2zqkS-W7gbG387fZBS-W7fsH1M56dykWf7ppmYC02?t=https%3A%2F%2Fwww.technologyreview.com%2Fg%2Fdaniel-harrison%2F&si=5245033433530368&pi=50d1d72e-c841-4795-c691-bdbd028e2fb4>,
Australia
<http://t.sidekickopen68.com/e1t/c/5/f18dQhb0S7lC8dDMPbW2n0x6l2B9nMJW7t5XZs2zqkS-W7gbG387fZBS-W7fsH1M56dykWf7ppmYC02?t=https%3A%2F%2Fwww.technologyreview.com%2Fg%2Faustralia%2F&si=5245033433530368&pi=50d1d72e-c841-4795-c691-bdbd028e2fb4>
James Temple
James Temple
<http://t.sidekickopen68.com/e1t/c/5/f18dQhb0S7lC8dDMPbW2n0x6l2B9nMJW7t5XZs2zqkS-W7gbG387fZBS-W7fsH1M56dykWf7ppmYC02?t=https%3A%2F%2Fwww.technologyreview.com%2Fprofile%2Fjames-temple%2F&si=5245033433530368&pi=50d1d72e-c841-4795-c691-bdbd028e2fb4>Senior
Editor, Energy
I am the senior editor for energy at /MIT Technology
Review/. I’m focused on renewable energy and the use of
technology to combat climate change. Previously, I was a
senior director at the /Verge/, deputy managing editor at
/Recode/, and columnist at the /San Francisco Chronicle/.
When I’m not writing about energy and climate change, I’m
often hiking with my dog or shooting video of California
landscapes.
--
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
<https://groups.google.com/group/geoengineering>.
For more options, visit
https://groups.google.com/d/optout
<https://groups.google.com/d/optout>.
--
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]
<mailto:[email protected]>.
To post to this group, send email to
[email protected]
<mailto:[email protected]>.
Visit this group at
https://groups.google.com/group/geoengineering
<https://groups.google.com/group/geoengineering>.
For more options, visit https://groups.google.com/d/optout
<https://groups.google.com/d/optout>.
--
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]
<mailto:[email protected]>.
To post to this group, send email to
[email protected]
<mailto:[email protected]>.
Visit this group at https://groups.google.com/group/geoengineering
<https://groups.google.com/group/geoengineering>.
For more options, visit https://groups.google.com/d/optout
<https://groups.google.com/d/optout>.
--
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]
<mailto:[email protected]>.
To post to this group, send email to [email protected]
<mailto:[email protected]>.
Visit this group at https://groups.google.com/group/geoengineering.
For more options, visit https://groups.google.com/d/optout.
