Hi All
From http://en.wikipedia.org/wiki/Insolation the variation
of solar input with season and latitude should be shown below.
At midsummer there is about 540 watts per square metre going in to the
North pole compared with 440 going in to the equator. In addition,
around the Arctic there is a very high fraction of low cloud cover, 80
to 90 % compared with around 25% and a much lower boundary layer, about
200 metres so that much less air has to be treated with salt nuclei.
The only requirements for slowing ice melt are mobility of spray vessels
and movement of air or water in a northerly direction.
I was a bit puzzled by Ken's mention of a few billion dollars a year for
marine cloud brightening and would like to collect references on this.
My own figures were based on index linking of the cost of Flower class
corvettes in WW II which were build in similar numbers and suggest a few
billion dollars for a fleet which might last for 20 years or more.
Please can people send me any other cost estimates?
However we can agree that the costs are 'in the noise'.
Stephen
Emeritus Professor of Engineering Design. School of Engineering,
University of Edinburgh, Mayfield Road, Edinburgh EH9 3JL, 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 28/05/2015 22:38, Ronal W. Larson wrote:
List cc Ken, John Nissen, Stephen Salter
Ken’s message re cloud brightening seems to be important . Maybe well
known to those close to the field, but I found much new - especially
between about 6 and 18 minutes in Part 4 (
https://www.youtube.com/watch?v=b3D6mx5SQo8 ) . Nice to see credit
give to Stephen.
Dr. Neukermans and a very few others have done a lot of impressive
work (as volunteers). His speaking style I found convincing
(including all of video #3 - none on cloud brightening). I liked that
some unpromising approaches were also described. Only a little new
(but obviously well justified) money is now being sought.
One question I pose on behalf of John Nissen and others in AMEG is why
the Arctic’s lack of sunlight (mentioned at about the 18 minute mark)
is critical. On an annual basis I believe the insolation is about the
world wide average (as the sun doesn’t set for quite a few months).
Not knowing enough on the whole topic, this technical advance would
seem to be very good news for John/AMEG - if this Arctic solar issue
can still be on the table.
There are quite a few publications on this work, with a few of the
most recent at
https://www.researchgate.net/publication/260755971_Sub-micrometer_salt_aerosol_production_intended_for_marine_cloud_brightening
http://www.economist.com/news/science-and-technology/21635983-scientific-studies-techniques-deliberately-modifying-climate-are
http://articles.latimes.com/2014/mar/04/nation/la-na-climate-engineering-20140305/2
Ron
On May 28, 2015, at 9:04 AM, Ken Caldeira
<[email protected] <mailto:[email protected]>>
wrote:
Five YouTube videos of the 12 May event are available here:
https://www.youtube.com/playlist?list=PL4E3D946BECCF7DE3
The event is described here:
http://www.sri.com/newsroom/events/cafe-scientifique-silicon-valley-sri-two-novel-approaches-mitigating-climate-change
Part 1: Ken on solar geo and strat aerosols:
https://www.youtube.com/watch?v=-Y6p-B-KbiQ
Part 2: Ken on solar geo and strat aerosols:
https://www.youtube.com/watch?v=wo5Y-SPrybE
Part 3: Armand on marine cloud brighening:
https://www.youtube.com/watch?v=ZbpYGwu4KNA
Part 4: Armand on marine cloud brighening:
https://www.youtube.com/watch?v=b3D6mx5SQo8
Part 5: Ken and Armand answer questions:
https://www.youtube.com/watch?v=9KS9Nbe3Wzs
Cafe Scientifique Silicon Valley @ SRI: Reflecting Sunlight to Cool
Earth's Climate: Emulating Volcanoes and Brightening Marine Clouds
May 12, 2015
SRI - Menlo Park, CA
This free Cafe event will feature presentations by two thought
leaders on climate change:
Caldeira and Neukermans
Ken Caldeira (l); Armand Neukermans (r)
*Solar Geoengineering and Climate Change: *Nearly everyone
understands that the most effective way to reduce environmental risk
associated with climate change is to deeply cut greenhouse gas
emissions as soon as possible, yet emissions and atmospheric
concentrations of greenhouse gases continue to increase. If current
emissions trends continue, by the end of this century, nearly every
summer in the tropics will be hotter than the hottest summer yet on
record, raising the possibility of widespread crop failures and
famine. If climate change does prove truly catastrophic, the only
feasible way to cool the Earth rapidly would be to use solar
geoengineering technologies, for example, by emulating the cooling
effects of volcanoes. While it is fairly certain that Earth's climate
can be cooled in this way, it is far less certain whether such
approaches could ever really reduce overall risk and damage. *Dr. Ken
Caldeira*
<http://dge.stanford.edu/labs/caldeiralab/Caldeira_bio.html>, a
senior climate scientist at the Carnegie Institution for Science,
will present the science of solar geoengineering and discuss what
this science might mean for society.
*Marine Cloud Brightening: *The National Academy of Sciences recently
called for research into “geoengineering“. *Dr. Armand
Neukermans* will describe the efforts of a group of retired
scientists and engineers to develop a spray system that might enable
a study of the feasibility of marine cloud brightening (MCB) for
climate cloud studies, as well as possible climate intervention. MCB
aims to increase the reflectivity of low-hanging ocean clouds,
thereby reflecting more sunlight and cooling the planet. This might
be done by increasing the droplet concentration in the clouds by
spraying seawater from oceangoing ships. The proposed systems aims to
create 1015 cloud nuclei from a glass of seawater. MCB ( if ever
needed) might conceivably be used globally or locally (e.g., for
arctic melt shielding, hurricane cooling, reef preservation, or fog
belt restoration).
About the Speakers
*Dr. Ken Caldeira *is a climate scientist working for the Carnegie
Institution for Science, Department of Global Ecology at Stanford
University. He investigates issues related to climate, carbon, and
energy systems. His primary tools are climate and the carbon cycle
models, although he does field work related to ocean acidification.
Dr. Caldeira co-authored a recent National Academies report
<http://www.nap.edu/catalog/18988/climate-intervention-reflecting-sunlight-to-cool-earth>,
/Climate Intervention: Reflecting Sunlight to Cool Earth/. A free PDF
version <http://www.nap.edu/download.php?record_id=18988> is available.
*Dr. Armand Neukermans *has held research and management positions at
KLA-Tencor, Hewlett-Packard, Xerox, and General Electric, and founded
Xros, an optical switch company. He is the author of 40 publications
and the inventor of more than 75 patents in diverse fields. He was
named Silicon Valley “Inventor of the year” in 2001. Since his
retirement, he has been involved in environmental projects, such as
the foundation of the Big Sur Environmental Institute, and in
fostering the causes of social entrepreneurs. He holds EE and ME
degrees from Louvain University, and a Ph.D. in applied physics from
Stanford University.
- See more at:
http://www.sri.com/newsroom/events/cafe-scientifique-silicon-valley-sri-two-novel-approaches-mitigating-climate-change#sthash.S562iCyX.dpuf
_______________
Ken Caldeira
Carnegie Institution for Science
Dept of Global Ecology
260 Panama Street, Stanford, CA 94305 USA
+1 650 704 7212 [email protected]
<mailto:[email protected]>
website: http://dge.stanford.edu/labs/caldeiralab/
blog:http://kencaldeira.org <http://kencaldeira.org/>
@KenCaldeira
My assistant is Dawn Ross <[email protected]
<mailto:[email protected]>>, with access to incoming emails.
Postdoc positions:
https://jobs.carnegiescience.edu/jobs/postdoctoral-opportunity-global-climate-modeling/
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