interview with me in Neue Zurcher Zeitung (translated into German)
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Ken Caldeira
Jun 28, 2012, 1:27:06 AM6/28/12
to geoengineering
pdf attached.
http://www.nzz.ch/wissen/wissenschaft/sonnenschutz-fuer-die-erde-1.17282213
_______________
Ken Caldeira
Carnegie Institution for Science
Dept of Global Ecology
260 Panama Street, Stanford, CA 94305 USA
http://dge.stanford.edu/labs/caldeiralab @kencaldeira
Currently visiting Institute for Advanced Sustainability Studies (IASS)
http://dge.stanford.edu/labs/caldeiralab @kencaldeira
Currently visiting Institute for Advanced Sustainability Studies (IASS)
and Potsdam Institute for Climate Impact Research (PIK) in Potsdam, Germany.
Stephen Salter
Jun 28, 2012, 11:30:39 AM6/28/12
to geoengi...@googlegroups.com
Ken
It should follow from your argument about the land-sea temperature difference reducing precipitation on land that a technique which had the initial effect of cooling the sea would be more attractive. If it were also possible to have a frequency response shorter than the monsoon cycle we could play useful tricks about the phase of operations relative to the monsoon season.
Stephen
It should follow from your argument about the land-sea temperature difference reducing precipitation on land that a technique which had the initial effect of cooling the sea would be more attractive. If it were also possible to have a frequency response shorter than the monsoon cycle we could play useful tricks about the phase of operations relative to the monsoon season.
Stephen
Emeritus Professor of Engineering Design Institute for Energy Systems School of Engineering Mayfield Road University of Edinburgh EH9 3JL Scotland Tel +44 131 650 5704 Mobile 07795 203 195 www.see.ed.ac.uk/~shs
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Simone Tilmes
Jun 28, 2012, 12:37:33 PM6/28/12
to geoengi...@googlegroups.com
Dear Ken,
in the article you stated that Mt Pinatubo is assumed to result in a
global cooling of about 0.5 degree. It is also stated in the text of the
article that the amount of aerosols emitted, if they would stay in the
stratosphere for a longer time period, would result in a 3 degrees
global cooling. Could you point me to the study you are referring to
that calculates this amount of cooling if injecting volcanic aerosols of
the amount of Mt Pinatubo?
Cheers, Simone
>> <mailto:kcal...@carnegiescience.edu>
>> http://dge.stanford.edu/labs/caldeiralab @kencaldeira
>>
>> *Currently visiting * Institute for Advanced Sustainability Studies
>> (IASS) <http://www.iass-potsdam.de/>
>> *and *Potsdam Institute for Climate Impact Research (PIK)
>> <http://www.pik-potsdam.de/>*in Potsdam, Germany.*
> Scotland, with registration number SC005336.
>
>
>
in the article you stated that Mt Pinatubo is assumed to result in a
global cooling of about 0.5 degree. It is also stated in the text of the
article that the amount of aerosols emitted, if they would stay in the
stratosphere for a longer time period, would result in a 3 degrees
global cooling. Could you point me to the study you are referring to
that calculates this amount of cooling if injecting volcanic aerosols of
the amount of Mt Pinatubo?
Cheers, Simone
>> http://dge.stanford.edu/labs/caldeiralab @kencaldeira
>>
>> *Currently visiting * Institute for Advanced Sustainability Studies
>> (IASS) <http://www.iass-potsdam.de/>
>> *and *Potsdam Institute for Climate Impact Research (PIK)
>> <http://www.pik-potsdam.de/>*in Potsdam, Germany.*
>>
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>
> The University of Edinburgh is a charitable body, registered in
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> Scotland, with registration number SC005336.
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Ken Caldeira
Jun 28, 2012, 4:58:31 PM6/28/12
to til...@ucar.edu, geoengi...@googlegroups.com
Simone,
Not reading German, I don't know precisely what is in the story.
What I said to the reporter is that if the aerosol layer similar to that of Mt Pinatubo were sustained, it would produce a cooling of about 3 K.
This is based on estimates of Mt Pinatubo producing around 4 W / m2 of radiative forcing (cf. Crutzen, 2006?), which is similar to a CO2 doubling -- and 3 C per CO2 doubling is in the middle of the range of estimates for climate sensitivity. So, this is just a back-of-envelope calculation.
A question of course, given particle aggregation and so on, is whether such a layer could be sustained.
Best,
Ken
<mailto:kcaldeira@carnegiescience.edu>
http://dge.stanford.edu/labs/caldeiralab @kencaldeira
*Currently visiting * Institute for Advanced Sustainability Studies
(IASS) <http://www.iass-potsdam.de/>
*and *Potsdam Institute for Climate Impact Research (PIK)
<http://www.pik-potsdam.de/>*in Potsdam, Germany.*
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Simone Tilmes
Jun 29, 2012, 11:30:55 AM6/29/12
to Ken Caldeira, geoengi...@googlegroups.com
Dear Ken,
thanks a lot to Matthias, to translate the article!
I think it is important to point out that there is very likely a limit
on how much the Earth's surface could be cooled using sulfate aerosols,
due to coagulation processes and fall out of aerosols. Only less than 2
W/m2 reduction of global net surface SW flux was achieved in the study
by Heckendorn et al., 2009, using a micro-physical model to consider
size distributions of the aerosols. Niemeier et al., 2010, achieved a
stronger forcing if injecting particles at 30hPa, which allow them to
stay longer in the stratosphere. Though it will be hard to inject
particles that high.
Cheers, Simone
References:
Niemeier, U., H. Schmidt and C. Timmreck, The dependency of
geoengineered sulfate aerosol on the emission strategy, Atmos. Sci.
Let., DOI: 10.1002/asl.304, 2010.
Heckendorn P, Weisenstein D, Fueglistaler S, Luo BP, Rozanov E, Schraner
M, Thomason LW, Peter T. 2009. The impact of geoengineering aerosols on
stratospheric temperature and ozone.
Environmental Research Letters 4: 045108. DOI: 10.1088/1748-9326/4/4/045108.
> Tel +44 131 650 5704 <tel:%2B44%20131%20650%205704>
> Mobile 07795 203 195
> www.see.ed.ac.uk/~shs <http://www.see.ed.ac.uk/~shs>
> kcal...@carnegiescience.edu
> <mailto:kcal...@carnegiescience.edu>
> <mailto:kcaldeira@__carnegiescience.edu
> <mailto:kcal...@carnegiescience.edu>>
> http://dge.stanford.edu/labs/__caldeiralab
> <mailto:geoengi...@googlegroups.com>.
> <mailto:geoengineering%2Bunsu...@googlegroups.com>.
> <http://groups.google.com/group/geoengineering?hl=en>.
> <mailto:geoengi...@googlegroups.com>.
> <mailto:geoengineering%2Bunsu...@googlegroups.com>.
> <http://groups.google.com/group/geoengineering?hl=en>.
>
>
thanks a lot to Matthias, to translate the article!
I think it is important to point out that there is very likely a limit
on how much the Earth's surface could be cooled using sulfate aerosols,
due to coagulation processes and fall out of aerosols. Only less than 2
W/m2 reduction of global net surface SW flux was achieved in the study
by Heckendorn et al., 2009, using a micro-physical model to consider
size distributions of the aerosols. Niemeier et al., 2010, achieved a
stronger forcing if injecting particles at 30hPa, which allow them to
stay longer in the stratosphere. Though it will be hard to inject
particles that high.
Cheers, Simone
References:
Niemeier, U., H. Schmidt and C. Timmreck, The dependency of
geoengineered sulfate aerosol on the emission strategy, Atmos. Sci.
Let., DOI: 10.1002/asl.304, 2010.
Heckendorn P, Weisenstein D, Fueglistaler S, Luo BP, Rozanov E, Schraner
M, Thomason LW, Peter T. 2009. The impact of geoengineering aerosols on
stratospheric temperature and ozone.
Environmental Research Letters 4: 045108. DOI: 10.1088/1748-9326/4/4/045108.
> Mobile 07795 203 195
> www.see.ed.ac.uk/~shs <http://www.see.ed.ac.uk/~shs>
>
>
> On 28/06/2012 06:27, Ken Caldeira wrote:
>
> pdf attached.
>
> http://www.nzz.ch/wissen/__wissenschaft/sonnenschutz-__fuer-die-erde-1.17282213
>
> On 28/06/2012 06:27, Ken Caldeira wrote:
>
> pdf attached.
>
> <http://www.nzz.ch/wissen/wissenschaft/sonnenschutz-fuer-die-erde-1.17282213>
>
>
> _______________
> Ken Caldeira
>
> Carnegie Institution for Science
>
> Dept of Global Ecology
> 260 Panama Street, Stanford, CA 94305 USA
> +1 650 704 7212 <tel:%2B1%20650%20704%207212>
>
>
> _______________
> Ken Caldeira
>
> Carnegie Institution for Science
>
> Dept of Global Ecology
> 260 Panama Street, Stanford, CA 94305 USA
> kcal...@carnegiescience.edu
> <mailto:kcal...@carnegiescience.edu>
> <mailto:kcaldeira@__carnegiescience.edu
> <mailto:kcal...@carnegiescience.edu>>
> http://dge.stanford.edu/labs/__caldeiralab
> <http://dge.stanford.edu/labs/caldeiralab> @kencaldeira
>
> *Currently visiting * Institute for Advanced Sustainability
> Studies
> (IASS) <http://www.iass-potsdam.de/>
> *and *Potsdam Institute for Climate Impact Research (PIK)
> <http://www.pik-potsdam.de/>*__in Potsdam, Germany.*
>
> *Currently visiting * Institute for Advanced Sustainability
> Studies
> (IASS) <http://www.iass-potsdam.de/>
> *and *Potsdam Institute for Climate Impact Research (PIK)
>
>
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Andrew Lockley
Jun 29, 2012, 12:00:03 PM6/29/12
to til...@ucar.edu, geoengineering
30 hPa is about 25kms. That's pretty normal for release studies. See for example Aurora flight services report
I'm doing a paper at present which shows you can loft a shell that high for very little money - probably an order of magnitude cheaper than Aurora calculated. I've not finished the calcs yet.
You could hit those costs using an extended Mark 7 Iowa class 16 in gun. Methane/air propellant should get you to 25k, but using a H2 / O2 propellant (run rich) can get far higher by improving speed of sound. To cut shell mass you can use an enlarged, fin-stabilized aluminum or titanium shell. Projectiles would splashdown, to be reused or scrapped.
A
<mailto:kcaldeira@carnegiescience.edu>
<mailto:kcaldeira@__carnegiescience.edu
<mailto:kcaldeira@carnegiescience.edu>>
http://dge.stanford.edu/labs/__caldeiralab
<http://dge.stanford.edu/labs/caldeiralab> @kencaldeira
*Currently visiting * Institute for Advanced Sustainability
Studies
(IASS) <http://www.iass-potsdam.de/>
*and *Potsdam Institute for Climate Impact Research (PIK)
<http://www.pik-potsdam.de/>*__in Potsdam, Germany.*
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Andrew Lockley
Jul 3, 2012, 7:23:44 PM7/3/12
to geoengineering
To comment further on the upper bound for aerosol forcing: the
following abstract may be of interest. Consideration of such aerosol
indirect effects, coupled with the potential methane feedbacks,
suggests a range for future warming scenarios much wider than IPCC
ranges. As such, clarity on the upper bounds of radiative forcing
available under geoengineering programmes would be very helpful. In
my personal opinion, it's crucial to establish whether or not a single
geoengineering programme, or a combination, would be capable of
controlling global mean temperatures under conditions of both
high-feedback and high global warming potential for methane. I fear
that they may not.
Reference/abstract below
A
Atmos. Chem. Phys., 11, 6961-6969, 2011
www.atmos-chem-phys.net/11/6961/2011/
doi:10.5194/acp-11-6961-2011
Large methane releases lead to strong aerosol forcing and reduced cloudiness
T. Kurtén1,2, L. Zhou1, R. Makkonen1, J. Merikanto1, P. Räisänen3, M.
Boy1, N. Richards4, A. Rap4, S. Smolander1, A. Sogachev5, A.
Guenther6,
Abstract. The release of vast quantities of methane into the
atmosphere as a result of clathrate destabilization is a potential
mechanism for rapid amplification of global warming. Previous studies
have calculated the enhanced warming based mainly on the radiative
effect of the methane itself, with smaller contributions from the
associated carbon dioxide or ozone increases. Here, we study the
effect of strongly elevated methane (CH4) levels on oxidant and
aerosol particle concentrations using a combination of
chemistry-transport and general circulation models. A 10-fold increase
in methane concentrations is predicted to significantly decrease
hydroxyl radical (OH) concentrations, while moderately increasing
ozone (O3). These changes lead to a 70 % increase in the atmospheric
lifetime of methane, and an 18 % decrease in global mean cloud droplet
number concentrations (CDNC). The CDNC change causes a radiative
forcing that is comparable in magnitude to the longwave radiative
forcing ("enhanced greenhouse effect") of the added methane. Together,
the indirect CH4-O3 and CH4-OH-aerosol forcings could more than double
the warming effect of large methane increases. Our findings may help
explain the anomalously large temperature changes associated with
historic methane releases.
> To post to this group, send email to geoengi...@googlegroups.com.
following abstract may be of interest. Consideration of such aerosol
indirect effects, coupled with the potential methane feedbacks,
suggests a range for future warming scenarios much wider than IPCC
ranges. As such, clarity on the upper bounds of radiative forcing
available under geoengineering programmes would be very helpful. In
my personal opinion, it's crucial to establish whether or not a single
geoengineering programme, or a combination, would be capable of
controlling global mean temperatures under conditions of both
high-feedback and high global warming potential for methane. I fear
that they may not.
Reference/abstract below
A
Atmos. Chem. Phys., 11, 6961-6969, 2011
www.atmos-chem-phys.net/11/6961/2011/
doi:10.5194/acp-11-6961-2011
Large methane releases lead to strong aerosol forcing and reduced cloudiness
T. Kurtén1,2, L. Zhou1, R. Makkonen1, J. Merikanto1, P. Räisänen3, M.
Boy1, N. Richards4, A. Rap4, S. Smolander1, A. Sogachev5, A.
Guenther6,
Abstract. The release of vast quantities of methane into the
atmosphere as a result of clathrate destabilization is a potential
mechanism for rapid amplification of global warming. Previous studies
have calculated the enhanced warming based mainly on the radiative
effect of the methane itself, with smaller contributions from the
associated carbon dioxide or ozone increases. Here, we study the
effect of strongly elevated methane (CH4) levels on oxidant and
aerosol particle concentrations using a combination of
chemistry-transport and general circulation models. A 10-fold increase
in methane concentrations is predicted to significantly decrease
hydroxyl radical (OH) concentrations, while moderately increasing
ozone (O3). These changes lead to a 70 % increase in the atmospheric
lifetime of methane, and an 18 % decrease in global mean cloud droplet
number concentrations (CDNC). The CDNC change causes a radiative
forcing that is comparable in magnitude to the longwave radiative
forcing ("enhanced greenhouse effect") of the added methane. Together,
the indirect CH4-O3 and CH4-OH-aerosol forcings could more than double
the warming effect of large methane increases. Our findings may help
explain the anomalously large temperature changes associated with
historic methane releases.
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Russell Seitz
Aug 22, 2012, 8:12:06 PM8/22/12
to geoengi...@googlegroups.com, kcal...@carnegiescience.edu
Translated into German ?
I expect it sounds better in Schwyzerdutsch
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