The start was Andrew’s email, which was based on a presentation given at CEC17
(sorry, there weren’t any viewgraphs, but you’ve already got the summary).
There’s nothing inherently “wrong” with any approach. Eventually we’ll need a
more serious engineering analysis of different options
Hi Andrew,
I personally don’t see this as a problem (and I’ve worked a bit with Wake on
question). The direct costs of getting stuff to the stratosphere are not going
to be the long-term barrier to deployment (and might not even be the biggest
costs of deployment, assuming one needs to
GTC, equivalent to 12-26%
of twenty-first-century emissions at a cost of under US$0.5 per tCO2.
Douglas MacMartin
Senior Research Associate & Senior Lecturer, Mechanical and Aerospace
Engineering
Faculty Fellow, Cornell Atkinson Center for a Sustainable Future
Cornell University
(650)
I think it would be more accurate to say that, based on what we know today, we
don’t know what the costs of DAC would be if deployed at scale. I understand
that people have made estimates, but it is very hard to reliably forecast costs
from things done at 3 or more (?) orders of magnitude
Hi Ken,
We tried to write some down in our Earth’s Future piece last year, at least for
stratospheric aerosols
MacMartin, D. G., B. Kravitz, J.C.S. Long, and P.J. Rasch, “Geoengineering with
stratospheric aerosols: what do we not know after a decade of research?”
Earth’s Future, 4,
I haven’t read the article, but just in case there’s anyone who hasn’t been
following this, the abstract by itself is extremely misleading.
It would be pretty stupid and irresponsible to issue carbon credits for an
approach for which there is no evidence for the claimed amount of net
Embark on what?
The Guardian article is somewhat confused in general. Basically, there’s only
two real observations. Harvard has some research money. And some quite small
fraction of that research money will go into very small scale outdoor field
experiments.
I personally think it
Actually I think it quite plausible that fossil fuels will be competitive in
2040+ (absent carbon pricing). I don’t see anything on the horizon in storage
that would make me believe that that problem is guaranteed to be solved by then
(I think it’s really hard to predict when there’s orders of
Agree that it isn’t a blanket endorsement, but I’m not sure what disagreement
there is; the only geoengineering research that doesn’t help understand
biodiversity impacts would be research into the hardware needed for deployment.
Everything else that I can think of would ultimately be needed
I think if you can get them there, keeping them there is comparatively easy...
(The advantage of it being an equilibrium point is that the effort required to
keep it there is in principle small.)
Though I think it would be cheaper to massively transform the world's energy
system in the next
Stephen – when I was in industry I worked on the engineering of a project that
hadn’t yet worked out the objectives, and I don’t think we should be repeating
that type of mistake (yes, the project was a disaster… we designed the
hardware, then we figured out what hardware we needed, and after 6
, Mayfield Road, Edinburgh EH9 3DW, Scotland s.sal...@ed.ac.uk
<mailto:s.sal...@ed.ac.uk> , Tel +44 (0)131 650 5704, Cell 07795 203 195,
WWW.homepages.ed.ac.uk/shs <http://WWW.homepages.ed.ac.uk/shs> , YouTube Jamie
Taylor Power for Change
On 21/11/2016 14:23, Douglas MacMartin wrot
ring@googlegroups.com [mailto:geoengineering@googlegroups.com]
On Behalf Of Myles Allen
Sent: Sunday, November 20, 2016 1:47 PM
To: Douglas MacMartin <macma...@cds.caltech.edu>; 'Stephen Salter'
<s.sal...@ed.ac.uk>; geoengineering@googlegroups.com; Oxford Martin Info
<i...@oxfordmartin.ox.ac.uk
The short answer on what altitude we “need” is, nobody knows yet. The climate
science hasn’t been funded enough to answer that type of question. So any
number anyone has written down is speculation or educated guess until one can
more seriously evaluate the pros and cons. That makes it
I’m sorry, but I fail to see the connection between improvements in information
technology (e.g. self-driving cars), which are solvable by virtue of faster
computation and better algorithms, and CDR, which is limited by energetics and
real physical and chemical processes while dealing with a
Hi Stephen,
You’re right, in the final version we should word that better. Thanks!
I think that doing this for solar reduction (clearly a first but not a last
step) suggests that the tropospheric climate response to an imposed radiative
forcing is, in climate models, pretty linear for
And yet another area where turning down the sun won’t have the same effect as
stratospheric aerosols. (Since it has the opposite sign in the stratosphere.)
From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com]
On Behalf Of Charles H. Greene
Sent: Wednesday, May 11,
As an engineer I agree that engineering is purposeful. The other three words I
disagree with, as would any other engineer. (Wikipedia's definition of
engineering is reasonable)
Precision is clearly a subjective construct, as is predictability. I am quite
confident for example that adding strat
“The crux is that Morton does not believe pathways without geoengineering can
avoid climate harms without causing other serious social or economic harms.”
Isn’t that patently obvious at this point? That of course is not an argument
for deploying solar geoengineering, simply an argument in
Cooling the tropics more than the poles is also a choice for stratospheric
aerosol injection; if you want that effect you can presumably do that, and if
you’d rather cool the poles more than the tropics you could do that instead.
From: geoengineering@googlegroups.com
in the stratosphere. It is the one to
two-year life that stops you having local control. Even if you could choose
the starting point(s) how would you then direct it?
Stephen
On 07/09/2015 17:57, Douglas MacMartin wrote:
Cooling the tropics more than the poles is also a choice for stratospheric
Didn’t read quite as carefully as I could, but two quick comments:
i) the assumption in extending the argument to research is that
more research increases the likelihood of SRM being used as an excuse not to
mitigate; I suspect that is unfounded. That is, more research may make
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