Dear Ken,
I think you are being rather picky with words. In any case, I never
said it cannot be tested. I said it cannot be fully tested in a
real-world in situ experiment without full-scale implementation, because
the climate signal will be drowned out by chaotic climate variations and
because injecting into a pristine stratosphere cannot test injecting
into an existing cloud. Of course computers can be used for testing.
That is what I do, and I advocate much more of it. The statement below
refers to in situ experimentation.
Alan
Alan Robock, Professor II (Distinguished Professor)
Editor, Reviews of Geophysics
Director, Meteorology Undergraduate Program
Department of Environmental Sciences Phone: +1-732-932-9800 x6222
Rutgers University Fax: +1-732-932-8644
14 College Farm Road E-mail: [email protected]
New Brunswick, NJ 08901-8551 USA http://envsci.rutgers.edu/~robock
On 9/27/2010 12:00 PM, Ken Caldeira wrote:
Folks,
Robock et al and Fleming have both asserted that "geoengineering
cannot be tested".
Robock et al (Science, 2010): /"We argue that geoengineering cannot be
tested without full-scale implementation."/
Fleming (Slate): "/Global climate engineering is untested and
untestable.../"
These statements seem either trivially true or patently false,
depending on interpretation.
*Trivially true:* /If the only thing that you are willing to consider
a test is the thing itself, then trivially there is no test other than
the thing itself./
*Patently false:* /There are many tests that can be done that can help
us understand possible consequences of a geoengineering deployment./
One could imagine someone saying in the United States in the 1950's,
"There is no way you can test the proposed interstate highway system,
because you will not understand all its effects until it has been
deployed." This is true, in the sense that you could not predict in
advance detailed effects that the interstate highway system would have
on the spread of suburbia, traffic jams, the rise of the SUV, and so on.
But, in the 1950's they could have tested the concrete, built a small
stretch of road and learned about its construction and use etc. Would
we say "/The interstate highway system cannot be tested without
full-scale implementation?/" Would we say "T/he interstate highway
system is untested and untestable?/" I think we would say, "There are
plenty of tests we can do, but of course we will not understand the
full consequences of our implementation until the implementation is
complete."
We perform tests to improve our understanding. We never have full
understanding of consequences of our actions before we act. We
hopefully act in ways that will have the greatest rational expectation
of positive outcomes. We do research to avoid having rational
expectations that do not accord with facts on the ground.
Many people have regarded Mt Pinatubo as performing a natural
experiment of geoengineering -- a test of the idea of solar radiation
management. Like all tests, Mt Pinatubo was not a perfect test (e.g.,
the aersols were not maintained in the stratosphere, etc).
Nevertheless, Mt Pinatubo has functioned as a natural test of some of
the concepts underlying solar radiation management.
In 2003, Alan Robock wrote a paper called "Introduction: Mt. Pinatubo
as a test of climate feedback mechanisms".
(http://climate.envsci.rutgers.edu/pdf/VEAChapter1_Robocknew.pdf).
How is it logically possible that Mt Pinatubo could function as a test
of climate feedback mechanisms, but not of geoengineering (ie SRM),
when those climate feedback mechanisms are central to the climate
system response to any geoengineering effort?
Furthermore, hasn't Alan claimed to have tested geoengineering
concepts in his climate models and found them wanting? How can you
have it both ways: testing geoengineering concepts and claiming the
concepts are untestable?
The list of possible useful geoengineering tests could be a long one,
and includes tests of small scale physics, climate model simulations,
observations of climate variability, ecosystem experiments,
observations of behavior of natural or introduced particles on
stratospheric transport and chemistry, small scale or short-term
deployments, etc. (I am not advocating all of these, just listing them.)
It seems odd, when there are a number of people eager to perform a
wide range of tests on geoengineering concepts, to have a small
minority claiming that these concepts simply can't be tested
(especially when members of that minority have themselves been
involved in testing geoengineering concepts).
So, do the people who say that "geoengineering can't be tested" mean
something that is both true and substantive (i.e., couldn't also have
been said of, for example, the development of the US interstate
highway system)? If so, it would be interesting to hear what this
non-trivial interpretation might be.
Best,
Ken
___________________________________________________
Ken Caldeira
Carnegie Institution Dept of Global Ecology
260 Panama Street, Stanford, CA 94305 USA
+1 650 704 7212 [email protected]
<mailto:[email protected]>
http://dge.stanford.edu/labs/caldeiralab @kencaldeira
--
You received this message because you are subscribed to the Google
Groups "geoengineering" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to
[email protected].
For more options, visit this group at
http://groups.google.com/group/geoengineering?hl=en.
--
You received this message because you are subscribed to the Google Groups
"geoengineering" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to
[email protected].
For more options, visit this group at
http://groups.google.com/group/geoengineering?hl=en.
