[Vision2020] Barton Paul Levenson's Response in Lindzen and Choi (2009) Discussion

Sun Jan 10 17:41:50 PST 2010

In think Barton Paul Levenson's post in the following discussion regarding
the first published response to Lindzen and Choi (2009) contains some
excellent answers, backed by scientific research, to some of the common
skeptical arguments regarding anthropogenic climate change.  I pasted in his
response, number 31, after the introduction comments below (or read here:
http://www.realclimate.org/index.php/archives/2007/08/the-co2-problem-in-6-easy-steps/
 ).

http://www.realclimate.org/index.php/archives/2010/01/first-published-response-to-lindzen-and-choi/#comment-153884
 First published response to Lindzen and Choi
Filed under:

   - Climate Science<http://www.realclimate.org/index.php/archives/category/climate-science/>
   - Climate modelling<http://www.realclimate.org/index.php/archives/category/climate-science/climate-modelling/>

— gavin @ 8 January 2010

The first published response to Lindzen and Choi
(2009)<http://www.agu.org/journals/gl/gl0916/2009GL039628/>(LC09) has
just appeared “in
press <http://www.agu.org/journals/pip/gl/2009GL042314-pip.pdf>”
(subscription) at GRL. LC09 purported to determine climate sensitivity by
examining the response of radiative fluxes at the Top-of-the-Atmosphere
(TOA) to ocean temperature changes in the tropics. Their conclusion was that
sensitivity was very small, in obvious contradiction to the models.

In their commentary, Trenberth, Fasullo, O’Dell and Wong examine some of the
assumptions that were used in LC09’s analysis. In their guest
commentary<http://www.realclimate.org/index.php/archives/2010/01/lindzen-and-choi-unraveled>,
they go over some of the technical details, and conclude, somewhat
forcefully, that the LC09 results were not robust and do not provide any
insight into the magnitudes of climate feedbacks.

Coincidentally, there is a related paper (Chung, Yeomans and Soden) also in
press<http://www.agu.org.ezproxy.cul.columbia.edu/journals/pip/gl/2009GL041889-pip.pdf>(sub.
req.) at GRL which also compares the feedbacks in the models to the
satellite radiative flux measurements and also comes to the conclusion that
the models aren’t doing that badly. They conclude that

In spite of well-known biases of tropospheric temperature and humidity in
climate models, comparisons indicate that the intermodel range in the rate
of clear-sky radiative damping are small despite large intermodel
variability in the mean clear-sky OLR. Moreover, the model-simulated rates
of radiative damping are consistent with those obtained from satellite
observations and are indicative of a strong positive correlation between
temperature and water vapor variations over a broad range of spatiotemporal
scales.

It will take a little time to assess the issues that have been raised (and
these papers are unlikely to be the last word), but it is worth making a
couple of points about the process. First off, LC09 was not a nonsense paper
– that is, it didn’t have completely obvious flaws that should have been
caught by peer review (unlike say, McLean et al, 2009 or Douglass et al,
2008). Even if it now turns out that the analysis was not robust, it was not
that the analysis was not worth trying, and the work being done to
re-examine these questions is a useful contributions to the literature –
even if the conclusion is that this approach to the analysis is flawed.

More generally, this episode underlines the danger in reading too much into
single papers. For papers that appear to go against the mainstream (in
either direction), the likelihood is that the conclusions will not stand up
for long, but sometimes it takes a while for this to be clear. Research at
the cutting edge – where you are pushing the limits of the data or the
theory – is like that. If the answers were obvious, we wouldn’t need to do
research.

*Update:* More commentary at
DotEarth<http://dotearth.blogs.nytimes.com/2010/01/08/a-rebuttal-to-a-cool-climate-paper/>including
a response from Lindzen.
 Comments (pop-up) (101) <http://www.realclimate.org/?comments_popup=2671>
-----------------------------------------
 31
 Barton Paul Levenson <http://bartonpaullevenson.com/> says:
9 January 2010 at 7:01
AM<http://www.realclimate.org/index.php/archives/2010/01/first-published-response-to-lindzen-and-choi/comment-page-1/#comment-153810>

Josh: 1. Demonstrate causation, not just correlation of CO2 levels relative
to global temperature.

BPL:

Fourier, J.-B. J. 1824. “Memoire sur les Temperatures du Globe Terrestre et
des Espaces Planetaires.” Annales de Chemie et de Physique 2d Ser. 27,
136-167.

Tyndall, J. 1859. “Note on the Transmission of Radiant Heat through Gaseous
Bodies.” Proceed. Roy. Soc. London 10, 37-39.

Arrhenius, S.A. 1896. “On the Influence of Carbonic Acid in the Air upon the
Temperature of the Ground.” Phil. Mag. 41, 237-275.

Royer, D.L. 2006. “CO2-forced climate thresholds during the Phanerozoic”
Geochim. Cosmochim. Acta 70, 5665-5675.

Came R.E., J.M. Eiler, J. Veizer, K. Azmy, U. Brand, and C.R. Weidman 2007.
“Coupling of surface temperatures and atmospheric CO2 concentrations during
the Palaeozoic era.” Nature 449, 198-201.

Doney, S.C. et al. 2007. “Carbon and climate system coupling on timescales
from the Precambrian to the Anthropocene” Ann. Rev. Environ. Resources 32,
31-66.

Horton, D.E. et al. 2007. “Orbital and CO2 forcing of late Paleozoic
continental ice sheets” Geophys. Res. Lett. L19708.

Fletcher, B.J. et al. 2008. “Atmospheric carbon dioxide linked with Mesozoic
and early Cenozoic climate change” Nature Geoscience 1, 43-48.

W. M. Kurschner et al. 2008. “The impact of Miocene atmospheric carbon
dioxide fluctuations on climate and the evolution of the terrestrial
ecosystem”Proc. Natl. Acad. Sci. USA 105, 499-453.

Lean, J.L. and D.H. Rind 2008. “How natural and anthropogenic influences
alter global and regional surface temperatures: 1889 to 2006.” Geophys. Res.
Lett. 35, L18701.

Royer, D.L. 2008. “Linkages between CO2, climate, and evolution in deep
time” Proc. Natl Acad. Sci. USA 105, 407-408.

Zachos, J.C. 2008. “An early Cenozoic perspective on greenhouse warming and
carbon-cycle dynamics” Nature 451, 279-283.

2. Use real-world emperical evidence, not flawed computer models.

See above. For carbon dioxide rising, see

Keeling, C.D. 1958. “The Concentration and Isotopic Abundances of
Atmospheric Carbon Dioxide in Rural Areas.” Geochimica et Cosmochimica Acta,
13, 322-334.

Keeling, C.D. 1960. “The Concentration and Isotopic Abundances of Carbon
Dioxide in the Atmosphere.” Tellus 12, 200-203.

For the new carbon dioxide being anthropogenic in origin, see

Suess, H.E. 1955. “Radiocarbon Concentration in Modern Wood.” Sci. 122,
415-417.

Revelle, R. and H.E. Suess 1957. “Carbon Dioxide Exchange between Atmosphere
and Ocean and the Question of an Increase of Atmospheric CO2 During the Past
Decades.” Tellus 9, 18-27.

3. Show emperical evidence for temperature rises following CO2 level
increases, not before.

Google “PETM,” or check here, where a tight correlation is shown between
temperature anomalies and CO2 level in the same year:

http://BartonPaulLevenson.com/Correlation.html<http://bartonpaullevenson.com/Correlation.html>

In a natural deglaciation, temperature rise does indeed precede carbon
dioxide increase, because warmer water holds less CO2 and it bubbles out of
the ocean. The additional CO2 then raises the temperature further in a
feedback. But that is NOT what is happening now. We know the new CO2 is
coming from fossil fuels and deforestation, not the ocean, through its
radioisotope signature.

4. Demonstrate that CO2 is the sole major forcing in global temperature
changes, not a minor player in a much larger game, involving clouds, solar
flux and CRF.

This is a straw-man argument. Nobody competent ever said CO2 was “the sole
major forcing in global temperature changes.” It happens to be the major
(not the only) cause of the present global warming, but at other epochs
other causes have been more important. See the Lean paper referenced above
for an example of how they sort out change attribution.

5. Show that CO2 levels and greenhouse effect is not already saturated.

At the lowest levels of the atmosphere, it is mostly saturated–and it
doesn’t matter. The atmosphere as a whole is *never* entirely saturated, and
can’t be, and every level contributes to the surface temperature. Please
read:

http://BartonPaulLevenson.com/Saturation.html<http://bartonpaullevenson.com/Saturation.html>

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Vision2020 Post: Ted Moffett
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