[Vision2020] Exploring Implications of Levenson's List of Estimates of Climate Sensitivity

Ted Moffett starbliss at gmail.com
Mon Jul 19 11:16:24 PDT 2010

 Regarding the list of peer reviewed published scientific estimates of
climate sensitivity from Levenson's research
( *http://bartonpaullevenson.com/ClimateSensitivity.html*<http://bartonpaullevenson.com/ClimateSensitivity.html>
referenced in your comments below,  there are implications worth exploring
concerning your arguments to question anthropogenic climate warming.

I thought it might be useful to pedantically point out that Kelvin and
Celsius indicate the same temperature change per degree.  But Kelvin starts
at absolute zero, minus 273 Celsius (thus there are no minus Kelvin
readings), while Celsius starts at the freezing point of H2O, with minus
readings below, positive above.  100 Celsius is the boiling point of H2O.
Climate sensitivity estimates in Kelvin indicate the same result as if they
were given in Celsius:


*Paul Rumelhart* godshatter at yahoo.com
*Mon Jun 21 19:06:15 PDT 2010*

"The link you posted on climate sensitivity shows values that are all over
board, from 0.26 to 5.5 Kelvins.  There doesn't seem to be a trend that
shows them converging on a final number, either.  Since 2000, the range
is 0.75 to 4.5 Kelvin.  Anything under about 1.2 is probably not a
problem, since it implies strong negative feedback. Anything under about 1.2
is probably not a problem, since it implies strong negative feedback.
Anything over about 2 could be a definite problem, depending upon the exact
involved.  It doesn't appear to me that climate scientists are on top of
the feedback problem, either.  I'm not even confident that they have
identified them all, let alone figured out exactly how they affect each


These estimates on climate sensitivity from Barton Paul Levenson are not
"all over the board," as you wrote.  Not one indicates a reduction in
temperature from a doubling of atmospheric CO2.  If they were "all over the
board" some would show negative feedback(s) that more than overcome the
radiative forcing of CO2, resulting in predictions of a temperature
reduction, especially if your arguments referencing "Chaos Theory" applied
to global climate are compelling.

Furthermore, you make no reference to Levenson's analysis revealing the mean
of these studies indicates climate sensitivity to be 2.86 or 3.15
Kelvin.   This mean result can be argued indicates that based on these
studies, there is a significant probability that climate sensitivity is high
enough to justify taking action to reduce CO2 emissions.

Given your emphasis on "Chaos Theory" to question the scientific consensus
that human impacts are the primary driver of the the rapid and profound
global climate change currently being observed which will increase
significantly, it is a challenge to your argument that all these studies on
climate sensitivity show a temperature increase.  If the global climate
system was as "chaotic" as you suggest, there would be a significant number
of peer reviewed published results predicting doubling atmospheric CO2 would
decrease global average temperature from strong negative feedbacks,
perhaps from cloud formation feedbacks, a variable you have pointed out that
climate scientists have difficulty modeling.  That all these estimates of
climate sensitivity from Levenson's research show an increase in
temperature, suggests that on this scientific question the climate system is
not as "chaotic" as you imply.  Indeed, the scientific question of climate
sensitivity is perhaps one of the best examples of a question focusing on
global *climate*, rather than more chaotic local or regional *weather*.

Perhaps you can offer a list of peer reviewed published estimates of climate
sensitivity predicting temperature decreases in global average temperature
from doubling atmospheric CO2?  Even the "dean" of anthropogenic climate
change skeptics (to quote NASA climate scientist James Hansen from his book
"Storms of My Grandchildren" http://www.stormsofmygrandchildren.com/ ),
MIT's Richard Lindzen, finds climate sensitivity to be positive, though
minimal.  He has argued with his "Iris" theory that the climate system has
mechanisms to dissipate thermal energy to space that lower temperature.
However, Lindzen's "Iris" theory has not held up to scientific peer review
( [Vision2020] Anthropogenic Warming Skeptic Richard Lindzen Deconstructed
Via Peer Review:
http://mailman.fsr.com/pipermail/vision2020/2009-July/064927.html  ,
[Vision2020] MIT Meteorologist Lindzen's Recent Climate Science Paper Poorly
Peer Reviewed, With Direct Critical Comments Rejected by GRL?* *
http://mailman.fsr.com/pipermail/vision2020/2010-January/068047.html ).

As far as these studies converging on a "final number" (Levenson's analysis
does suggest "convergence" in the graphs he presents.  Quoting Levenson, "In
summary statistics, N = 61, the mean is 2.86, and the sample standard
deviation is 1.50. Notice how the estimates are beginning to converge with
time"), climate science operates within a probable range of future
temperature increases in global average temperatures from human CO2
emissions and other impacts.  If you are demanding a "final number" before
declaring the science confidently predicts a high probability of a
significant temperature increase from doubling atmospheric CO2, you are
making a scientifically flawed argument.

Also, there are ten estimates of climate sensitivity in Levenson's list from
2000-2006.  As you wrote, "the range is 0.75 to 4.5 Kelvin."  But nine of
the estimates are from 1.8 to 4.5 Kelvin.  Only one estimate, 0.75
Kelvin, shows climate sensitivity to be low enough to indicate
human emissions increasing atmospheric CO2 and temperature are not a major
problem, as shown below (however, ocean acidification is another important
issue indicating CO2 emissions should be reduced, regardless of the
magnitude of global warming).  It is not unreasonable to question one low
estimate when nine others are much higher:


  Boer et al. 2000 3.5 Washington et al. 2000 2.1 Dai et al. 2001 2.1 Wetherald
et al. 2001 4.5 Boer and Yu 2003 3.50 Shaviv and Veizer 2003 0.75 Stern 2005
4.4 Sumi 2005 2.8 Goosse et al. 2006 1.8 Hegerl et al. 2006 2.5

I'll briefing consider evidence that climate sensitivity is not a low  0.75

So far, human CO2 emissions have increased atmospheric CO2 by approximately
110 ppm, from a pre-industrial level of about 280 ppm to a current level of
about 390 ppm ( http://co2now.org/ ), less than half of a doubling of
atmospheric CO2.  Yet global average temperatures since 1880, according to
climate scientists at the Goddard Institute for Space Studies (
http://data.giss.nasa.gov/gistemp/graphs/ ), have already increased 0.8
Celsius, depending on the error bars interpretation.

Of course anthropogenic climate change skeptics, even if they accept this
temperature increase as based on reliable temperature data, which many do
not, will claim the increase is mostly from natural climate change
variables. Read Roy Spencer on this question, a well known often quoted
skeptic whose climate science analysis indicates natural variables are
warming climate, that overall does not survive scientific peer review:

However, the consensus after decades of analysis by climate scientists
around the globe is that natural climate change does not explain the 0.8
degree Celsius increase since 1880.  Read 2010 reports from the National
Academy of Sciences on climate change:
http://www8.nationalacademies.org/onpinews/newsitem.aspx?RecordID=05192010 and
2010 release from the American Statistical Association:
http://magazine.amstat.org/blog/2010/03/01/climatemar10/ .

Professor Scott Mandia's analysis on this issue is instructive, especially
the implications of tropospheric warming coupled with stratospheric cooling,
as evidence temperature increases are not due to certain natural variables.
Mandia's analysis indicates Roy Spencer's claims at the website already
given cannot be correct.  The isotope signature ratio of the CO2 in the
atmosphere indicates the CO2 increase since pre-industrial level must be due
to the burning of fossil fuels and land use impacts, and the tropospheric
warming coupled with stratospheric cooling is not explained by solar, cloud,
or ocean current climate variables.  Quoting Mandias: "Solar forcing, cloud
cover, ENSO, PDO, NAO, etc. cannot explain a cooler stratosphere even when
ozone depletion is accounted for. Increasing greenhouse gases explain this
coupling very well and climate models predict a warmer troposphere and a
cooler stratosphere with increased greenhouse gases."  Read on this issue

The physics regarding CO2's radiative forcing in Earth's atmosphere can
largely explain Earth's warming trend, as human emissions have increased
atmospheric CO2 level, according to the American Institute of Physics.  The
following website explores the history of the science as far back as the
1800s, with intense debate among scientists, among them Sherwood Idso, one
of the scientists listed in Levenson's estimates of climate sensitivity who
found a low value for climate sensitivity:
http://www.aip.org/history/climate/Radmath.htm .

If there were also profound natural variables warming Earth's climate at
this point in time, it's likely even more temperature increase would
be observed.  In fact, there are natural climate trends that could be
cooling the Earth's climate at this point.  Read March 2005 article by
Ruddiman in Scientific American regarding an argument Earth should be
tending to cool by natural variables:

An increase in atmospheric CO2 from 280 to 390 ppm, less than half of a
doubling of CO2 level, is already resulting in a global temperature increase
(0.8 Kelvin, or Celsius) that indicates climate sensitivity is well above
0.75 Kelvin.  It would be a very dangerous gamble for humanity to push
atmospheric CO2 level to a doubling of CO2 from pre-industrial level to 560
ppm, given the probability climate sensitivity is significant.

The climate feedbacks that are claimed are not well understood enough to
make credible predictions regarding future climate, have been studied by
climate scientists for decades; and reliable predictions are quantified
within a range of probabilities. Read 2009 MIT study on probabilities of
temperature increases:
http://globalchange.mit.edu/files/document/MITJPSPGC_Rpt169.pdf .
Vision2020 Post: Ted Moffett
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.fsr.com/pipermail/vision2020/attachments/20100719/38bb35df/attachment-0001.html 

More information about the Vision2020 mailing list