There is an article today in Science Express by Stefan Rahmstorf, Anny
Cazenave, John A. Church, James E. Hansen, Ralph F. Keeling, David E.
Parker,Richard C. Somerville entitled “Recent Climate Observations Compared to
Projections” which is remarkably blatant about its cherry picking of papers to
support their view and in ignoring peer reviewed papers that do not.
They make statements such as
“The global mean surface temperature increase (land and ocean combined) in
both the NASA GISS data set and the Hadley Centre / Climatic Research Unit data
set is 0.33 ºC for the 16 years since 1990, which is in the upper part of the
range projected by the IPCC. Given the relatively short 16- year time period
considered, it will be difficult to establish the reasons for this relatively
rapid warming, although there are only a few likely possibilities. The first
candidate reason candidate is climate forcings other than CO2: While the
concentration of other greenhouse gases has risen more slowly than assumed in
the IPCC scenarios, a smaller aerosol cooling than expected is a possible cause
of the extra warming. A third candidate is an underestimation of the climate
sensitivity to CO2 (i.e., model error).”
This set of reasoning has conveniently ignored the conclusions of the
following peer reviewed papers which document a warm bias in existing global
surface land air temperature trend assessments; i.e.
Pielke Sr., R.A., and T. Matsui, 2005: Should light
wind and windy nights have the same temperature trends at individual levels even
if the boundary layer averaged heat content change is the same? Geophys.
Res. Letts., 32,
No. 21, L21813, 10.1029/2005GL024407. [and
as summarized on Climate Science in January 2006]
Hale, R.C., K.P. Gallo, T.W. Owen, and T.R. Loveland, Land
use/land cover change effects ontemperature trends at U.S. Climate Normals
Stations, Geophys. Res. Lett., 33, doi:10.1029/2006GL026358, 2006
which were available to the authors of the Science Express paper. Our new
Pielke Sr., R.A., C. Davey, D. Niyogi, K. Hubbard, X. Lin, M. Cai, Y.-K. Lim,
H. Li, J. Nielsen-Gammon, K. Gallo, R. Hale, J. Angel, R. Mahmood, S. Foster, J.
Steinweg-Woods, R. Boyles , S. Fall, R.T. McNider, and P. Blanken, 2007: Unresolved
issues with the assessment of multi-decadal global land surface temperature
trends. J. Geophys. Res. accepted.
summarizes these issue, and adds significant new problems with the use of
land surface air temperature trends as part of the construction of a global
average surface temperature trend as used by Rahmstorf and colleagues.
Thus the reported “warming” reported from the Hadley Centre / Climatic
Research Unit data has a warm bias of a significant value (certainly tenths of a
degess) in its construction.
Even more egregious was their selection of the
Willis, J.K., D. Roemmich, and B. Cornuelle, 2004: Interannual variability in
upper ocean heat content, temperature, and thermosteric expansion on global
scales. J. Geophys. Res., 109, C12036, doi: 10.1029/2003JC002260
paper to cite (which documents a strong ocean warming in the 1990s), but
ignores the more recent paper
Lyman, J. M., J. K. Willis, and G. C. Johnson (2006), Recent cooling of
upper ocean, Geophys. Res. Lett., 33, L18604,
which reports on significant recent ocean cooling!
The authors cannot be faulted for bolstering the case for their perspective
of climate change, but by ignoring peer reviewed literature that provides
another perspective, they are grossly misleading the public and policymakers on
our actual understanding of the climate system. As a former Co-Chief Editor of
the Journal of Atmospheric Science, the former Chief Editor of the Monthly
Review, and Chief Editor of the U.S. National Report to International Union of
Geodesy and Geophysics 1991-1994. such a paper would not have been accepted in
the form as submitted until they, at the very least, address these other issues.