Update: In response to a request for further inconsistencies in the AMS Statement, I have reproduced my comment to a colleague of mine
The AMS Statement itself contradicts itself. It writes
“Land surface changes can also affect the surface exchanges of water and energy with the atmosphere. Humans alter land surface characteristics by carrying out irrigation, removing and introducing forests, changing vegetative land cover through agriculture, and building cities and reservoirs. These changes can have significant effects on local-to-regional climate patterns, which adds up to a small impact on the global energy balance as well.”
yet earlier highlights that
“…the dominant cause of the rapid change in climate of the past half century is human-induced increases in the amount of atmospheric greenhouse gases, including carbon dioxide (CO2), chlorofluorocarbons, methane, and nitrous oxide. The most important of these over the long term is CO2…’
It is clear the Statement was not even probably vetted for internal inconsistencies. If they write
“…the dominant cause of the rapid change in climate of the past half century is human-induced increases in the amount of atmospheric greenhouse gases”
and later write
“Humans alter land surface characteristics by carrying out irrigation, removing and introducing forests, changing vegetative land cover through agriculture, and building cities and reservoirs. These changes can have significant effects on local-to-regional climate patterns’
yet dismissing their importance because they add “up to a small impact on the global energy balance ….”
they trivialize, as I read the Statement, their role in climate change.
***********Original Post**********************
The American Meteorological Society has released its Statement
Climate Change – An Information Statement of the American Meteorological Society
where its stated intent starts with
The following is an AMS Information Statement intended to provide a trustworthy, objective, and scientifically up-to-date explanation of scientific issues of concern to the public at large.
Unfortunately, the Statement then goes on to write [highlight added]
It is clear from extensive scientific evidence that the dominant cause of the rapid change in climate of the past half century is human-induced increases in the amount of atmospheric greenhouse gases, including carbon dioxide (CO2), chlorofluorocarbons, methane, and nitrous oxide. The most important of these over the long term is CO2, whose concentration in the atmosphere is rising principally as a result of fossil-fuel combustion and deforestation.
The new AMS Statement on Climate Change focus on primarily CO2 has already been refuted as documented in the National Research Council Report
National Research Council, 2005: Radiative forcing of climate change: Expanding the concept and addressing uncertainties. Committee on Radiative Forcing Effects on Climate Change, Climate Research Committee, Board on Atmospheric Sciences and Climate, Division on Earth and Life Studies, The National Academies Press, Washington, D.C., 208 pp.
and summarized in the American Geophysical Union EOS article
Pielke Sr., R., K. Beven, G. Brasseur, J. Calvert, M. Chahine, R. Dickerson, D. Entekhabi, E. Foufoula-Georgiou, H. Gupta, V. Gupta, W. Krajewski, E. Philip Krider, W. K.M. Lau, J. McDonnell, W. Rossow, J. Schaake, J. Smith, S. Sorooshian, and E. Wood, 2009: Climate change: The need to consider human forcings besides greenhouse gases. Eos, Vol. 90, No. 45, 10 November 2009, 413. Copyright (2009) American Geophysical Union.
where specific evidence was presented that clearly shows that the assumption of the dominance of increased atmospheric concentration of CO2 on altering climate is wrong. In the EOS article we documented that the only non-rejected hypothesis (of the three listed) is
Although the natural causes of climate variations and changes are undoubtedly important, the human influences are significant and involve a diverse range of first-order climate forcings, including, but not limited to, the human input of carbon dioxide (CO2). Most, if not all, of these human influences on regional and global climate will continue to be of concern during the coming decades.
We wrote in the article that
In addition to greenhouse gas emissions, other first-order human climate forcings are important to understanding the future behavior of Earth’s climate. These forcings are spatially heterogeneous and include the effect of aerosols on clouds and associated precipitation [e.g., Rosenfeld et al., 2008], the influence of aerosol deposition (e.g., black carbon (soot) [Flanner et al. 2007] and reactive nitrogen [Galloway et al., 2004]), and the role of changes in land use/land cover [e.g., Takata et al., 2009]. Among their effects is their role in altering atmospheric and ocean circulation features away from what they would be in the natural climate system [NRC, 2005]. As with CO2, the lengths of time that they affect the climate are estimated to be on multidecadal time scales and longer.
The American Meteorological Society itself has a 2010 Statement that contradictions their new Statement on Climate Change. That Statement is titled
Inadvertent Weather Modification – An Information Statement of the American Meteorological Society
Inadvertant weather modification is defined in the Statement as
Inadvertent weather modification is the unintended consequence of an act, either on purpose or accidentally, that results in changes in the weather.
Inadvertant weather modification is clearly part of “climate change”.
The Statement on Inadvertent Weather Modification starts with the text
This statement highlights the causes and possible effects of inadvertent weather modification1 at local and regional scales due to aerosol2 and gas emissions3 and to changes in land use. The known effects can have unanticipated and often undesirable socioeconomic consequences. This statement assesses the impacts of inadvertent weather modification and suggests potential respective actions.
and concludes with
These research efforts on unintended weather modification should be recognized as addressing parts of the broader question of climate variability and change, which crosses geopolitical boundaries. As was the case with acid rain and stratospheric ozone depletion, national and international frameworks should be developed for addressing the related environmental and ethical issues for inadvertent weather modification.
It is clear that in the new AMS Statement on Climate Change they decided to ignore the Inadvertent Weather Modification Statement by the same society! We were precluded from not headlining the Inadvertent Weather Modification Statement as being on climate, but the last paragraph clearly shows it is very much relevant (and broadens quite significantly) what should in the AMS Statement. I am a Fellow of the AMS, and I am very disappointed that the writers of the Statement on Climate Change did not have the courtesy, nor the perspective, to include what was reported in AMS Statement on Inadvertant Weather Modification.
As a final note on the AMS Statement on Climate Change, they also write
climate models have demonstrated skill in reproducing past climates.
Readers of my weblog should know this is an erroneous claim as documented in the peer-reviewed papers that have been summarized most recently in the post
CMIP5 Climate Model Runs – A Scientifically Flawed Approach
I summarize in the post the requirements to make a claim such as “climate models have demonstrated skill in reproducing past climates“, with the text
The first requirement of the CMIP5 runs, before they should even be spending time and money on projections, is that they must skillfully (and shown with quantitative analyses) to
- replicate the statistics of the current climate,
and
- replicate the changes in climate statistics over this time period.
However, peer-reviewed studies that have quantitatively examined this issue using hindcast runs show large problems even with respect to current model statistics, much less their change over time.
I concluded that post with the text with respect to the evidence from the peer-reviewed papers that
These studies, and I am certain more will follow, show that the multi-decadal climate models are not even skillfully simulating current climate statistics, as are needed by the impacts communities, much less CHANGES in climate statistics. At some point, this waste of money to make regional climate predictions decades from now is going to be widely recognized.
It is clear that the new AMS Statement Climate Change is more advocacy by the leadership of the Society, than a balanced presentation of this subject. When evidence contradicts their advocacy role, they conveniently just ignore it.
Judy Curry also has an excellent post titled
AMS Statement on Climate Change
in which I agree with her conclusion where she wrote
“My strong objections to this type of statement by professional societies has been voiced previously. This statement is worse than the previous AMS statement…….In other words, consensus statements get parroted without any actual intellectual examination. In this case, what is the point of the AMS statement. Apparently, to ‘inform the public’ on this controversial issue by appealing to the ‘authority’ of the society.
These Statements (including the one I participated on) are not voted on by the members of the society, nor are the committee members’ names made public. This, along with the absence of an open on-line debate, make this process a sad commentary on a professional society (the American Meteorological Society) which has otherwise done so much for science.
Climate Science: Roger Pielke Sr. 
