In today’s listing of new science papers published by the American Geophysical Union, two papers illustrate quite clearly why the certainty of knowledge expressed by Presidential Science Advisor John Holdren in his testimony before Congress on Thursday is both mistaken and dangerous.

First, a paper published in Geophysical Research Letters outlines a new and reduced estimate of the strength of what scientists call the biological carbon pump. The biological carbon pump is the amount of carbon lost to the atmosphere and ocean systems because it is absorbed by sea life which upon death sink to the bottom of the oceans to form long term sedimentary layers. This pump is a crucial component of all climate models, since it affects the amount of carbon available in the atmosphere and oceans.

Do scientists now know the strength of this pump? To quote the paper’s abstract:

The lack of consensus amongst different methodologies on the strength of the biological carbon pump emphasizes that our knowledge of a major planetary carbon flux remains incomplete.

Second, a paper published in the Journal of Geophysical Letter-Atmospheres attempts to measure whether increased greenhouse gases will increase or decrease the frequency of summer cyclones in the Northern Hemisphere. Their conclusion:

There is no consistency among the models as to whether the frequency of hemispheric-averaged summer cyclones will increase or decrease. For some subregions the sign of the trend is consistent across the vast majority of models, but even then there is a large spread in the magnitude of the trends. The general lack of consistency among models indicates that care is required when interpreting projected changes in summer weather systems.

The science sure appears “settled,” doesn’t it? Both papers attempt to address key claims made by global warming advocates. Both papers fail to do so, and admit bluntly in their abstracts that the science remains unclear and that care must be taken before any firm conclusions are reached.

Climate science is a complex field, with many conclusions and areas of uncertainty. Though there is a lot we do know, there is far more that we as yet do not understand. For any scientist or politician to claim a certainty of knowledge, as Holdren did in his testimony to Congress, does a disservice to science. To then use that claim as a justification for passing laws to restrict the freedom of Americans is downright unconscionable.