Friday, June 11, 2010

Global Warming Science: A Cross Examination

A cross examination of global warming science conducted by the University of Pennsylvania’s Institute for Law and Economics has concluded that virtually every claim advanced by global warming proponents fails to stand up to scrutiny.

The cross-examination, carried out by Jason Scott Johnston, Professor and Director of the Program on Law, Environment and Economy at the University of Pennsylvania Law School, found that “on virtually every major issue in climate change science, the [reports of the UN’s Intergovernmental Panel on Climate Change] and other summarizing work by leading climate establishment scientists have adopted various rhetorical strategies that seem to systematically conceal or minimize what appear to be fundamental scientific uncertainties or even disagreements.”

Professor Johnson, who expressed surprise that the case for global warming was so weak, systematically examined the claims made in IPCC publications and other similar work by leading climate establishment scientists and compared them with what is found in the peer-edited climate science literature. He found that the climate establishment does not follow the scientific method. Instead, it “seems overall to comprise an effort to marshal evidence in favor of a predetermined policy preference.”

The 79-page document, which effectively eviscerates the case for man-made global warming, can be found here.

GLOBAL WARMING ADVOCACY SCIENCE: A CROSS EXAMINATION
By Jason Scott Johnston
Robert G. Fuller, Jr. Professor and Director,
Program on Law, Environment and Economy
University of Pennsylvania Law School
Abstract
Legal scholarship has come to accept as true the various pronouncements of the Intergovernmental Panel on Climate Change (IPCC) and other scientists who have been active in the movement for greenhouse gas (ghg) emission reductions to combat global warming. The only criticism that legal scholars have had of the story told by this group of activist scientists – what may be called the climate establishment – is that it is too conservative in not paying enough attention to possible catastrophic harm from potentially very high temperature increases.
This paper departs from such faith in the climate establishment by comparing the picture of climate science presented by the Intergovernmental Panel on Climate Change (IPCC) and other global warming scientist advocates with the peer-edited scientific literature on climate change. A review of the peer-edited literature reveals a systematic tendency of the climate establishment to engage in a variety of stylized rhetorical techniques that seem to oversell what is actually known about climate change while concealing fundamental uncertainties and open questions regarding many of the key processes involved in climate change.
Fundamental open questions include not only the size but the direction of feedback effects that are responsible for the bulk of the temperature increase predicted to result from atmospheric greenhouse gas increases: while climate models all presume that such feedback effects are on balance strongly positive, more and more peer-edited scientific papers seem to suggest that feedback effects may be small or even negative. The cross-examination conducted in this paper reveals many additional areas where the peer-edited literature seems to conflict with the picture painted by establishment climate science, ranging from the magnitude of 20th century surface temperature increases and their relation to past temperatures; the possibility that inherent variability in the earth’s non-linear climate system, and not increases in CO2, may explain observed late 20th century warming; the ability of climate models to actually explain past temperatures; and, finally, substantial doubt about the
methodological validity of models used to make highly publicized predictions of global warming impacts such as species loss.
Insofar as establishment climate science has glossed over and minimized such fundamental questions and uncertainties in climate science, it has created widespread misimpressions that have serious consequences for optimal policy design. Such misimpressions uniformly tend to support the case for rapid and costly decarbonization of the American economy, yet they characterize the work of even the most rigorous legal scholars. A more balanced and nuanced view of the existing state of climate science supports much more gradual and easily reversible policies regarding greenhouse gas emission reduction, and also urges a redirection in public funding of climate science away from the continued subsidization of refinements of computer models and toward increased spending on the development of standardized observational datasets against which existing climate models can be tested.

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