In his letter of March 10, John Farley categorizes global warming "deniers" as individuals or organizations whose basis for denial is either political or economic.

Without a doubt, the debate over global warming is very highly politicized. However, to ascribe political and economic motives solely to "deniers" is to misrepresent the current realities of scientific research.

I suspect professor Farley has been in academia sufficiently long to recognize that obtaining federal funding for research is a highly political process where the personal agendas and relationships of the career bureaucrats responsible for administering contracts frequently have as much to do with what grants are awarded as do the merits of the proposed research.

As a consequence, the results of research funded by such federal agencies as the National Renewable Energy Laboratory, the EPA, or NSF should not necessarily be viewed as any more objective than work funded by ExxonMobil. One need only read the current solicitations coming out of government agencies involved in climatological research to begin to suspect the directed nature of projects funded by these entities.

As scientists, we like to characterize our work as objective and dispassionate. But far too often career pressures, personal motives, and/or financial considerations interfere with scientific objectivity.

For example, a climatologist investigating correlations between global temperatures and solar output or miniscule shifts in the Earth's axis of rotation will have opportunity to present his data to an audience of a few dozen fellow scientists at an unheralded conference attended by a small number of specialists. He might subsequently publish his work in a refereed journal where it would be read by, at most, a few thousand scientists worldwide.

However, suppose that same researcher publishes a paper correlating melting polar ice caps with worldwide combustion of coal in power plants. Suddenly, our previously obscure climatologist has his results broadcast worldwide by The Associated Press, he gets to share a podium with Al Gore and assorted Hollywood glitterati, and he's invited to spend a high-profile week helping draft the next report of the Intergovernmental Panel on Climate Change.

To argue that such influences have no effect on a scientist's work is to deny human nature. Professor Farley no doubt remembers the cold fusion announcement in the mid-1990s, when the desire for publicity and funding seriously clouded the judgment of a number of otherwise reputable and respected scientists.

The recent IPCC report has been widely heralded as the "nail in the coffin" that firmly establishes the connection between global warming and human activity. But isn't some skepticism justified when an organization obtains a result that ensures its continued funding and existence -- and provides opportunity for the 2,000 or so invited scientists as well as the IPCC staff to spend a week in Paris at their institution's expense?

In truth, the IPCC has only released the executive summary of its report, portions of which have been widely publicized in the popular press. The full text of the report, with any qualifications and equivocations, will not be available until mid-year.

Average global temperatures are, without argument, increasing. The increase in temperatures since 1850 that professor Farley cites is not a subject of controversy. However, when average temperatures based on tree ring data and historical records are viewed on broader time scale, most if not all of the increase since 1850 is seen to represent the recovery from a period of abnormally low average temperatures -- commonly referred to as the "Little Ice Age" -- that extended from the 1300s to the early 1800s.

These same data indicate that global temperatures have only recently returned to levels that were the norm in the Middle Ages.

On an even broader time frame, measurements of oxygen-18 levels in marine fossils -- an indicator of average temperatures when the fossil bed was deposited -- point to a roughly 100,000-year cycle of warming and cooling, with the present day corresponding to the most recent peak in the warming cycle.

Of course, these observations by themselves do not refute a connection between human activity and global warming. However, they do point to the possibility that mechanisms other than human activity might be contributing to -- or even primarily responsible for -- the present warming trend.

Unfortunately, it would appear that the global warming discussion has moved out of the technical arena and into a political one where both sides rely less on careful analysis of observations and more on a dogmatic acceptance of a viewpoint that rejects any evidence not in agreement with a preconceived belief.

The local and global consequences of a warming climate will potentially be dramatic, maybe even dire in some instances. However, absent a thorough understanding of all the mechanisms behind the present warming trend, mankind runs the risk of finding that a cure based on ignorance is worse than the perceived disease.

Global warming is still a subject that is best addressed through discussion and debate among the technically competent, not the semi-hysterical public rants of Al Gore and any other celebrities seeking "face time" in front of a media that has long since lost its objectivity on this issue.

James D. Hodge, who holds a Ph.D. in Materials Science, is chief technical officer with Peak Energy Solutions, a battery company in Henderson.