In his Dec. 18 op-ed "How to Manufacture a Climate Consensus," Patrick J. Michaels of the Cato Institute falsely claims that work by him (and other fossil-fuel-funded climate change contrarians) has been unfairly blocked by me and others from appearing in mainstream science journals because the peer review process is supposedly biased against climate science deniers.

In truth, the only bias that exists at such publications is for well-reasoned writing that is buttressed by facts.

That is why climate skeptics such as Richard Lindzen of MIT or John Christy of the University of Alabama - who are widely regarded as credible and whose work contributes meaningfully to the scientific discourse - have no problem publishing their work in mainstream scientific journals.

And what about those who are not being published? Every scientist dealing with a major public issue must decide if he or she is going to be a scientist or a de facto politician.

Mr. Michaels and many climate science deniers have opted for the latter course of action. For example, presidential science adviser John Holdren notes that Mr. Michaels "has published little if anything of distinction . . . being noted rather for his shrill op-ed pieces and indiscriminate denunciations of virtually every finding of mainstream climate science." This makes Mr. Michaels a perfect candidate for a Wall Street Journal op-ed and a decidedly poor submitter to a serious scientific journal.

Society relies upon the integrity of the scientific literature to inform sound policy. It is thus a serious offense to compromise the peer-review system in such a way as to allow anyone - including proponents of climate change science - to promote unsubstantiated claims and distortions.

The good news is that it is not happening today in relation to either climate scientists or the deniers of climate science. Men and women who have dedicated their lives to advancing science need not apologize for keeping their rigorous professional journals free of the pollution of what is purely politics.

Michael E. Mann

Professor, Meteorology Department

Penn State University

Director, Penn State Earth System Science Center

University Park, Pa.

WSJ editor's note: Several weeks ago, we invited Mr. Mann to write a feature explaining his email exchanges that were revealed as part of the University of East Anglia Climatic Research Unit's document disclosure. He declined.