It's deniers who rely on opinion
The author of the letter seeks to imply that "science" is available to back-up all the claims made in his communication and that views to the contrary are merely "opinion."
Fortunately, the author of the letter provides a helpful link to his "independent analysis" which has been "published" on the Internet! If one looks at this "independent" research, one immediately notices it is extremely reliant on a few key sources of "information" on the subject. These are, The Heartland Institute, The Science & Environment Policy Project and several individuals closely tied to them. Would any readers here be surprised to learn that most of these "scientific" organizations receive vast amounts of their funding from other organizations with direct links to the petrochemical industry? There are also past links to Philip Morris and The Tobacco Institute, which funded research to call into question "science" and its basic ability to analyze just about anything dating back to the 1990s. This letter appearing in Monday's Herald is just another piece of this long-running and stunningly self-serving effort to undermine real science by those with an enormous vested financial interest in maintaining the status quo from which they profit so handsomely.
My only other point would be to call attention to another "research" endeavor of the author of the letter claiming to know so much about "science." That would be his available Internet "publications" and lectures in the field of "Creationism," and his call for its inclusion in school curricula around the world.