Having title under name doesn’t signify expertise
Having checked the bona fides of the climate change denier and his organization (which I do for most letter writers who use a title and organization), I find that the ICSC and the other cited organization, the NIPCC, are corporate shills for climate change denial.
To say that 7.5 billion humans have no effect on climate and weather is the same as saying that humans don’t cause any forms of pollution around the planet in any environment. The buildup of these pollutants over time has had a profound effect on the planet’s health and its occupants.
The founder of the cited NIPCC, despite his scientific credentials, also wrote a paper stating that secondhand tobacco smoke posed no health risk to those exposed. I would extrapolate from this that there was probably money involved from the tobacco lobby trading on scientific credentials. No self-interest or sellout there!
I would suggest that more people be more curious about checking information, especially when writers throw a title under their name that seems to confer an essential expertise to affirm the validity of a stated position.