If a climate scientist used “It sure was hot out at the beach yesterday” as an example of anthropogenic climate change, I don’t think you need any special expertise to point out that that is not a good argument for the point. @coderay isn’t saying it wasn’t hot at the beach or that climate change isn’t happening, just that some of the particular examples given do not support the conclusions.
Dogpiling on anyone who critiques any aspect of a manifesto is not the way to encourage productive communication. If I don’t have the authority to talk about things that I don’t have direct personal experience with, what the fuck are we even having this conversation for? “Sit down, shut up, and listen” is not what peers open an interaction with.