Do you have any examples of downvote-bombing simple claims that climate change is real? I'd be beyond surprised to find out this phenomenon is real, even just based on the demographic prior of HN.

No worries if not, I get that it's not a trivial ask to dig up an example.

Not climate change. But three days ago this is a bit strange. Article regarding to anti-vax and astroturfing. First submission flagged https://news.ycombinator.com/item?id=27946430 Lots of comments saying it is being artificially vote inflated. Second submission more objections https://news.ycombinator.com/item?id=27951293 stating conspiracy voting. Not sure what to make of it. And just one example.

Thank you for the links, but I was asking about the (since-edited-out) claims that these comments were being downvote-bombed. Submission ranking is considerably more complicated, and is not what I was asking about.

Things generally don't stay on the front page for long. Your claim sounds pretty paranoid.