This story  is legitimately tragic, but it's far from the first case of climate change delusion. Have they never heard of Benny Peiser ? Larry Solomon ? Tim Ball ? The Viscount Monckton of Brenchley ? Bob Carter ?
Of course, these guys may not be delusional. They may just be lying. But that would involve a judgment rather than a diagnosis .... And either way, a certain sort of sickness abounds.