At best, shaping messaging of policy, at worst, propaganda. He isn't preventing any scientists from publishing anything. Even if he did scrub a term from the entire site personally, that isn't censorship. It isn't illegal to talk about Climate Change.
I agree it's more equilant to the astroturfing done by the Chinese net hoards than censorship. They are changing the message if the it was real censorship this article itself would not be readable