A jeremiad is a long literary work, usually in prose, but sometimes in verse, in which the author bitterly laments the state of society and its morals in a serious tone of sustained invective, and always contains a prophecy of society's imminent downfall.
Also of interest: obloquy, philippic.
jeremiad = A tale of sorrow, disappointment, or complaint; a doleful story; a dolorous tirade. Synonyms includes: tirade, diatribes, fulmination, harangue.