Revelation 8 describes the precursors to the great tribulation with the opening of the seventh seal and the sounding of the trumpets. It begins with an earthquake. First Trumpet: Vegetation Struck, Second Trumpet: The Seas Struck, Third Trumpet: The Waters Struck, Fourth Trumpet: The Heavens Struck; one ecological disaster after another.
Haggai 1 is about having the right priorities. God had commanded the inhabitants of Jerusalem to rebuild His house. When pointed out their wrongful ways the people obeyed.