Destruction of the temple seems inevitable. Morna Hooker in her excellent The Gospel according to Mark, suggests two possibilities: one, Rome will get fed up with the threats of revolt by the Jews; or, two, Divine judgment will punish the Jews because they have not been listening to what this messenger has been telling them (for other examples, see Jeremiah 7:14; 26:6; Micah 3:10).
Jesus warns them, "People claiming to be followers will say things that are not true to what I've been telling you." and "Wars will come, as will earthquakes and famine." Hooker points out that these catastrophes were understood as a model of divine punishment (wars: Jeremiah 4:17-22); Zechariah 14:2; earthquakes: Isaiah 13:13; Jeremiah 4:23-27; famines: Isaiah 14:30; Joel 1:1-12).