Regarding water temperature, there are two big changes when you move away from the equator: 1. Temperatures drop. 2. Temperature variability increases. (Seas

Regarding water temperature, there are two big changes when you move away from the equator: 1. Temperatures drop. 2. Temperature variability increases. (Seasons are more meaningful away from the equator.) The second issue, of temperature variability, is a main problem that prevents reefs from migrating away from the equator in response to global warming. The corals can't tolerate a wide range of temperatures. The other problem, as you say, is the time frame. Reefs are built up over thousands of years, and we are warming and acidifying the oceans over mere decades. (And ocean acidification isn't helped at all by moving away from the equator.)