What makes temperature induced die off significant is that they’re essentially instantaneous: any part of the reef that exceeds some critical temperature dies completely and immediately. The core problem is the temperature increases are far faster than can be grown away from.
Acidification is slower but persistent and inescapable. It attacks existing coral and prevents new growth.
> any part of the reef that exceeds some critical temperature dies completely and immediately.
Typically exceeding CTmax results in bleaching, the expulsion of symbiotic microalgae from the animal polyps, and there is a window of weeks to months in which they will return if temperatures decrease. In the terrible Great Barrier Reef bleaching years of the past decade where individual reefs were facing near complete bleaching, many have made full recoveries.
Worth noting coral reefs are highly diverse, even with very high mortality of corals there are crustose coralline algaes and other habitat building species still at work so the reef doesn't die completely, and 'weedier' coral species start ecological succession quickly.
To your point though these are novel and trying times for low latitude reefs, at least historically speaking.
What makes temperature induced die off significant is that they’re essentially instantaneous: any part of the reef that exceeds some critical temperature dies completely and immediately. The core problem is the temperature increases are far faster than can be grown away from.
Acidification is slower but persistent and inescapable. It attacks existing coral and prevents new growth.