[Coral-List] Basic Question. Simple Answer ?

[Fishy]

Greetings all,
My sincerest apologies for wasting time and bandwidth with what Im sure
is an eye-rolling question for you all.
I have tried to answer this question myself but have found 
insufficient research
to back up my response.
Can anyone help me ?

"Why are marine biologists so worried by a forecast global warming 
rise of 1.4-5.8 degrees occurring over the next century, when the 
coral obviously survived a far more rapid and greater increase (~7 
deg over 10 years) about 15000 years ago (Younger Dryas) ?"

My response is this:

1. Greenland never had hard corals and the temperature change was 
probably local not global.
2. Just because some corals survive, doesnt mean losing massive 
diversity was a minor effect.
3. Tropical coral reefs have been stable for a long time now - sudden 
change will be disasterous.

But thats the best I can offer.

Hope someone out there has some patience.
Sorry again.

Chris.