Most corals do fine with the water a little warmer. This is a solution in search of a problem, typical of the academy today.
During the MMCO (Middle Miocene Climate Optimum) created temperate climates throughout much of the world — as much as 4 to 5 degrees Celsius (or 7 to 9 degrees Fahrenheit) above today’s average temperatures. Life flourished on earth.
The coral reefs did just fine. As habitat changes the coral will simply grow in different areas that become ideal for it.
"...a solution in search of a large pile of Grant money!"