Coral will due fine with the ocean becoming minutely less base. Coral evolved when CO2 was an order of magnitude higher than current levels, and thrived during the Eemian 130k years ago when temperatures were higher than current. Coral also has low generation times and rocks an extremely R selected reproduction strategy which means it's one of the least likely species to be adversely affected by changing climate.

The ignorance chemistry, biology, and natural history required to fall for the histrionics of climate change/global warming is ill becoming of nerds. It requires a serious hatred of the biosphere to work against raising CO2 to the plant friendly 1500ppm utilized in greenhouses and marijuana growing basements. I'll give you the benefit of the doubt and assume ignorance is your excuse.

It rose over 300 feet at the end of the last ice age, humanity thrived. Sucks if you own beachfront property but not a problem for most of humanity, let alone an extinction level event. Ignorance of natural history is required to believe this scaremongering.

a mere 15 million years ago CO2 levels were 4 times higher, average temperature was several degrees warmer, and seas were 200 feet higher.
The earth was an unihabitable wasteland!
no, wait, it was lusher and more fecund than now.
It's a reasonable hypothesis that returning the CO2 levels to their prehistoric norms could raise temperatures back to the previous levels. That it would cause extinction level events for humanity is ridiculous chicken little bullshit.

Global warming if it ever kicks in should increase the areas where cacao cultivation is feasible, thus increasing our supply of chocolate.
Burn some coal for heat/electricity today to increase tomorrow's chocolate supply, it's a WIN-WIN!

I know a repeatable experiment.
Greenhouse A. maintain at 100 ppm co2
Greenhouse B. maintain at 400 ppm co2
Greenhouse C. maintain at 1600 ppm co2
Grow pot in all 3 greenhouses. It dies in A, grows normally in B, And grows faster in C
Simple reproducible science. The vast majority of plants grow better, and can grow in more marginal areas, with CO2 concentrations like they were 15 million years ago.
The green choice is to increase co2 output massively

The Mongols invaded Russia in the winter so that they would have an easier time moving supplies on the frozen rivers with sledges. No player in the tech sector is as bad ass as Mongols of course.