How does this near extinction compare to previous ones?
We have scientific observation of corals, and of coral reefs, that goes back just a few decades. We also have their fossil record of the last 500 million years, including huge climate changes and the documented extinction/rise of various coral subspecies. And then we have people who claim to know with dogmatic certainty that corals are massively dying right now, that they cannot adapt to any climate change -- regardless of the full scientific context.
If we know so much as to make such gloomy, specific predictions -- please show me detailed scientific documentation of the diurnal cycle of corals and their symbionts, with exact minute-by-minute measurement of the day-and-night changes in the photosynthesis, the amount of CO2 in the water, and the productivity of each coral and symbiont. Then provide the same for each day across seasonal changes in water temperature, abundance of sunlight, and CO2 fluctuations. After that, can you indicate this: what are the specific concentration of atmospheric CO2, global sea levels, and ocean temperatures that you will accept as the standard to declare there is no risk of extinction? can these numbers ever change over time and corals would continue to thrive?
The actual science directly contradicts the alarmist speculation spread by unscientific media reports and professional purveyors of modern eschatology.
Not only that, but the ocean is rising due to land-based glaciers/ice melting, the continental rebound involved from the reduced ice load, and yet more: the warming ocean is less dense and expands. The rising seas along with other factors mentioned also puts pressure on coral reefs, as they often cannot grow fast enough to catch up with that sweet-spot near the ocean surface!
Literally two comments above.