When you’re in the biodiversity conservation biz for any significant length of time, you inevitably develop a thick skin to grim pronouncements of ecosystem collapse from the scientific community. It’s a coping mechanism. Coral reef conservation, in particular, is not a place for overly delicate sorts. Nary a week passes without some fresh obituary being written about reefs. And this week is no exception. But even this news gave me pause.
Increasing CO2 levels do more than just raise temperatures that produce bleaching in coral reefs. The dissolved CO2 changes the ocean chemistry, acidifying the water.
This has large effects on the sustainability of any organism that requires carbonate chemistry to create a hard shell. Too large a change in the acid levels of the oceans could be devastating.
This has been seen in the past during large extinction events. But today’s changes in acidification are unprecedented over the last 50-60 million years. As I quoted before, from Andy Ridgwell at the University of Bristol:
The acidification of the ocean today is bigger and faster than anything geologists can find in the fossil record over the past 65 million years. Indeed, its speed and strength — Ridgwell estimates that current ocean acidification is taking place at ten times the rate that preceded the mass extinction 55 million years ago — may spell doom for many marine species, particularly ones that live in the deep ocean.
“This is an almost unprecedented geological event,” says Ridgwell.
The Paleo-Eocene Thermal Maximum was the last period of extreme temperatures on the Earth. It was a rapid event, taking less than 20,000 for global temperatures to rise 6°C. To think that current conditions are rising faster is not good news.