Leading up to Rio+20, on April 25th the United Nations hosted “Healthy Oceans: Charting A New Course,” a panel discussion which brought together a range of experts to discuss the fate of the world’s oceans and what can be done to protect them.

A new study in Science finds that the oceans may be acidifying faster today from industrial emissions than they did during four major extinctions in the last 300 million years when carbon levels spiked naturally.

Oceans turned more acidic during a period of great warming some 56 million years ago, causing an extinction of bottom-dwelling marine species known as foraminifera, a scenario that may be happening again now, only much more quickly.

“The world needs to awaken itself to the looming catastrophe of global warming,” said Jeffrey Sachs, Director of the Earth Institute, at a recent meeting in Muscat. “We must provide a safe operating space where vested interest and lobby-driven policies will not see the world marching into disaster.”

Coral reefs, the “rainforests of the sea,” are some of the most biodiverse and productive ecosystems on earth. But tragically, they are in crisis.

Bärbel Hönisch, an expert on ocean acidification at Columbia, will speak after a screening of the film “A Sea Change” this Thursday.