The Only Time in History the Entire Ocean Almost Died

Look at an ocean so full of life that it seems finished, then watch about nine out of every ten species in it disappear. This is the end of the Permian, 252 million years ago, the worst extinction the sea has ever known. The water stays wet and the planet stays in one piece. But the ocean turns too hot, too acidic and too short on oxygen to keep its animals alive. So how does the sea itself become the weapon, and what can survive when it does? The film starts in the last good days: reefs of sponges and old coral groups, the final trilobites, early shark cousins, and shelled animals clamped to the bottom. Then it follows the cause step by step, from the Siberian Traps, lava covering about 770,000 square miles and burning through coal, to the carbon dioxide that warms the water, drains its oxygen and makes shells harder to build. It ends with the survivors, the long recovery, and what this ancient disaster tells us about the stacked stresses on today's oceans.