While saving a species in captivity prevents its annihilation, it takes an extraordinary effort to return it to the wild. In her Pulitzer Prize-winning book The Sixth Extinction, Elizabeth Kolbert places the present extinction in line with the previous five. She recounts her personal witness to this loss, the studies undertaken to understand its causes, and the attempts being made to save just a few species. Extinctions great and small happened before the Cambrian period, but conditions on Earth then were so different that they have little to teach us about the threats to life today. By contrast, the five mass extinctions since then – when at least 75% of all species on land and in the seas disappeared – are the subject of active research.Ī far-reaching extinction event is happening right now. The Great Dying is one of five mass extinctions since the “Cambrian Explosion” of about 500 million years ago, when modern animal life first took shape. The result was even more cataclysmic than the later extinction of the dinosaurs. The seas became spiked with acid and the air was filled with poisonous gas. During the end-Permian mass extinction event, also known as “The Great Dying,” oceans absorbed vast quantities of carbon dioxide from the air, depleting the oxygen and triggering a world-wide bloom of a sulfurous type of anaerobic bacteria. This deadly chemical change happens when sulfur-producing organisms are given a chance to thrive in seawater. The air for miles around fills with a noxious odor. Around 225 million years ago, during the largest extinction event in Earth’s history, this was the condition of all of the world’s oceans.Ī NASA aerial photograph of the iridescent ocean off the west coast of Africa. Humans are the agents of this extinction, and we can make it stop.Īt times long stretches of the sea off the west coast of Africa turn a milky white, then an iridescent shade of jade green. Any marine creature that can do so crawls onto land to escape the water which has become laced with hydrosulfuric acid. Hydrogen sulfide gas – heavier than air, foul, and poisonous – bubbles out of the sea. We are now facing a sixth mass extinction - the current spate of plant and animal loss threatens to eliminate 20% to 50% of all living species on earth within this century. Marine ecosystems essentially collapsed, and about 75% of all plant and animal species disappeared. The most recent occurred some 66 million years ago when an asteroid collided with earth, wiping out the dinosaurs and dramatically changing the biodiversity of life on our planet.

Our planet has experienced five mass extinction events in the past half billion years. Featured Book The Sixth Extinction An Unnatural History

The sixth great extinction book