The Sixth Great Extinction: A Breakdown

What’s the issue?

Published last week, the Caballos Report reveals how extinction rates for vertebrates in the 20th century are up to 100 times higher than would be expected without human impact.   Rather than the expected extinction of nine species over the years since 1900, a massive 468 species, consisting of mammals, birds, reptiles, amphibians and fish, now cease to exist. The report also notes how their estimates have been conservative, not accounting for ocean acidification or global warming.

What’s the problem?

Scientists are alarmed by these findings, and rightly so. The changes that have occurred to the earth’s biosphere over the past decade have been described in The Guardian as ‘weird, in planetary terms’ due to their unprecedented nature. While previous mass extinctions have been triggered by events such as volcanic eruptions, the impact of an asteroid or the effects of rapid climate change, the study exposes the real reason behind what Caballos called this ‘massive loss of species’.

Who is to blame?

Homo Sapiens, or to put it more plainly: we are. Our top predator status on land and at sea has caused irreversible damage to earth’s eco-systems. Scientist Vaclav Smil, of the University of Manitoba, has stated how humans now make up (by mass) a third of land vertebrates, while the animals we eat (cows, pigs, sheep etc) account for the other two-thirds. This means, as a species far removed from the days of Noah’s Ark, we have managed to collectively marginalise all other wild animals that are of no use to us. They have then become victims of our relentless abuse of the environment, via pollution and deforestation, which ruins habitats and turns animals into commodities.

Is this as bad as it seems?

Yes, and no. On one hand we have Pope Francis and Barack Obama finally getting involved this week making statements to the world concerning our behaviour. Yet we’re still in a dire position with the report suggesting that pollination by bees could be lost within three human generations. As Stanford University Professor who co-wrote the study, Paul Ehrlich said: “We are sawing off the limb we are sitting on”.

Blog post by Hannah Coles

(Image courtesy of dan at FreeDigitalPhotos.net)