The Sixth Extinction

The Guardian newspaper voted the Sixth Extinction: An Unnatural History, by the award winning journalist Elizabeth Kolbertthe best non-fiction book of all time. It isn’t, but it is still worth reading.

Life has existed on our planet for around four billion years but mass extinctions seem to have taken place on our earth every twenty-six million years or so. Although everyone (more or less) agrees that a meteor strike caused the fifth mass extinction (of the dinosaurs, amongst others), geologists disagree as to what caused the others. Perhaps other meteor strikes; perhaps natural climate change.

Pretty much everyone, however, agrees that mankind is the cause of the sixth mass extinction that we are currently living in a geological era that geologists call the “Anthropocene”. Ms Kolbert writes,

The Anthropocene is usually said to have begun with the industrial revolution, or perhaps even later, with the explosive growth in population that followed World War II. … But the megafauna extinction suggests otherwise. Before humans emerged on the scene, being large and slow to reproduce was a highly successful strategy, and outsized creatures dominated the planet. Then in what amounts to a geologic instant, this strategy became a loser’s game. And so it remains today, which is why elephants and bears and big cats are in so much trouble…Though it might be nice to imagine there once was a time when man lived in harmony with nature, it’s not clear that he ever really did.

Man destroys biodiversity in three ways: first by eating it; second, by encroaching on—and stealing—its territory; and third by accident–spreading alien species or bacteria. Ms Kolbert writes,

“During any given twenty-four hour period, it is estimated that ten thousand different species are being moved around the world in ballast water. Thus a single supertanker (or for that matter a jet passenger) can undo millions of years of geographic separation.”

Meanwhile, the tsunami that struck Japan in 2011 has carried almost 300 species of sea life  across the Pacific Ocean to the west coast of the United States. In what could be the longest maritime migration ever recorded, an estimated one million creatures – including crustaceans, sea slugs and sea worms – made the 7,725km journey on a flotilla of tsunami debris.

Introducing alien species (including bacteria) into new areas can quickly wipe out native fauna that have no historical resistance. Ms Kolbert gives two examples -frogs in Central America and bats in North America – but there are millions of others. This process began one hundred and twenty thousand years ago when Homo Sapiens began its migration out of Africa, (arguably) wiping out the Neanderthals on the way (after mating with them first).

The process of extinction has been going on for so long now it seems all but inevitable that it will continue until the only animals that will be left on the planet will be the ones that we eat—or the ones that we can marvel or laugh at in zoos, or on YouTube. Looked at in this way, you might be tempted to think that the forces behind this are so powerful that we are powerless to stop it.

And if you think this mass extinction is not your fault, Ms Kolbert has this to say,

If you want to think about why humans are so dangerous to other species, you can picture a poacher in Africa carrying an AK-47 or a logger in the Amazon gripping an axe, or better still, you can picture yourself, holding a book on your lap.

And in case you think that it doesn’t matter if the world loses a few species of fogs or bats, Ms Kolbert adds,

The anthropologist Richard leaky has warned that Homo Sapiens might not only be the agent of the sixth extinction, but also risks being one of its victims.

So we are all doomed; we will take the world’s biodiversity with us. And there is nothing we can do about it.

But wait a minute; aren’t we already doing something about it?

Just this month, a convention came into force to prevent the transfer of potentially invasive species in ballast water, one of the many problems that Ms Kolbert wrote about in her book. Ballast water must now be treated before it is unloaded into a new location, so that any micro-organisms or other small marine species are destroyed.

Last month, the International Union for Conservation of Nature (IUCN) – the global standard for assessing extinction risk – announced that the conservation status of the snow leopard  has been improved from “endangered” to “vulnerable”. The species still faces serious threats from poaching and habitat destruction, but at least it is a step in the right direction.

Perhaps even more optimistically, last month saw the 30th anniversary of the signing of the Montreal Protocol for the preservation of the earth’s ozone layer. Thanks to the treaty, over 98% of ozone-depleting substances have been phased out globally to date. Without the treaty, the hole in the Antarctic ozone would have been 40% larger in 2013. And what’s more, the global health and economic benefits of the treaty are expected to amount to US$2.2 trillion, as a result of averted damages to agriculture, fisheries and materials.

Charles Darwin once wrote, In the long history of humankind, those who learned to collaborate and improvise most effectively have prevailed.

The Montreal Treaty is an example of what mankind can do when we work together. The Paris Agreement is another. We can fix this!

Image courtesy of Pixabay

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