Book: The sixth extinction

Mass extinctions have occurred on the planet five times already and we are heading for another one. But this time we have no one to blame but ourselves. Robert Edis welcomes a measured contribution to discussion of the crisis.

The Sixth Extinction: An unnatural history
By Elizabeth Kolbert
Bloomsbury (2014),
RRP $39.99 (Hardback)

When it comes to mass extinctions, survival of the fittest becomes survival of the luckiest. Where evolution slowly changes the biological make-up, a catastrophic event can make all that adaptation irrelevant, subsequently impoverishing genetic capital.

It has happened five times so far. The first, 439 million years ago when the supercontinent Gondwana drifted south towards the polar region, led to the loss of two-thirds of all marine invertebrates. The most recent, the extinction of the dinosaurs 66 million years ago, was probably due to an asteroid impact that changed their world forever.

As Elizabeth Kolbert, a staff writer at the New Yorker, explains, we are amidst another – the Sixth Extinction – and this time we have no one to blame but ourselves.

While it is a gloomy prognosis, the journey she takes to get us there is an exciting one, with careful research, and sometimes adventurous reporting on the main aspects of this slow-boil calamity.

Kolbert weaves a story around a single species, either extinct or as good as, for each chapter which covers a particular aspect of the sixth extinction brought on by mankind’s exploitation and disruption of natural systems. Overhunting, habitat destruction and fragmentation, the increase of nitrates and phosphates to aquatic systems, introduced organisms, ocean acidification and climate change are all covered, but without shrill or unnecessary doom-saying.

Along the way Kolbert introduces us to several scientists that she visits in fabulous locations for whom she engenders admiration, fondness, and sometimes amusement.

While the prospects are undeniably bleak, crisis is also a time for heroes.

The book is permeated with this humanising of the scientific process. Astute observations of some of the most important ecological breakthroughs are distilled to their essence: curiosity, observation, happenstance, and challenging established thinking. As well as many being wrong.

The approach is reminiscent in tone of Dava Sobel’s careful explanation of how the greatest problem in navigation was solved in Longitude, in the way it unpacks how science and technology work.

Loss of habitat through logging is just one way humans are hastening the demise of many species. – Getty Images

While the prospects are undeniably bleak, crisis is also a time for heroes. Kolbert introduces us to people trying to preserve critically endangered species and ecosystems, many with disheartening prospects of success. We also are given tales of sources of inspiration, such as a Tin Tin comic that inspired a seven-year-old to go on to become a palaeontologist, or how the extinction of the great auk motivated lobbying
for England’s first wildlife protection act.

The book contains several stories of people becoming convinced of the seriousness, speed and scale of the changes. A former Chief Scientist at the Australian Institute of Marine Science declares that, “a few decades ago, I myself would have thought it ridiculous to imagine that reefs might have a limited lifespan. Yet here I am today...utterly convinced that they will not be there for our children’s children to enjoy”.

Kolbert resists the temptation to advocate specific remedies that may help us avoid this catastrophe, but does offer general observations. Reducing carbon dioxide concentrations would be a useful start, and local protections are also important.

The Sixth Extinction is an easy and fascinating read, with many interesting scientific and historical facts to entertain and fuel conversations of readers from all backgrounds. There are some minor irritants: the use of imperial units may frustrate some younger readers and the crush-like enthusiasm for some of the researchers may weary older ones.

But it is an overarching and measured contribution to discussion of the crisis we have brought on ourselves.

As she has acknowledged, the problem is not one but many.

“We’re not just warming the world, we’re cutting down the rain forest. We’re not just cutting down the rain forest, we’re moving invasive species into the rain forest.

“We are the asteroid now. The asteroid also had a lot of different effects, and it didn’t end too well.”

Robert Edis is associate professor of the Melbourne School of Land and Environment, University of Melbourne
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