Climate Change Book Review: Under a Green Sky

Ever seen a greenhouse extinction? It looks like this.

WHO: Peter D. Ward (Earth and Space Sciences, College of the Environment, University of Washington, WA)

WHAT: Under a Green Sky: Global Warming the Mass Extinctions of the Past and What They Can Tell Us About Our Future

WHERE: Your local bookstore, your local library, etc.

WHEN: Published 2007

I’m taking a moment away from research papers to talk about a book I just finished reading (yes, I read climate change non-fiction as well as climate change research papers – I am that nerdy). Now, when someone says Palaeontologist, not only do I struggle to type it, I also don’t immediately think ‘great writing style’ – no offence to all the budding Palaeontologist/authors out there!

So the fact that Peter Ward has a really evocative style of writing that was able to transport me to the various digs and periods of ancient history that he studies, was one of the reasons I wanted to write about this book. Additionally, he paints a vivid picture of what our future could be like with catastrophic climate change.

I know that most communications people will tell me that we can’t be too doom and gloom, that we have to keep the really ugly truth of what we’re doing to our atmosphere and planet under wraps because people will be frozen with fear and overwhelmed by the problem. Some days I agree with them, but on other days I think it’s really important to look down the long term road to remind ourselves why it’s so important to act on climate change now.

Dr. Ward is an expert in mass extinctions. He has spent much of his career looking at Ammonite fossils to see where in the fossil record mass extinctions occurred and why. Through his studies, he’s discovered that many mass extinctions were greenhouse extinctions.

So what does greenhouse extinction look like? It looks like this:

Buse Lake, Barnhartvale, BC (photo: Norm Dougan)

See the water? It’s purple. It’s purple because there is no longer any oxygen in the water in this lake near Kamloops BC. The bacteria in this lake ‘eat’ hydrogen sulphide, which smells like rotten eggs and allows the bacteria to take over when there is no oxygen in the water. No animals can live in this water – we need oxygen to survive.

So what does a lake in BC have to do with climate change? Climate change caused by human pollution is creating a warmer world and a warmer world means a world with less oxygenated water. I think Dr. Ward put it best in this description of what the earth would have looked like at the end of the Triassic period (p. 138, metric conversions mine):

‘No wind in the 120-degree [48.8c] morning heat, and no trees for shade. There is some vegetation, but it is low, stunted, parched. Of other life, there seems little. A scorpion, a spider, winged flies, and among the roots of the desert vegetation we see the burrows of some sort of small animals – the first mammals, perhaps. The largest creatures anywhere in the landscape are slim, bipedal dinosaurs, of a man’s height at most, but they are almost vanishingly rare, and scrawny, obviously starving. The land is a desert in its heat and aridity, but a duneless desert, for there is no wind to build the iconic structure of our Sarahas and Kalaharis. The land is hot barrenness.

Yet as sepulchral as the land is, it is the sea itself that is most frightening. Waves slowly lap on the quiet shore, slow-motion waves with the consistency of gelatine. Most of the shoreline is encrusted with rotting organic matter, silk-like swaths of bacterial slick now putrefying under the blazing sun, while in the nearby shallows mounds of similar mats can be seen growing up toward the sea’s surface; they are stromatolites. When animals finally appeared, the stromatolites largely disappeared, eaten out of existence by the new, multiplying, and mobile herbivores. But now these bacterial mats are back, outgrowing the few animal mouths that might still graze on them.

Finally we look out on the surface of the great sea itself, and as far as the eye can see there is a mirrored flatness, an ocean without whitecaps. Yet that is not the biggest surprise. From shore to the horizon, there is but an unending purple colour – a vast, flat, oily purple, not looking at all like water, not looking anything of our world. No fish break its surface, no birds or any other kind of flying creatures dip down looking for food. The purple colour comes from vast concentrations of floating bacteria, for the oceans of Earth have all become covered with a hundred-foot-thick [30m] veneer of purple and green bacterial soup.

At last there is motion on the sea, yet it is not life, but anti-life. Not far from the fetid shore, a large bubble of gas belches from the viscous, oil slick-like surface, and then several more of varying sizes bubble up and noisily pop. The gas emanating from the bubbles is not air, or even methane, the gas that bubbles up from the bottom of swamps – it is hydrogen sulphide, produced by green sulphur bacteria growing amid their purple cousins. There is one final surprise. We look upward, to the sky. High, vastly high overhead there are thin clouds, clouds existing at an altitude far in excess of the highest clouds found on our Earth. They exist in a place that changes the very colour of the sky itself: We are under a pale green sky, and it has the smell of death and poison. We have gone to the Nevada of 200 million years ago only to arrive under the transparent atmospheric glass of a greenhouse extinction event, and it is poison, heat, and mass extinction that are found in this greenhouse.’

Are you terrified now? Because this is what our future with runaway climate change could look like. The past that he describes could be the future we are unwittingly creating. The planet will be fine – the planet has gone through this before. But the humans might not be.