Sunday, December 07, 2008

Under a Green Sky: Global Warming, the Mass Extinctions of the Past, and What They Can Tell Us About Our Future, by Peter D. Ward


To my shame and embarrassment, I hardly ever read books on science or global warming. Only every now and again. And this despite being a committed Greens voter. Science muddles my mind, but slowly I'm becoming more unmuddled.

Canadian author Gwynne Dyer in his most recent book Climate Wars discussed this book, Under A Green Sky, by Peter D. Ward. Basically, it's about the mass extinctions of the past. By past, it's meant hundreds of millions of years ago.

It's been a long held theory that one of the big extinctions of the past (known to science people as the Cretaceous - Tertiary (K-T) boundary) was caused by a big asteroid roughly ten kilometres wide. This and other 'extinction events' caused massive wipe-outs, up to 70% of species.

Science has had two camps on the subject of mass extinctions. One was the aforementioned asteroid theory. The other was extreme and catastrophic climate change. For many years it appeared the asteroid camp had won out. But further research and study has put the climate change camp in the lead.

How is this done? Scientists can measure past atmospheric concentrations of greenhouse gases such as carbon dioxide or methane by analysing isotope ratios in rocks. When I read H. G Wells's Time Machine, I thought this was purely fiction. It seems that you now can travel through time.

This book argues that it was climate change that caused mass extinctions in the past. Hence the book also acts as a cautionary tale by describing the horrific effects that man made climate change could effect in our own time.

Mr Ward writes in a chirpy tone for the non-science reader, so you won't struggle with lots of difficult and obscure language. The chief charm of the book for me was feeling like a time traveller, going back hundreds of millions of years. Humans are so vain. We're only approximately two hundred thousand years old, yet we act like we own the world. Not so. We're just a blip on the earth's radar. No doubt we'll only be here for a short period of time, while the world will roll on.

From Wikipedia: Anatomically modern humans first appear in the fossil record in Africa about 130,000 years ago, although studies of molecular biology give evidence that the approximate time of divergence from the common ancestor of all modern human populations was 200,000 years ago.

Peter Ward's salutary aim with this book is to bolster the argument for reducing our emissions, yet this book made me feel that all of our efforts were inconsequential when confronted with nature. We're like ants trying to stop elephants trampling us to death.

The devolpment of agricuture has created the phenomenan of global warming in our own times, a practice started over 10,000 years ago. Man has always measured his genius against how far he could outfox nature. Yet nature will always have the last laugh at us. Scientists seem intent on humbly trying to read what Shakespeare called the book of nature. How far, if at all, they can see into the future is another question.

From a common sense perspective, despoiling our environment seems like madness. (Remember the recent story about a methane gas leak from a nearbye landfill in new housing estate in Cranbourne?) For that reason alone, cutting emissions and taking care of the environment is clearly a sensible policy.

No comments: