Book reviews by Roy Williams, author of 'God, Actually'

These book reviews written by Roy are published for the first time on this website.

What Is Biodiversity?
By James Maclaurin and Kim Sterelny
The University of Chicago Press, 217pp.

For many citizens in the West, the issue of climate change remains strangely unreal. Almost everyone can grasp its potentially momentous implications in theory, but in practice it still intrudes little upon most day-to-day lives. Ross Garnaut, Australia's climate change guru, has lamented that it is "harder than any other issue of high importance that has come before our polity in living memory".

Why? There are a number of reasons, but it seems to me that one stands out. Most people are innately sceptical of doomsday predictions by scientists. Climate change is different in kind to the spectre of nuclear holocaust: even at the height of the Cold War, ideologues on both sides did not quibble about the destructive power of nuclear weapons. Everyone had seen photos of Hiroshima and Nagasaki and footage of atmospheric tests.

At an intellectual level, the assumption behind the Garnaut Report is absolutely sound: "The outsider to climate science has no rational choice but to accept that, on the balance of probabilities, the mainstream science is right in pointing to high risks from unmitigated climate change." Simply put, there is too much at stake just to hope that the scientists are wrong. Even so, I suspect that most of us do not yet believe - at a "gut" level - that the experts are right.

In one way this is unsurprising. For the best part of a generation throughout the democratic West, political opportunists of all stripes have railed against "elites" in order to curry favour with poorly-educated, low-income voters. "Out-of-touch intellectuals" in "ivory towers" have been routinely demonised. The result is that learning and expertise have been devalued in favour of a vulgarised kind of "common sense".

At the same time, far too many privileged and wealthy people - in government, the financial sector, business, the media, the professions, academia, the military, the churches - have betrayed the trust placed in them, sometimes egregiously so. High-level dishonesty is endemic.

Urgent, far-reaching, and compulsory measures to combat climate change will eventuate in Western countries such as Australia if, and only if, a clear majority of the electorate actively demands them. The world's powers-that-be are now like the boy who cried wolf. They do not enjoy the trust that would allow them unilaterally to impose such measures, assuming they had the guts to try and could agree amongst themselves upon a decisive course of action.

Can the crisis be met? Personally, I don't think so. Speaking as a layman, I doubt that Man has the technological capacity to solve the problems we appear to have set in train. They look to be just too complex and too enormous. And even if effective solutions could be developed in time, I fear we lack the collective maturity to implement them. To do so must surely entail gigantic expense and substantial erosion of First World living standards, at least in the short term.

I am driven to this view: divine intervention aside, the best hope for human civilization is that our scientists really are wrong after all. Furthermore, that possibility may be more likely than it seems.

Morally, though, it would be wicked to rest on our hands. And if there is any chance of Man averting the predicted catastrophe by his own efforts, the key, surely, is public education.

Books such as What Is Biodiversity? could play a significant part. The co-authors, James Maclaurin and Kim Sterelny, are distinguished New Zealand academics. Their book is erudite and scholarly, and is targeted at experts in the field of conservation biology. It is not primarily about climate change. But the authors make a number of points which are highly salient to the climate change debate.

Some terminology is in order. "Biodiversity" is a measure of various features of a geographical region. The best single indicator of biodiversity, albeit a rough one, is so-called species richness. This is a calculation of the total number of different species which live in a region - not only animals, but also fish, birds, insects and plants.

Additional suggested measures of biodiversity include:

Abundance - the size of the population of each of the species in the region (e.g. 20,000 ring-tail possums, 50,000 magpies etc.)
Plasticity - the ability of a given species individually, or of an ecosystem collectively, to adapt to environmental change by Darwinian processes (genetic mutation and natural selection).
Disparity - the degree of differentiation between species in the region, principally assessed by reference to "genealogical proximity" (the age of the common ancestor of any two or more species). Also pertinent are each organism's phenotype (physical appearance) and ecological function (e.g., predator, herbivore, pollinator etc.).

As Maclaurin and Sterenly admit, each of these criteria is not uncontroversial. Even the definition of a true species is not clear-cut. (The famous "reproductive isolation" test is at best a guide: it works better for animals than plants, and even then is not foolproof. "As most of us know," the authors explain wittily, "whether you are in with a chance depends on who else is at the party. New Zealand black stilts (Himantopus novaezelandiae) prefer to mate with members of their own species, but they will mate with pied stilts (Himantopus leucocephalus) if no black stilts are available"!)

Notwithstanding these and other grey areas, Maclaurin and Sterelny make a persuasive case that the study of biodiversity is scientifically and philosophically valuable.

How is all this relevant to climate change?

The authors point out that conservation biology is a "crisis discipline". It aims to find urgent but practical answers to forbidding and complex questions. "One of [biology's] most important projects is to predict and explain change. To put it mildly, this project is not merely of theoretical importance. Climate change is upon us, and if possible we need to anticipate the array of environmental perturbations likely to accompany [it]."

I do not disagree. Even so, bearing in mind Maclaurin and Sterelny's arguments, my conclusions about climate change are fatalistic.

For a start, I was reminded that natural ecosystems are extremely finely-balanced. They are the end-product of eons of evolution, a vast "conspiracy of history, environment, and chance". Moreover, the authors stress, species are interconnected: "Local populations do not live independently of one another. Species depend on the local biology; there can be no echidnas without ants."
Second: "Organisms do not just eat, breed and die. They reorganise their environment." In this sense, Man is not unique but typical. But here's the rub: 99 per cent of the species that have ever lived are now extinct. They failed to adapt to environmental change, including change they wrought themselves. Such change was often far less abrupt and profound than that which now threatens Man as a result of global warming.

Thus, while it is true that life on Earth has survived "mass extinction" events in the past - from asteroid collisions to ice ages - there can be no guarantee that Man as an individual species would survive climate change, still less that life as we know it would continue to flourish.

Third, and most important, Man's ignorance of natural processes is much greater than we like to suppose. Maclaurin and Sterelny make this point repeatedly. Why, for instance, are there no centaurs? We do not know. The "hottest of hot topics" in biology is, apparently, "developmental modularity" - the mind-boggling theory that certain traits of individual organisms somehow evolve independently of other traits. "Genetically caused modification in one system need not wait for genetically caused change in associated systems, even when both organ systems must change for either change to be adaptive." (my emphasis)

For experts in the field of conservation biology, perhaps the most fundamental question is this: Which species are worth conserving? Maclaurin and Sterelny reject an "equivalence principle", but acknowledge that there is fierce debate as to the criteria against which "worth" should be assessed.

That (major) controversy aside, there is an overriding problem. Man still does not know enough about the mechanisms of evolution to make irrevocable decisions affecting the planet's biological future - at least, not ones which can credibly be regarded as safe. There has arisen a notion of "option-value". The nub of it is that all species are prima facie worth preserving because Man cannot know for certain if, or when, or why, an apparently "expendable" species may become valuable in the future.

A closely-related idea is that Man cannot presently be sure whether the extinction of a given species today will trigger a widespread environmental upheaval. Maclaurin and Sterelny invoke the analogy of popping rivets out of an aeroplane in flight: "Initially this activity has little effect. But at some crucial point the results are calamitous; a wing falls off."

It follows from all this that climate change denialists merit little credence. Any suggestion that we can ignore any and all concerns about man-made global warming with reasoned confidence - i.e., based on what we actually know - seems to me not just reckless, but positively absurd.

That said, Man's very ignorance could be our best hope. The sincere and near-unanimous views of the world's most eminent climate change scientists cannot, and should not, be ignored. Yet I cannot shake a feeling they might well be mistaken, and that Nature - and God - have many more surprises in store.

Bonus Book Reviews by Roy Williams