The World According to Pimm by Stuart Pimm, McGraw-Hill, $24.95, ISBN
0071374906
I READ Stuart Pimm鈥檚 book on the way back from northern Nigeria. Less and
less rain falls here, and it has a fast-rising population and a hopeless and
venal government. Yet the evidence suggests rising farm productivity and a
generally well-fed population. There鈥檚 little sign of the dreaded
desertification.
Pimm believes in desertification, however, and his chapter on it resorts to
one of the UN鈥檚 dodgier datasets, reporting that 鈥渁gricultural practices destroy
about 20,000 square kilometres of rain-fed crop land each year鈥�. Of Africa鈥檚
arid areas he says simply: 鈥淎s the population grows, the land degenerates.鈥�
Well, often not, actually.
Advertisement
The title of Pimm鈥檚 book suggests a new take on the world. The World
According to Pimm, however, pitches the view that humans are mucking up the
planet鈥攁 well-written popular account of this to be sure, but hardly a new
take. He says his favourite newspaper is The Economist. It shows in his
light but didactic style. The sentences are short and to the point. There is
little stuffiness. He takes a pleasure in debunking. But his targets are, rather
like those of his favourite read, often limited and unoriginal. He is hardly the
first to point out that a lot of UN statistics have an unclear provenance.
Pimm鈥檚 main purpose is to quantify key interactions between humans and the
natural world鈥攈is subtitle is 鈥淎 scientist audits the Earth鈥�. He tallies
it all up, from the volume of water we tap to the amount of plant matter we
consume and the number of species we consign to extinction. At the end you can
draw up a balance sheet of sorts.
A professor of ecology at Columbia University, New York, Pimm is excellent at
showing how scientists frame questions and how they try to answer them. But he
himself fails to frame and answer sufficiently interesting questions.
In particular, Pimm is stuck in the world view that believes there is a
natural landscape. Implicit in this is the idea that what was almost untouched
by hundreds of generations of humans is being systematically destroyed by this
one and its predecessors.
Of course, nothing has ever been pristine, and the destruction of 鈥渢he
natural world鈥� is neither total nor inevitable. You would not know it from this
book, but there are probably no virgin forests in the world, and haven鈥檛 been
for many centuries. You wouldn鈥檛 find out that conventional ideas about human
causes of desertification have been stood on their head in the past decade.
So would Pimm debunk my optimism or point out what might be going right? He
notes that, despite all his talk of desertification, there has been 鈥渘o
systematic change in the position of the [Sahara鈥檚] southern 鈥榮horeline鈥� from
1980 to 1997.鈥� There is 鈥渁 paradox鈥� in the evidence, he says. Sadly he fails to
address, let alone resolve, it.
The 鈥渘atural world鈥� view was once useful in highlighting the scale and pace
of ecological damage. Now we are entitled to something more
sophisticated鈥攕omething that takes account of the fact that while we do
destroy, we also create. Something that notes recovery: many parts of the world
have been deforested by humans several times, with the forests regrowing each
time. We are capable, when we do it right, of intensive farming in unpromising
terrain without creating deserts.
We are being forced, painfully at times, to become planetary managers. Pimm
knows this in practice: one of his day jobs is designing ecological restoration
projects for areas like the Florida Everglades. But somehow his 鈥渁udit鈥� is stuck
in a straitjacket of antique bookkeeping.