Books on environmental doom sell. Remember the bleakness incubated by our environmental wantonness as
foretold in "Limits to Growth"? Thirty years later, most of those environmental chimeras haven't hatched. This
doesn't prove that environmental; disregard is a red herring. The environment, like the Giant Panda, struggles
under increasing pressure. Our population has almost doubled since "Limits to Growth" was published. As our
population grows, it is worth asking from where will the food, fuel and fibre come to feed, warm and house us
all?
"Pillars of Sand", by Sandra Postel in 1999, examines a chink in our armour, the viability of irrigation. Postel is a
Director of the Global Water Policy Project and a past Vice President for a respected, environmental research
organization. She has lectured at major American universities, she was on faculty at Tufts University and she
has served on environmental policy committees for the USA, the UN and the World Bank. Postel's book is
well-researched. It could have been tedious and over-technical, but she has successfully written for a general
audience.
Postel reviews the use of irrigation as an essential tool that allowed civilizations throughout history to expand
and diversify. Irrigation lets fewer people produce more food, more reliably. It has concurrently protected land
from flood and drought. Civilizations in every continent have benefitted from the miracle of irrigation. However,
irrigation changes river flows, causes soil salination, contaminates surface water and destroys wildlife habitat.
Poorly conceived, hastily implemented irrigation projects too often are fronts for sleazy pork barrelling. Some
current irrigation mega-projects reflect egotistical excess with costs greatly exceeding benefits. How do we
separate the disreputably disastrous from the bountifully beneficial?
Postel says, "History tells us that most irrigation-based societies fail. The quest for greater fertility and
productivity can lead to infertility and decline if pursued too vigorously, in the wrong places, or in ways that defy
basic ecological principles. Unfortunately, forty percent of our food comes from irrigated lands. Ten percent of
the world's annual grain harvest is produced on land irrigated by groundwater that is pumped out of reservoirs
faster than nature recharges the reservoirs." We're taking food from our children. Moreover, a thousand tons of
water can produce one ton of grain worth $200 or industrial products worth $10,000 - $20,000. There is
incentive to put water to work where it pays the greatest dividends even if some are left parched.
Postel's book isn't a sensational list of upsetting scenarios, but an objective analysis of historic and current
trends and an extrapolation of what the future may hold. More importantly, Postel, offers tools that we will need
to navigate safely through future shoals and whirlpools. She describes smarter policies and better
technologies. She gives examples of jurisdictions that have, to their advantage, implemented progressive
water management policies and employed water efficient technologies. She writes, "Making irrigated
agriculture both productive and sustainable is part of the larger challenge of restoring balance between the
demands of the human population and the biological requirements of Earth's living systems. Humanity now
appropriates for its own use more than half of Earth's accessible, renewable, fresh water ... this degree of
human dominance leaves a dangerously thin margin of support for the millions of other species with which we
share the planet - species that perform the vital work of nature upon which our societies rest".
It's hard to accept that subordinating individual interests for the sake of collective gains can make us richer and
stronger. But, this is the type of change in values needed more than advanced technology that will lead us to
sustainable cultures. There is still hope for the prepared and the flexible.