I fly window seat, incurably. It doesn't matter that I've been on countless flights over the past four decades and stared downward over numberless vistas of forest and wetland, prairie and river. When the flight attendants ask for people to lower the window shade so that you can see the movie better, that's my shade still up, my face pressed against the glass.
I revel in the details of geography and sweep of biology that can be seen from the air. I trace trails into box canyons and along mountain ridges; search tundra for oriented lakes; look at sediment roiling downcoast from a turbulent river mouth; scan bayous for cypress islands; enjoy the dendritic meanderings of channels through a tide flat; discover oxbow lakes along the fringes of a river basin.
Anyone who shares this affliction with me knows, however, that what one sees most of the time along too many common routes is the human footprint: dams and dikes, farmland, shopping malls and roads, hills bulldozed, forests flattened, massive works of civil (and uncivil) engineering.
The ubiquity of this footprint makes me think of Goldfinger. Bond's villain, you may remember, had a particularly twisted way of disposing of one of his enemies: he covered her entirely with gold paint. Up to a point, his victim could survive, but cover enough and her skin would no longer be able to breathe. However mythical might have been Goldfinger's technique, the image of that gilded body comes to mind when viewing the earth from the sky and seeing what a remarkable percentage of its surface has been churned or covered by human toil.
Metaphors leap from odd places (perhaps the strangest come from staring out of one too many airplane windows), but they can pose important questions. How much of the earth's ecological integrity can we disrupt before we pass a threshold in the loss of life-support services provided by natural ecosystems? Issues of ecosystem services-what they are, what they contribute to life on earth, their role in building and maintaining human prosperity, their vulnerability to disruption and the impact of their losses-are central questions for modern science. Or rather they should be, given the expanding scale of human impact upon the landscape.
That is why the work contained within this volume is so important. Its interdisciplinary, synthetic overview of the nature and value of ecosystem services reveals four things simultaneously. First, that we know enough now to understand in broad brush that ecosystem services are essential for human life as we live it today and as we would hope our children live it in the twenty-first century. These services are myriad. They include provision of clean water and flood control, creation of soil, pollination of crops, providing habitats for fisheries, and countless other benefits that underpin human well-being.
Second, the analyses presented herein show that for engineering to replace the services that ecosystems now provide is-if not completely beyond current technology-prohibitively expensive if implemented at anything but a trivial scale. Third, they make clear that our scientific and economic understanding of the true dimensions and details of these services is appallingly shallow.
Fourth-and with the greatest direct relevance for today's public debates about environmental protection-the combination of ignorance and import revealed dictate caution. We do not know where we are in Goldfinger's attack... how far we are today along the functions describing service output in relation to ecosystem disruption, nor the incremental effects accruing from each new degradation.
I am reminded of Wendell Berry in Home Economics (1987): "Acting on the basis of ignorance, paradoxically, requires one to know things, remember thingsfor instance, that failure is possible, that error is possible, that second chances are desirable (so dont risk everything on the first chance) ." The contents of this book teach that for ecosystem services we need more than a second chance. We need a serious, unwavering commitment to science and policy that will ensure that the life-support processes flowing from natural ecosystems continue undiminished.