'Half-earth: our planet's fight for life' reviewed by Arthur Westing
The earth is comprised of the lithosphere, hydrosphere, and atmosphere. With continuing input of energy from the sun, those three great spheres combine to support myriad humans and other animals of all stripes, plants large and small, as well as fungi, bacteria, and various further odd categories of living things — all of those living organisms together comprising a fourth great sphere: the biosphere.
It is the integrity of the biosphere that distresses the renowned author of this anguished plea to save what remains of the living organisms with which we perforce share the earth. The primary insults to the biosphere, as I see it, result in essence from the ramifications of two inexorably worsening factors: (one) the ever increasing numbers of humans — numbers that finally surpassed the carrying capacity for us all to live comfortably within the earth's means some 80 or so years ago; and (two) the ever increasing amounts of carbon dioxide and other so-called greenhouse gases warming the earth to the detriment of the biosphere — amounts that finally exceeded the earth's ability to neutralize them some 50 or so years ago.
Wilson's text — his final one in a trilogy on this general theme — consists of the usual scholarly prolegomena and addenda, with 21 brief chapters sandwiched between them, each led by an apropos 17th to 19th century wildlife woodcut. The 21 chapters are grouped into three parts: (one) "The Problem", with nine largely heartbreaking chapters; (two) "The Real Living World", with seven chapters, in essence providing a primer on natural history, ecology, and conservation (and in the process also repeatedly laying to rest misguided approaches to those areas) — chapters that are enhanced by Wilson's intimately described love affair with nature; and (three) "The Solution", with five aspirational and hortatory chapters (of which very, very few pages are actually devoted to "the solution").
Plant and animal extinctions from natural causes do, of course, continue to occur at a modest rate, but the numbers of extinctions have been increasing dramatically in recent decades, indeed, by many hundred-fold. Various ecologists have estimated that at least 25 percent and perhaps as much as 75 percent of the earth must be set aside for nature to prevent further anthropogenic (human-caused) extinctions. By contrast, the nations of the world in 2010 finally agreed to strive to set aside 17 percent of the lithosphere and 10 percent of the hydrosphere (modestly up from claimed amounts of 15 percent and 3 percent today). It is thus Wilson's hope that before it is too late we humans will at minimum set aside in perpetuity 50 percent of the earth for nature (with the protected tracts connected as often as possible by protected corridors).
What is the scientific basis of Wilson's 50 percent value? Robert MacArthur [incidentally, related to our local Marlboro MacArthurs] together with Wilson had carried out some elegant field studies of birds on isolated Pacific islands, discovering a tight relationship between the size of an island and the number of different species it supported. The same was assumed to hold for the other vertebrate species, and likely beyond. Thus, with today's claimed 15 percent of the biosphere already set aside for nature — if, in fact, that amount does not include too many so-called "paper parks" — about 38 percent of all species are doomed to extinction. If the globally agreed goal of 17 percent will
soon be set aside, then somewhat fewer species would be doomed, About 20 percent of Vermont is now protected.
On the other hand, if human arrogation of the earth's surface could be curtailed within a reasonable time frame in order to achieve Wilson's dream of 50 percent to be set aside for nature, then only about 16 percent of all species would presumably go extinct.
Although still a truly sad state of affairs — given human needs, demands, and desires — Wilson at least considers that level of protection to be both a necessary and an achievable goal.
I am in full sympathy with Wilson's sentiment that "the biosphere does not belong to us; we belong to it." I am also very much with him on the need for "a fundamental shift in moral reasoning concerning our relation to the living environment." And I unfortunately also agree with him fully that "we are fast approaching the point of no return." I therefore wish heart and soul that Wilson's so cogently and movingly described dilemma can, in fact, be reversed. But the oddly limited number of pages he devotes to the solution — suggesting in essence that we have to start caring and then to act accordingly — are sadly inadequate. However, the book is fully approachable for scientists, undergraduate biology students, and the educated laity. Thus, if widely read throughout the "civilized" world, the great length and poignant clarity with which it presents the problem might conceivably provide the necessary impetus for tackling it successfully.
But in fact, I give not a modicum of chance for "our planet's fight for life" to succeed for at least six reasons: (one) our ever greater human numbers with their even more rapid arrogation of the global resources; (two) our continually increasing production of debilitating air, water, and soil pollution; (three) our relentless global warming with its ever greater environmental degradation and resulting species losses; (four) our semi-anarchic community of nations, ineffectual in the face of problems requiring the concerted worldwide cooperation of nations (and also punctuated since the beginning of time by the disruptions of continuous warfare); (five) our misplaced faith in techno-fixes; and, above all, (six) our widespread indifference, shortsightedness, and overpowering anthropocentrism.
Arthur H. Westing is a resident of Putney. He reviews books for the Brattleboro Reformer.
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