| HALF-EARTH Our Planet's Fight for Life Edward O. Wilson New York: Liveright Publishing Corp., March 2016 |
Rating: 5.0 High |
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| ISBN-13 978-1-63149-082-8 | ||||
| ISBN-10 1-63149-082-6 | 259pp. | HC/BWI | $25.95 | |
Dr. Wilson's latest book is the third of a trilogy comprising The Social Conquest of Earth and The Meaning of Human Existence. It contains his thoughts on humanity's overweening activities and the resulting diminishment of the planet's biodiversity — a biodiversity upon which humans rely far more than most of them understand.
Yet that biodiversity is everywhere under attack by humans. The attacks are for the most part inadvertent, to be sure; but there is no excuse for any adult to be unaware of what is happening. Scientists have studied the world too long and too thoroughly. Their findings have been published in textbooks, taught in schools, broadcast on the evening news. Very little of what they have learned is new, and what they have learned includes:
The filtration provided by wetlands and other benefits of nature come under the heading of "ecosystem services." If they were priced according to the equivalent benefits provided by technological means, they would add up to trillions of dollars in costs. In short, not only esthetic aspects of life such as tourism and the enjoyment of wildlife, but day-to-day prosperity and even long-term human survival depend on the web of non-human creatures that surround us, many of which we have not even identified.
Preserving biodiversity does not mean we must immediately stop using motorized vehicles, give up our computers and televisions, and live in huts or caves. It does require us to set aside more land than the current 10% to 20% (depending on the country) devoted to parks or wildlife sanctuaries. Hence the book's title. Setting aside half of Earth's land for wildlife would be no great sacrifice; most of us live in cities today, and more people move to cities every year. It will require a change in our thinking, and some rerouting of highways and railway lines.
I wish Dr. Wilson had spent more of the book on his ideas of how preserving half of Earth's land surface as wildland might be accomplished.
But I digress. Habitat loss is the primary cause of extinctions. Therefore, ecological survival will require reserving some tracts of land connecting our present wildlife refuges: national parks and the like.
"During the past one hundred years, human modification of rivers, streams, and lakes in North America alone (mostly through damming and pollution) has caused the extinction of at least sixty freshwater fish species. Our environmental domination of the land and sea has reduced Earth's biodiversity through the extinction of at least 10 percent of its plant and animal species, mostly in the last century. It is driving species at an accelerating rate through conservation biology's descending categories of "threatened," "endangered," critically endangered," and, finally, "extinct." If this perception seems overstated, consider one of the soundest principles of ecology: the number of plant and animal species sustainable in a habitat increases with the area of that habitat (or decreases with the loss of it) by roughly the fourth power of the area. When, for example, the habitat is reduced in area by 90 percent, the sustainable number of its species is cut in half." – Pages 125-6 |
Dr. Wilson proposes a sort of box roughly paralleling the borders of the United States. Of course, this would require interstate and international agreements for full effectiveness. Some progress has been made; he notes that Florida is assembling a corridor from the Everglades north to the Okefenokee National Wildlife Refuge in Georgia. He also mentions the Yellowstone to Yukon Conservation Initiative, which aims at a continuous path from Yellowstone National Park to Canada's Yukon Territory.2
Dr. Wilson does a good job of explaining why preserving such contiguous tracts of wilderness matters for both practical and ethical reasons. In short, they are vital to our long-term survival.
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