|DRIVEN TO EXTINCTION
The Impact of Climate Change on Biodiversity
Richard Pearson, Ph.D.
New York: Sterling, March 2011
Richard Pearson is a scientist with the American Museum of Natural History in New York City. As you will see when you read this book, he has (although he doesn't shout the fact) spent much time in the field investigating the questions he discusses here. Those questions are important ones; they concern the long-term viability of the living world we have known. Those investigations, and the collaborations involved, have prepared him to present a cogent and very well organized introduction to the ways that world may be diminished and how we can limit the damage.
As he notes in his Preface, studies have indicated the possibility that as many as one million species may go extinct as the twenty-first century rolls along. Climate change is the demon behind their demise, according to many articles in the popular press, but Pearson shows us that is only part of the story. Nor is he convinced that things will inevitably turn out so badly; much still remains to be learned about the complex ecological interactions between individual species, biomes, and human interventions. Habitat destruction, resource depletion, and the greenhouse gases and other pollutants we produce will have a big impact — but exactly how big we cannot yet pin down. What is clear is that we all of us can adjust the size and scope of that impact by the decisions we make.
"Climate change and nature conservation are—like it or not—issues that are important for all of us. We must be armed with a clear understanding of the risks involved if we, as a society, are to make informed and reasoned decisions about the actions that should be taken to face the challenges of the coming century. My hope is that this book contributes toward deepening that understanding."
– Page vii
My judgement is that Dr. Pearson's book makes a major contribution to understanding these issues. He illuminates the science through jargon-free case studies of individual species and habitats, from Viet Nam's Orange-Necked Partridge to the Banner-Tailed Kangaraoo Rat of the American Southwest, and from Alaskan tundra to coral reefs in the Philippines. His discussion is illustrated by 48 color plates, each one keyed to a specific page of text.
To give you just a hint of the complexities of the problem, I'll mention two findings: First, climate change is implicated in the disappearance of the Golden Toad and other amphibians in South and Central America because it tends to dry out the cloud forests that support them. But, often, those at the middle elevations are hit badly while others higher and lower escape. It turns out a certain fungus needs a narrow range of temperatures which occurs only in those middle heights. Thus, warmer temperatures can be both good and bad for these species. (Chapter 2)
The second illustration comes from the work of ecologist Blake Suttle. He set up experimental plots in the Angelo Coast Range Reserve of California's Mendocino county. His plan was to supplement the natural rainfall and see how biodiversity was affected. You might think it would increase, and so it did for the first two years of Suttle's experiments. But then the trend reversed, and by the fifth year his plots had only half the species diversity of untouched local habitat. The reason is that grasses did so well compared to other plants that they took over and the nutritional value per square foot dropped sharply. (Pages 175-9)
Dr. Pearson also considers the way scientists interact with the media. He acknowledges the pitfalls of scientists engaging in public advocacy of specific policies:
"We tend to expect that the media will sensationalize an issue, and that politicians will speak from the perspective of their party line. But the ideal of science is that it remains objective and independent. Embellishing research with claims that can be criticized as alarmist and exaggerated may not only undermine the public's trust in scientists, but could actually prove counterproductive to conservation efforts. There is a risk that claims perceived as overstated will be met with public cynicism and disbelief—this is just those tree-hugging greenies spreading scare stories—that might, in turn, lead to apathy and inaction with regard to tackling the issue."
– Page 95, emphasis in original
But he concludes that scientists have as much right as any other citizens to speak out on matters that affect them, and given their particular knowledge a duty to make their perspective available to the public — the more so when social conditions tend to impede that, as they do today. He admits that this may verge upon advocacy, and seems uncomfortable with that; but then, does any other interest group refrain from advocating policy? In the final analysis, he reminds us that it is we members of the voting public who must decide which policy to follow.
"We reach the point where you, the reader, armed with a thorough understanding of the issue, must form a personal opinion of what action society should take. Your opinion matters. You have the power to influence society by exercising your democratic right to vote and by spending your money on products and services that are in tune with your values."
– Page 225
In his final chapter, he looks at some of the conservation measures already under way that are designed to cope with the new, global threat to biological diversity: measures like the various seed banks, and the Yellowstone to Yukon Conservation Initiative.
If you want an objective discussion of all facets of the problem, free of confusing technical jargon and distracting polemics, this is a book you should read. In addition to the usual endnotes and index, there are 155 references listed.1 Full marks.