What We Know about Climate Change

Kerry Emanuel is one of the world's foremost experts on hurricanes, a professor of atmospheric science in the Department of Earth, Atmospheric, and Planetary Sciences at MIT. In this *excellent* little book he describes the basics of our scientific knowledge in the area of climate change, without succumbing to the temptation of presenting a heated polemic that so often accompanies this topic. Rather, he straightforwardly describes the science -- noting its complexity and not under- or over-stating its uncertainties. What's left is a truly informative look at the current state of our understanding and the firm belief that continued study will refine our knowledge.

Every person should read this short book to see how complicated and interlaced the earth's weather system is. Then you can decide for yourself if we can change it either way.

Emanuel has written an outstanding survey of the difficulty and methodology of doing climate change science. One comes away convinced that something needs to be done, although Emanuel doesn't prescribe solutions. The afterward, by Judith A. Layzer and William R. Moomaw, is a pallid letdown after the concise and perceptive work of Emanuel. The backgrounds of Layzer and Moomaw are omitted, unforgivable in the context of the discussion. (Layzer is is Associate Professor of Environmental Policy in the Department of Urban Studies and Planning at MIT and Moomaw is Professor of International Environmental Policy and Director of the Center for International Environment and Resource Policy at Tufts). They are guilty of the academic bias that Emanuel talks of and contribute nothing to the issue. What a shame to sully an otherwise useful book with such irrelevance! Five stars for Emanuel's work. One star, at best, for the afterward. I worked as an experimental physicist before retirement and have been appalled by the lack of scientific acumen exhibited by politicians, the public, and some of the scientific community. I'll give this book to friends with a disclaimer about the afterward.

Dr. Emanuel does a superb job of separating the wheat from the chaff in this little gem. It's virtually impossible for the average layman to separate conspiracy theory nonsense from fear-mongering reading most books and popular press articles on global warming. But Emanuel presents a sound authoritative analysis of what we really do and don't know. Unlike many other books on global warming, which bury the reader with a plethora of out-of-context quotes, tables of data, and cherry-picked charts, Emanuel presents just enough solid data for the reader to understand the whole issue. He covers the philosophic underpinnings of different views, the history of global warming, the science, and finally the politics. When put together in this fashion, readers will educate themselves properly. Before reading this book, I spent months and months reading peer reviewed scientific journal articles, web-site after web-site, and many popular press articles. Had I read Dr. Emanuel's book sooner I could have obtained the same final position with much less work and time invested.

Be forewarned this is a very small book: 82 pages of text, one B & W figure and no references. On a typical page I counted 120 words. I spotted no typos. I found only one sentence where I thought the physical explanation was muddled. The text could provide an excellent narration to a video documentary. A typical citizen needing to get wise about the physics of global warming might be better served by something more than a book without graphics. Nevertheless, the book is a very quick read and professionals in this field may still enjoy scouring the pages of this book to find out where Professor Emanuel stands on certain issues. I got my money's worth on page 67 where we can read: "Scientists are most effective when they provide sound, impartial advice, but their reputation for impartiality is severely compromised by the shocking lack of political diversity among American academics, who suffer from the kind of group-think that develops in cloistered cultures. Until this profound and well-documented intellectual homogeneity changes, scientists will be suspected of constituting a leftist think tank." 15 of the 82 pages are not Prof. Emanuel's words, but is an "Afterword" provided by other authors. These words carry less authority. For example, the Afterword attributes the melting of the snows of Kilimanjaro to global warming, but some recent scientific research implicates land use changes around Kilimanjaro. The Afterword also lays out a plan to save us from global warming, with a claim that "addressing global warming could be relatively painless". Here is the plan: "the United States and other industrial economies reduce their emissions by three percent per year between now and mid-century" which will ultimately "reduce global emissions by 75 percent or more". Some of the means to do this provide a chuckle: "driving less aggressively". No account is made for global population growth and global ambitions for prosperity.