environmental and ecological science who need a basicunderstanding of chemistry.

The book begins with a description of some fundamentalconcepts concerning atoms and atomic structure, chemicalbonding and the properties of matter. The basic buildingblocks of physical chemistry then follow, includingmaterial on chemical kinetics, photochemistry, chemicalequilibria, electrochemistry and the chemistry of surfacesand colloids. Chapter 3 contains the chemistry of theelements, expanded somewhat in this third edition. Thetechniques of environmental analytical chemistry arecovered in chapter 4 with some excellent illustrations ofpractical relevance to the environmental sciences.Environmental biogeochemistry is covered in chapter 5,with particular attention being given to the global green-house effect and the build-up of persistant organicpollutants in the global environment. The ®nal chapterworks through a number of case studies dealing withspeci®c environmental problems in the ®elds of atmo-spheric chemistry, freshwaters, sea waters, soils and marinesediments.

R. G. DERWENT

Meteorological Of®ce, Bracknell

INTERACTIONS OF DESERTIFICATION AND CLIMATE., pre-pared by Martin A. J. Williams and Robert C. Balling Jr. forthe World Meteorological Organisation and the UnitedNations Environmental Programme, Arnold (London),1996. No. of pages: xiv� 270. Price: £50.00. ISBN 0-340-63217-8 (hardback)

Once upon a time, there were text-books to guide theuninformed, and there were accounts of original thoughtand ®rst-hand research. Now there are books, like this one,prepared for international institutions to present a semi-of®cial review of the state of the art in the subjectconcerned. Each may represent a well-funded study. Thetext may have been subjected to peer scrutiny. Referencesmay provide a working basis for future research.Sometimes, however, there is a distinct impression thatpublications counter to the received view are deliberatelyomitted, unless they can be speci®cally refuted. There areother drawbacks. Peer review and collaboration mayoperate against originality. Conclusions may be designedto safeguard future opportunities for the scienti®c commu-nity. Such publications represent a strange aspect ofintellectual culture in the late twentieth-century. Anexecutive summary is de rigueur and one imagines suchbooks presented to politicians at conferences, or availableon the shelves of a tidy of®ce in an internationally fundedorganisation, to show visitors `what we know'. Well donethat man!

How does the present volume fare in this context? Weare told that it is a substantive scienti®c document, acomprehensive report on current knowledge, prepared`under memorandum of understanding', whatever thatmight mean, by UNEP and WMO. To be fair, the authorshave made a useful study of literature on relationships

between land degradation and climate. They have suc-ceeded in conveying the challenge of contradictory view-points and their review will be useful to those needing aworking knowledge of subjects like the in¯uence of albedo,salinisation, soil moisture and plant growth, etc. There isunnecessary repetition. The recommendations are repeated,word for word, at the end of each chapter, in the ExecutiveSummary, and in the ®nal Summary, Conclusions andRecommendations. Other details are inconsistent. In theExecutive Summary, deserti®cation is said to be a directthreat to over 250 million people and an indirect threat to afurther 750 million. According to the Introduction, over 200million people are severely at risk and a further 700 millionless severely affected. There are other statistics galore, buthow, for example, do we know that 54% of rainfedcropland in Europe is deserti®ed (deserti®ed and degradedare taken to be more or less synonomous)? One wonderswhy no reference is made to Thomas and Middleton (1994),who warn against the use of `guesstimates or, at best,estimates' to drum up concern.

The book is divided into ®ve sections: the impactof deserti®cation on climate; the impact of climateon deserti®cation; global climate change and the futureof dryland climate; mitigation and rehabilitation strategiesto combat deserti®cation; summary, conclusions andrecommendations. There is the inevitable review of green-house gases and simulation experiments, with speci®cpredictions for certain areas that need to be `cautiouslyinterpreted'. Map coverage is patchy and derivative, but theauthors can be complimented on a clear text which conveysa reasonable insight into research in progress. Finalrecommendations include the need to adopt uniform criteriaand methods to assess deserti®cation; establish regionaltraining centres to monitor dryland degradation; identifysources and sinks of dryland carbon, aerosols and tracegases; evaluate rehabilitation projects; enhance regionalclimate monitoring networks; couple numerical modellingstudies with ®eld measurements; assess biogeophysicalmodels of Sahelian drought; apply seasonal climateforecasting to dryland management; and provide naturalresource information from Geographical InformationSystems to local communities. One wonders why noreference is made to Tiffen, Mortimore and Gichuki(1994), who make no ambitious claims, but show whatcan be achieved by a local community with just a little helpfrom outside.

REFERENCES

Thomas, D. S. G. and Middleton, N. J. 1994, Deserti®cation:Exploding the Myth, Wiley (Chichester).

Tiffen, M., Mortimore, M. and Gichuki, F. 1994, More people, lesserosion: environmental recovery in Kenya, Wiley (Chichester).

JOAN M. KENWORTHY

University of Durham

CLIMATE CHANGE 1995: THE SCIENCE OF CLIMATE CHANGE.

Contribution of Working Group 1 to the SecondAssessment Report of the Intergovernmental Panel on

904 BOOK REVIEWS

Climate Change. J. T. Houghton, L. G. Meira Filho, B. A.Callendar, N. Harris, A. Kattenberg and K. Maskell (eds).Cambridge University Press (Cambridge) 1996. No. ofpages: xii� 572 pp. Price: £65.00, US$90.00 ISBN 0-521-56433-6 (hardback); £22.95, US$34.95 ISBN 0-521-56436-0 (paperback)

In 1990, Cambridge University Press published `ClimateChange: the IPCC Scienti®c Assessment'. It was a reportfrom a committee jointly established by the WorldMeteorological Organisation and the United NationsEnvironment Programme. Working Group 1 had the taskof assessing available scienti®c information on climatechange. At that time, the Book Review Editor of theInternational Journal of Climatology decided that as thereport by the Working Group could be one of the keyclimatological publications of the decade, two reviewersshould be asked to assess it. The reviews by Professor S.Gregory and Professor R. S. Scorer appear in volume 11(4), p.457±460 (1991).

Such has been the rate of progress in this area of climatechange that within ®ve years another book, with a similarbrief, has appeared. Although it has many similarities interms of its content and method of production, this is anentirely new book. It aims to update information on thesame range of topics as the First Assessment and to becomea standard work of reference, widely used by policymakers,scientists and other experts. Unfortunately, despite thestrong comments made by Professor Scorer in the earlierreview, there is still no index provided. As there are manyinter-linking themes which appear in several of the elevenchapters, it is infuriating to have to search through eachchapter to ®nd all references for any particular topic. Itsabsence might help the speed of publication but it doeslimit its value as a ready source of information. Changesthat have been made include a Summary for Policymakers,which undoubtedly will be used by anyone who has not thetime or knowledge to read through the scienti®c chapters,and a Technical Summary prepared by the lead authorstaking into account comments arising from extensivereview by individual experts, governments and non-governmental organisations. It has also proved possible toincorporate coloured diagrams within the text which is atremendous improvement for the reading and interpretationof the ®gures.

The structure of the work has changed slightly to presenta more comprehensive and logical format. We start with abrief overview of the climate system and the way in whichclimatic models can be prepared to predict changes ofclimate. The nature of radiative forcing in the atmosphereand how it may in¯uence change is examined in chapter 2before observed climate variability and change is describedat an earlier stage than in IPCC 1990. Three successivechapters then consider the processes in the climate systemthat are believed to contribute the most to the uncertaintiesin current projections of greenhouse warming, an evalua-tion of the current models and what these models indicatein terms of future climate. Chapter 7 assesses the current

state of knowledge regarding climate and sea level changeafter which we hear about the problems of detecting climatechange and the attribution of causes. Two further chaptersconsider the terrestrial and marine biotic responses toenvironmental change and their feedbacks to climate. Thebook concludes with a useful review of how scientistsmight progress in improving our understanding aboutclimate change and future research priorities.

This is not a book to be read from cover to cover.Fortunately it has been well designed so that there are thetwo introductory summaries, one for policy makers and atechnical summary together with summaries preceding eachchapter. These form the essential core of the work. Thechapters contain the results of much recent research, oftenin considerable detail and depth. One of the main issuesidenti®ed in this Second Assessment is the role of sulphateaerosols in in¯uencing climate change. Observed andsimulated global mean temperatures over 1861 to 1994are much closer when both greenhouse gases and sulphateaerosols are included within the models. The mystery of thedecline in global mean temperatures between 1940 and1970, which causes problems for the greenhouse gasexplanation, may now have been resolved.

Although this book represents a state of the artdeclaration by a wide range of climatologists andmeteorologists (listed in the various appendices), inevitablythere are scientists who might disagree with the book'sconclusions that human in¯uences are beginning to have animpact on global climate. Where such contentious issuesarise, these have been examined and explored within thetext. However, controversy still follows the subject ofglobal warming and this book is no exception. Itspublication has been criticised on the grounds that it isnot the version that was approved by the contributingscientists listed on the title page. A discussion of theproblem and a rejoinder by key members of the AmericanMeteorological Society has been published in the Bulletinof the American Meteorological Society, volume 787 (9),p.1961±1966 (1996). It makes interesting reading and awarning on how vital issues can easily be side-tracked oncethe media become involved. Nevertheless I am sure thisbook will be a reference book on the subject of climatechange for the next few years. The amount of research onthis theme in the near future will determine how long it willremain before being superseded by a further update.

PETER A. SMITHSON

University of Shef®eld

PROBLEMS OF STABLE ISOTOPES IN TREE-RINGS, LAKE

SEDIMENTS AND PEAT-BOGS AS CLIMATIC EVIDENCE FOR

THE HOLOCENE. Edited by Burkhard Frenzel, Co-edited byBernhard Stauffer and Mirjam M. Weib. Special Issue:Project European Palaeoclimate and Man 10, GustavFischer Verlag, Stuttgart, 1995. No. of pages: xii� 189.Price: DM 78.00 ISBN 3-437-30817-3 U.S. ISBN 1-56081-436-5

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