Climate Process and Change

  • Edward Bryant
Cambridge University Press: 1997. Pp.209£45, $59.95, (hbk); £16.95, $22.95 (pbk)

The science of Earth's climate system has gone from being the preoccupation of a handful of pioneers to a large international research effort. Its unique complexity means that only the combination of high-quality research across disciplinary boundaries will generate the innovative results needed for progress. So a book intended for use in undergraduate courses is timely.

In Climate Process and Change, Edward Bryant seeks to present in simple terms the workings of the climate system and its changes. He does so in three parts, on processes, change and impact, in just over 200 pages, too few for in-depth discussion. Readers would appreciate references to more specialized sources or excellent textbooks such as Physics of Climate by J. P. Peixoto and A. H. Oort (American Institute of Physics, 1992) or Paleoclimatology by T. J. Crowley and G. R. North (Oxford University Press, 1991).

More than half the book focuses on the past century, and the question of global warming is a recurring theme, presented here in a rather one-sided manner. Students reading this text would end up with the “acquired bias from previous instruction” that Bryant sets out to correct.

Central to our understanding of climate processes are the natural sciences, whose language is equations. This book contains very little — and often sloppy — physics, and the few equations are hardly useful; for example, y = bxn (where n ≠ 1) is explained by “Many climatic processes behave like this and have a value of n between 1.0 and 2.0”.

A chapter on the transport of heat and matter introduces the reader to large-scale meridional air flow — the concept of transient eddies is not mentioned — and to urban climate and “mobile polar highs”. We learn that this concept, unknown to dynamical meteorologists, explains the atmospheric circulation for the climatic states of the glacial, today and in the future. A narrow and often incorrect view of ocean circulation and processes follows.

In the discussion of Pleistocene change, there is no metion of the rapidly accumulating results from various novel proxy indicators extracted from marine sediments, corals and tree rings. There is a fairly complete account of the causes of climate change but stating that it is impossible to attribute temperature change during the past century to different causes ignores recent promising advances in statistical analysis.

The book closes with two interesting chapters on the impact of climate change on health and ecosystems. I am happy to learn that climate-related diseases “may not be the biggest threat to human health” and that food contamination at a “fast-food outlet or wedding reception” may be more dangerous.

In his epilogue Bryant says that “if greenhouse warming is a reality, then its arrival may well be timely, because it has the potential to compensate for the strong cooling that may be a natural part of the ocean-atmosphere system, under the heavy atmospheric dust and sulphate aerosol loadings presently being stimulated by human activity”. I prefer his alternative view, earlier in the book: “as with all human tampering with climate, there are bound to be negative ramifications”.