Energy in Nature and Society: General Energetics of Complex Systems , VaclavSmil , MIT Press, Cambridge, MA, 2008. $75.00, $32.00 paper (480 pp.). ISBN 978-0-262-19565-2, ISBN 978-0-262-69356-1 paper

Vaclav Smil’s Energy in Nature and Society: General Energetics of Complex Systems reads like an encyclopedic narrative on energy. With its myriad of facts and figures, it complements the more conceptual approach of Sustainable Energy: Choosing Among Options (MIT Press, 2005), by Jefferson Tester and colleagues; the somewhat more mathematically detailed Advanced Energy Systems (Taylor & Francis, 1998), edited by Nikolai Khartchenko; and the still useful Renewable Energy Resources, by John Twidell and Tony Weir, now in its second edition (Taylor & Francis, 2005). Still, Smil’s book is a must-have for anyone who has an adequate high-school math and science background and has a serious, broad interest in energy systems.

A taste of the style and scope of the book can be found in the variety of questions the author presents: What is the earliest date man is known to have controlled fire? Answer: 900 000 years ago. How much volcanic material was ejected in the formation of the Toba caldera in Sumatra 75 000 years ago? Answer: 2500 km3, over a thousandfold more than from Mount St. Helens in 1980. And how many people were left alive on Earth afterward? Answer: less than 10 000. What are the maximum numbers of people per square kilometer supportable by foraging, pastoralism, slash-and-burn agriculture, pre-industrial permanent cropping, and contemporary agriculture? Answer: 1, 3, fewer than 100, 1000, and 2000, respectively. What are chernozems, whose loss by 1900 accounted for about a quarter of the 1100 billion metric tons of carbon in preagricultural phytomass? Answer: deep and fertile soils. How many thousands of water wheels were used in England in 1086, 1300, and 1850? Answer: 6000, 12 000, and 30 000, respectively. The train of such facts and estimates goes on and on; many of them are fascinating, but they are difficult to take in without frequent pauses in reading.

Smil is a distinguished professor in the department of environment and geography at the University of Manitoba in Canada. With suitable caveats, he makes some attempt to fathom the implications of all his facts and figures for the inevitable transition away from fossil fuels. One telling insight is that increasing energy-use efficiency may well lead to an increase in energy use. The logic, backed up by historical data on steam engines, for example, is that increasing the energy efficiency of a device can lower costs and increase the scope of its use. Smil also has a sensible perspective on the limitations of hydrogen as a transportation energy source in the 21st century, and he does not believe biomass can provide most of the world’s commercial energy unless radical, and as yet, unpredictable developments are made in bio-engineering. He presents data on the remarkable growth in carbon emissions from developing countries, particularly from coal use in China. He notes that the divergence of approach between developing and developed countries suggests that the world is unlikely to achieve effective limits on atmospheric carbon dioxide concentrations within the next one or two generations.

An interesting exception to Smil’s encyclopedic coverage of energy systems is the short shrift he gives to geothermal heating and cooling, despite the noted importance of energy-use efficiency in new construction for burgeoning urban populations. Also missing is a quantitative estimate of the energy or financial cost of long-term management of spent nuclear fuel. As a result, Smil appears unnecessarily skeptical of a transition at some point from dependence on fossil fuels to reliance on the type of nuclear reactors, currently in widespread use, that do not require spent-fuel reprocessing. According to quantitative studies summarized in a 2005 doctoral thesis by T. S. Gopi Rethinaraj at the University of Illinois at Urbana-Champaign, that transition could be accomplished with current technology for nuclear reactors and other non-fossil-fuel energy sources. If successful, humankind will eventually have to confront the question of what to do about the depletion of terrestrial and ocean-based uranium resources. But problems associated with uranium depletion seem likely to be deferred so far into the future that current-day researchers can’t possibly know how to project their effects on demographics and energy use. Many other future scenarios are possible, and Energy in Nature and Society provides food for thought about what those possibilities are.