In principle, a book on the intrinsic relation between the progress of human civilization and energy development is nothing new. The author, Vaclav Smil – Distinguished Professor Emeritus at the University of Manitoba, Fellow of the Royal Society of Canada and Member of the Order of Canada-, already wrote one in 1993. The very first edition was, in fact, Energy in World History: with time passing by, despite the numerous follow-ups, it became clear that a new remaking was needed.
The output of Energy and Civilization: a history  is a fascinating analysis that illustrates how human history is deeply connected to the ability to transform, store or use multiple forms of energy over time. In fact, Smil interprets evolution of complex societies as improvements in the capacity to manage increasing flows of energy from higher quality sources as well as to enhance energy use efficiency. These concepts, essential to understand the entire book, are briefly introduced in chapter one. The remaining part of the book can be instead divided in two macro-topics: how energy production and use evolved over time and the feedback loop between the increasing complexities of societies and the adoption of new technologies (an important take away is that an innovation is nothing without the right incentives to adopt it).
From chapter 2 to 4 is addressed long path from the very first period human existence to the full development of traditional agriculture (3.5 million of years ago up to 1800). For example, it rationalizes the choice of the standing posture as a more efficient solution – bipedalism requires 75% of the metabolic expenses required by quadrupedal walking. Additionally, it allows for a better access to food. The quality of food consumed was, in turn, essential for a higher encephalization quotient – critical for the rise of social complexity. It was the need of primitive societies to satisfy their energy imperatives that created the constant feedback loop between energy, population growth and development.
Chapter 4 and 5 instead addressed the outbreak of other sources of power other than farmers’ muscles. The application of new technologies enabled to transform the kinetic energy (namely wind and water) into labour mainly through the spreading of mills for producing work and sails for transportation. The human capital freed up from field work and the exceed food production with respect to the basic demand of the society, were then diverged to other activities not directly connected to agriculture contributing to increase the complexity of the societies. Nevertheless, it took a long time before the new inventions allowed a significant improvement in life quality of a large share of the population. Those improvements were truly perceived, with uneven distribution, only with the beginning of era of fossil fuels (chapter 5) which brought a significant reduction in food and energy prices. However, those also amplified the impact that humans have on the environment: wide is the discussion on timber demand of the Roman empire (750 hectares of forest per year for copper smelting at Rio Tinto) versus the hypothetic need of the U.S. for iron smelting in 1910 if coke and other wood substitutes would have not been in use (180,000 km2 per year). Unfortunately, the discussion on renewals adoption has not been as deep (neither was, to me, the discussion on carbon emissions or pollution).
The most essential part remains the final two chapters, where all the technologies listed in the previous section are any longer analysed in terms of energy input and power output but in terms of changes these actually brought in human history: interesting considerations are brough on how the increase in each individual’s energy consumption may shape his preferences (from primary to most ephemeral needs), countries’ GDP and how energy access may be – or not – a reason for geopolitical tensions.
In line with Bill Gates, whose Smil is one of favourite authors, while reading the book I questioned myself “Am I ever going to be able to understand all of this?”. The amount of calculations and numbers that the reader has to face since the very first pages, is quite overwhelming (for readers which are addressing energy related topics for the first time, referring to the addenda may reveal essential for easing the interpretation). For each supplementary in-depth information box, could probably be written a book aside. I am fascinated by the ability of the author to cover such an extensive topic in such a depth, to internalize all this information it will be probably necessary a second read.
Unfortunately, the author found too hazardous to make any statement on the future of energy. “The only certainty is that the chances of succeeding in the unprecedent question to create a new energy system compatible with the long-term survival of high energy civilization remain uncertain.” I found this a missing opportunity on raising the attention of the public on ongoing international discussion such as the one hydrogen. Should we expect a follow-up soon? In the meantime, reading Smil’s Growth: from microorganisms to megacities may be a good complement to chapter 6 and 7.
Giulia Vaglietti, Ph.D candidate Extreme weather events and land use changes: assessment of deforestation drivers
 Smil, Vaclav (2018), «Energy and Civilization: a history», The MIT Press, 552p.