As the world continues to warm, historians are increasingly exploring how past populations responded to climate changes, including those set in motion by natural forces before the onset of industrialization. Many “climate historians” aim not only to provide more accurate or more interesting accounts of the past, but also to develop useful insights into the likely consequences of present-day warming. With “Climate and Society in Europe”, Christian Pfister and Heinz Wanner skillfully summarize some of their most important findings, and explain why they matter today.
Climate history has long focused on the last millennium in Europe. The reasons are many. Evidence for past climate change is easy to come by in Europe, for example, and not only because its many archives are well-stocked with archival evidence that records weather. The continent also abounds with natural archives full of proxy sources – such as tree rings – that when carefully interpreted can precisely reveal the influence of climate changes in regional or local environments. Moreover, the climate changes that unfolded for natural reasons before the onset of industrialization – most importantly the Little Ice Age (LIA), between roughly the fourteenth and nineteenth centuries – substantially altered European temperatures for decades at a time, in ways that are not always as easily visible in other continents.
So while scholars in other disciplines have identified social responses to climate change all over the world, climate historians have until recently concentrated on Europe. For about five decades, geographer-historian Christian Pfister has been a leading figure in this scholarship. Beginning in the 1970s, he developed methods still used today for identifying or “reconstructing” climate changes using documentary sources, and for discerning the influence of climate change on human affairs. Geographer-climatologist Heinz Wanner, meanwhile, assumed leading roles in paleoclimatology – a division of climatology that concentrates on the past – and eventually established some of the leading institutions that support efforts at reconstructing climate using natural archives. Together, Pfister and Wanner are ideally suited to survey the influence of climate change in the continent and millennium most often considered by climate historians.
The partnership between Pfister and Wanner helps “Climate and Society in Europe” stand out from the many other efforts to survey the history of human responses to climate change (including a raft of recent books that cover considerably more time and space with considerably less accuracy). Climate historians can struggle to accurately interpret climate reconstructions, and as a result have mistakenly concluded that periods such as the LIA were comparable to recent warming in magnitude or global scope. Natural scientists, meanwhile, are often too eager to conflate correlation with causation in studies that identify contemporaneous climatic and social changes. Co-authoring can reduce the likelihood of these blunders, so it is no surprise that Pfister and Wanner for the most part consider changes in society and climate with equal and unusual rigor.
This equitable distribution of focus also means that “Climate and Society in Europe” lavishes attention on such topics as how climate may be reconstructed (using “specific statistical techniques”); how Earth’s climate system works (with all the “non-linear interactions” responsible for its complex stochastic variability); and why it comes to change (owing, before recent warming, to a constellation of diverse “forcings”) (p. 35/111). There are graphs, maps, and acronyms galore – all of which will be very welcome to specialists and their students. Other historians, however, may find the level detail unnecessary, to say nothing of a broader audience. The book’s tendency to slide forwards and backwards in time, occasionally while transitioning between different disciplines and topics, may also confuse some readers.
There are also places where the structure of the book may leave readers with a misleading impression of past climate change. For example, the book’s initial description of the Northern Hemisphere climate over the past 2,000 years initially suggests that it can be neatly divided into five distinct “sub-periods.” The most recent is, of course, our current period of extreme, human-caused warming. Of the other four, two (the “Roman Period Warming” and “Medieval Warm Period”) were warm, owing to “the dominance of a quiet and stable Sun and the absence of any stronger volcanic events,” (p. 49) while two (the “Dark Ages Cooling Period” and LIA) were cold.
Climate historians will instantly recognize this framing, though they may use different terms for the warm and cold periods (such as the “Roman Climatic Optimum,” or the “Late Antique Little Ice Age”). Yet they may at first question the implication – communicated most clearly in one particularly striking table (p. 49) – that climatic regimes smoothly transitioned from one state to another, with roughly simultaneous timing across the whole northern hemisphere. They may initially wonder why the book does not clearly explain that we have more and more precise evidence for recent climatic periods – such as the LIA – than older ones. There is not enough data to conclude, for example, that the Roman Climatic Optimum indeed affected all or most of the northern hemisphere.
It is likely that many students using the book will consult only its initial descriptions of climate change over the past two millennia. Yet the ones who keep reading – for several hundred pages – will discover a wealth of essential detail: about the seasonality of past climatic changes, for example, or the differences in how those changes manifested from region to region. In these passages, the concept of a “Boreal Little Ice Age” – a LIA that manifested differently and for longer across much of the northern hemisphere than it did elsewhere – is particularly helpful. It is therefore essential that their teachers encourage their students to read the whole book, lest they be left with an inaccurate or incomplete understanding of how Europe’s climate has changed.
Any book that spans 2,000 years and covers an entire continent must inevitably simplify the complex reality of the past. This is especially true for a book that devotes equal attention to climate science and history. Nevertheless, in those passages when the book concludes, for example, that “the 18th century was free from long-term adverse climatic situations,” and that “a warm spell between 1718 and 1739 ushered in a third wave of population growth,” (p. 294) it does sacrifice accuracy for simplicity and clarity. Similar sentences elsewhere in the book mean that “Climate and Society in Europe” is best suited as a guide to climate reconstruction and an introduction to climate history, rather than a comprehensive survey.
Nevertheless, Pfister and Wanner have crafted an invaluable resource: a relatively concise volume that could well spur a new wave of teaching and research into the influence of climate change in European history. For students in climate science or environmental history, it provides a sound introduction to a fast-growing and increasingly important field.