Historians, superhistory, and climate change

J.R. McNeill

That we are now in an age of rapid climate change is disputed in only in a few places, and there mainly for political purposes. Concern over what changing climate might mean has motivated a surge of research into climate history, using all manner of proxy evidence to inquire into temperature conditions, droughts and floods, the frequency of hurricanes and other major storms, El Niño events, and much else besides.

Only a small proportion of this new evidence on climate history comes from textual sources, the familiar terrain of the historian. Instead it comes from tree rings, ice cores, speleothems (mineral deposits in caves), fossil pollen, marine corals, varves (layers of silt or clay on the seafloor) among other places. Climate history is undergoing a renaissance thanks to all these new data. At the same time, as I will explain below, new evidence of other sorts, pertaining to other sorts of history, is also cascading forth.

Fifty or sixty years ago, under the influence of Fernand Braudel and his friends, professional history took a turn toward the social sciences. Thirty years ago, under the influence of other French scholars, no friends of Braudel, professional history took a "linguistic turn". Now it looks to be taking a "natural science turn". Historians seem to be rather like windmills, turning this way and that in response to the prevailing winds of other intellectual disciplines. There is nothing wrong with that. Surely it is often preferable to adjust one's research methods in response to innovations, whether they come from physics or from literary studies, rather than to remain resolutely unaffected by changes in intellectual life.

In this chapter, I will try to explain some of the opportunities and challenges presented by the volcano-like eruption of new historical data from the natural sciences, with special attention to climate data and what some prominent historians have thought about climate. I will also raise the question of how the new data might affect the choices historians make about the scales on which they pursue their research, in particular the logic of selecting a global scale.

Superhistory and why historians need to overcome the text fetish

The past, always a foreign country, is growing more foreign to textbased historians.

If historians wish to improve their – our – ability to address puzzles from the past (and for that matter to remain central in the study of history), they – we – need to embrace what is fast becoming superhistory. Superhistory amounts to a methodological revolution by which textual evidence jostles together with that of ice cores, marine sediments, peat bogs, stable isotopic ratios, and the human genome – and a few other genomes as well. The revolution takes historians to new terrain, to geo-archives and bio-archives, as well as to the more familiar archives containing old documents. Climate history is part of this revolution, so far perhaps the biggest part.

While careful analysis of documentary texts is the bread and butter of the historical method, historians for at least a century have found ways to use other sources such as art, literature, and the findings of archeologists. For those times and places at which abundant texts, art, and archeology overlap, such as the Roman Mediterranean of the first and second centuries CE, the interplay among specialists using different sorts of sources is a long tradition and a fruitful one. Such melding of sources has yielded information and insights rarely matched for times and places with fewer texts, less surviving art, or low appeal to archeologists. So superhistory has its precedents, and perhaps should be regarded as an expansion upon a methodological tradition (Myrdal 2012).

Superhistory nudges us, and perhaps drives us, in the direction of global history. Texts come in languages, and those languages sometimes correspond to political structures such as states and nations. Japanese is spoken in Japan and almost nowhere else; similarly with Danish and Denmark. Thus text-based historians who know these languages are tempted to write their histories on the national scale or smaller. Moreover, much textual documentation has been produced by bureaucrats employed by states and concerns the business of states. Thus textual history – what we still call history – exhibits a strong bias toward the affairs of nations and states. It encourages historians to accept nations and states as appropriate units of analysis, which for some questions they are and for others they are not. This tendency towards national-scale history has probably weakened in recent decades; the advent of superhistory will weaken it further.

The evidence of superhistory bears much thinner relationships to nations and states, and encourages historians to play around with other units of analysis, both larger and smaller. Of course, textual historians for centuries have worked on a variety of scales. Some attempted global history or thematically defined subsets of global history, such as warfare, marriage, or agriculture. The new torrents of climate evidence and the genomic data easily lend themselves to global-scale analyses. Thus the evidence from the natural sciences that is now spewing forth invites a new generation of historians to adopt world-historical perspectives. And those scholars already employing world history perspectives probably find the new evidence of superhistory more interesting, exciting, and compatible with their ambitions than do other historians.

Superhistory bears a cousinly resemblance to Big History. Scholars such as David Christian (in Australia) and Fred Spier (in the Netherlands) have spearheaded a very long-term perspective on human affairs, which they call Big History. It involves situating the human story inside the story of life on Earth, inside the story of Earth, inside the story of the solar system, our galaxy, our Universe. At this scale, mind-boggling for most historians, Christian and Spier find patterns that are not readily visible on the brief time scales familiar to historians and archeologists. They see, for example, recurrent stories of energy capture and advancing complexity, in celestial bodies and civilizations alike, over time (Christian 2005; Spier 2010).

Big History, moreover, necessarily requires a plurality of sources, disciplines, and perspectives. Big historians such as...