The south coast of Peru is part of one of the world's oldest and driest deserts. Yet, even here, where water is available, life also thrives. High in the Andes, austral summer rains give rise to rivers, which surge down the precipitous western flanks of the mountains, bringing inundations of water and rich alluvium, so that their courses are lined with lush riparian oases, and wherein agriculture and a long history of cultural trajectories flourished and waned. The peculiar aridity of this tropical coast is caused by cold seas offshore dictating a climate in a state of delicate balance affected by even the slightest changes of oceanic circulation, not least those that attend the periodic El Niño Southern Oscillation (‘ENSO’) phenomenon. This sensitivity has long led scholars of the region's archaeology to debate the role of climate in driving social change: the theme taken up here by Volker Soßna.

This book is the product of much intelligence bent with great energy towards an extremely knotty problem. It is elegantly written and beautifully set out and illustrated. Its review and distillation of secondary sources is, mostly, excellent. Yet what really sets Soßna's contribution apart is its foundation on findings from one of the most comprehensive archaeological projects to be conducted in Peru in our times: the Nasca-Palpa Archaeological Project directed by Marcus Reindel of the German Archaeological Institute. This project epitomises the virtues of a German ‘total archaeology’: well-funded, multi-disciplinary research over two decades, entailing real collaborations with the most appropriate Peruvian colleagues. The latest of many publications to emerge from the project, this book (and accompanying CD) disseminates the results of its archaeological survey, encompassing the northern Río Grande drainage from its headwaters in the high Andes, down across the floodplains of a hyper-arid coastal plain, where it joins the southern tributaries of the drainage.

For those who work on the south coast of Peru, these results include revelations, such as confirmation of the largely highland character of Late Paracas, manifest in the form of remarkable ‘flower’ structures extending high into the cabezada sierra hinterlands of the coastal rivers. For those who work in Peru more generally, they provide the first survey encompassing an entire drainage since the Virú work in the 1950s, thereby offering new insights into the waxing and waning of pan-Andean social, political and ecological interactions between coast and sierra over the three millennia from c. 1500 BC to AD 1532. And finally, archaeological data on this comprehensive scale offer the possibility of enquiring how variations in climatic and ecological diversity across more than 5000m of altitude may have affected settlement patterns over time: matters of significance well beyond the Andes.

In doing so, Soßna is at pains to identify the often glossed-over problems that attend the juxtaposition of the archaeological record with proxy evidence of past climate. All such records are inevitably highly fragmented so that merely establishing coincidence with sufficient chronological and spatial resolution is problematic enough, before demonstrating any causal linkage. Meanwhile, synthesising interpretations from weakly substantiated data in different disciplines always runs the risk of circular reasoning: “building on each other's myths”, as Renfrew (Reference Renfrew1987: 287) put it. On the one hand, then, Soßna uses Tainter's (Reference Tainter1988) classic study to define changing social complexity in the archaeological record—albeit blunted here by an over-reliance on migration as the only mechanism of change—while on the other, he draws upon work of the project's geomorphologists to reconcile local proxy evidence for climate change, in the form of loess deposits, with more distant records across the Andes (e.g. Mächtle & Eitel Reference Mächtle and Eitel2013).

Yet despite (or perhaps because of) the richness of the new archaeological record revealed herein, Soßna's interpretations are ultimately ambivalent, noting that “climate reconstruction for the Río Grande drainage, independent from the interpretation of archaeological features [. . .] is neither detailed nor free of contradiction” (p. 46, emphasis added). Archaeological features here certainly do offer powerful impressions of changed landscapes, but they lie across a continuum between rain-fed and irrigation agriculture, the latter deriving from water sources arising at distant headwaters, whose interactions with climate seemingly entail contradictions for the present, let alone for the prehistoric past. Do, for instance, strong El Niño events bring drought to the Andean hinterlands of the south coast (p. 37, and as occurred in 2016); or do they bring more rainfall (as in 1997/1998)? The effects of ENSO climate perturbations are not so easily generalised across space.

Some (e.g. Beresford-Jones et al. Reference Beresford-Jones, Lewis and Boreham2009; Hesse & Baade Reference Hesse and Baade2009) have argued that changes evident in the geoarchaeological records of the south coast were human-induced, precipitated by the intensification of agriculture, whereas others (e.g. Mächtle & Eitel Reference Mächtle and Eitel2013) see such evidence as the consequence of long-term climate changes at the desert margin. There is a refreshing humility in Soßna's reluctance to distinguish between the equifinal outcomes of these different interpretations. For it would seem that the most satisfying explanation for such change may lie in the self-enhancing feedback mechanisms acting between both climatic and socio-economic factors, leading to a gradual reduction of natural habitat and social cooperation.

Be that as it may, this book deserves to become essential reading, certainly for archaeologists of the south coast of Peru, due to its setting out of the exemplary survey data of the Nasca-Palpa Archaeological Project, but also for those working far beyond, including archaeologists concerned with the difficult but important task of unravelling interactions between climate and society in the past, not least for what that may tell us about the present, or indeed the future.