The Role of Climate in the Collapse of the Maya Civilization: A Bibliometric Analysis of the Scientific Discourse

Scrutinizing the paleoecological record of the Maya forest

Human expansion into and occupation of the New World coincided with the great transition from the Pleistocene to the Holocene epoch, yet questions remain about how we detect human presence in the paleoecological record. In the Maya area of southern Mesoamerica, archeological evidence of the human imprint is largely invisible until ∼4,000 years ago. How do environmental changes after that time correspond and relate to human impacts? Are the archeological signatures of initial settlements in the Early Preclassic detected? Later, by ∼2,000 years ago when the Maya had fully settled the landscape, how does the evidence of forest compositional changes relate to human intervention? This paper evaluates published paleoecological data in light of the rise of the Maya civilization and reflects on interpretations of how swidden agriculture and the milpa cycle impacted the environment. Evaluating the contrast between the long archeological sequence of successful Maya development and paleoecological interpretations of destructive human-induced environmental impacts requires a concordance among pollen data, archeological evidence, ethnohistoric observations, ethnological studies of traditional Maya land use, and the historical ecology of the Maya forest today.

Climate and the Decline and Fall of the Western Roman Empire: A Bibliometric View on an Interdisciplinary Approach to Answer a Most Classic Historical Question

This bibliometric analysis deals with research on the decline and fall of the Western Roman Empire in connection with climate change. Based on the Web of Science (WoS) database, we applied a combination of three different search queries for retrieving the relevant literature: (1) on the decline and fall of the Roman Empire in general, (2) more specifically on the downfall in connection with a changing climate, and (3) on paleoclimatic research in combination with the time period of the Roman Empire and Late Antiquity. Additionally, we considered all references cited by an ensemble of selected key papers and all citing papers of these key papers, whereby we retrieved additional publications (in particular, books and book chapters). We merged the literature retrieved, receiving a final publication set of 85 publications. We analyzed this publication set by applying a toolset of bibliometric methods and visualization programs. A co-authorship map of all authors, a keyword map for a rough content analysis, and a citation network based on the publication set of 85 papers are presented. We also considered news mentions in this study to identify papers with impacts beyond science. According to the literature retrieved, a multitude of paleoclimatic data from various geographical sites for the time of late antiquity indicate a climatic shift away from the stability of previous centuries. Recently, some scholars have argued that drought in Central Asia and the onset of a cooler climate in North-West Eurasia may have put Germanic tribes, Goths, and Huns on the move into the Roman Empire, provoking the Migration Period and eventually leading to the downfall of the Western Roman Empire. However, climate is only one variable at play; a combination of many factors interacting with each other is a possible explanation for the pattern of long-lasting decline and final collapse. Currently, the number of records from different locations, the toolbox of suitable analytic methods, and the precision of dating are evolving rapidly, contributing to an answer for one of the most classic of all historical questions. However, these studies still lack the inevitable collaboration of the major disciplines involved: archeology, history, and climatology. The articles of the publication set analyzed mainly result from research in the geosciences.