Spread of the cycles: a feedback perspective on the Anthropocene

Environmental change and globalization dynamics in Roman Anatolia: Stabilizing an accelerating system

The role of the Great Acceleration in transitioning the Earth into a new system state invites questions about the acceleration mechanism itself. Here, we use socioeconomic and environmental datasets from Roman Western Anatolia (first c. BCE to seventh c. CE) to investigate the possible mechanisms of globalization-driven acceleration. After the Roman conquest, Anatolia experienced a rapid transition to profoundly anthropogenic landscapes, reaching hitherto unknown levels of agricultural production that remained stable for several centuries. At the socioeconomic level, as revealed by our application of social network analysis to the numismatic data, the growth dynamics continued, leading to ever greater integration. When international conflict in the seventh c. CE disrupted the connectivity, the anthropogenic landscapes rewilded. This dual-system behavior, critical transition followed by equilibrium in the socioecological realm and continued growth in the socioeconomic realm, suggests that the observed postacceleration stabilization necessitated differential balancing of negative and positive feedbacks in each domain.

Unbalanced social-ecological acceleration led to state formation failure in early medieval Poland

Rapid social-ecological intensification is a recurrent feature of human history. It occurred in different forms and contexts; its outcomes may have been sustainable or transient. Until recently, such intensifications usually accompanied state formation: Consolidation of political power was often coupled with exponential increase in human exploitation of the environment of a given area. Here, we study one such case, uniquely well-documented through our rich paleoecological, archaeological, numismatic, and literary data. Triggered by the Eurasian slave trade, the first "Polish" polity was founded in Central Europe c. 900 common era. It undertook unprecedented ecological intensification in its core territory, connected with large construction projects, and engaged in rapid territorial expansion. We provide new crucial evidence on this process by publishing here a high-resolution pollen profile from a location close to the polity's capital and by an application of social network analysis to numismatic data. This state collapsed within a few generations after its foundation. The collapse of the political elites, however, did not produce a complete social and ecological disintegration of the polity's former core region. We thus show how collapse and continuity can remain closely intertwined. Last but not least, the rich evidence on the mechanism of the collapse reveals that successful maintenance of social-ecological intensification requires reliance on a number of cultural, economic, religious, and social networks underlying the political expansion. The polity's elite lacked access to or failed to mobilize such networks, which led to its demise.

Housing inequality and settlement persistence are associated across the archaeological record

Definitions of sustainability commonly stress both systemic continuity and equality over time. However, the degree to which these two sides of sustainability might be related has not been systematically investigated. Recent theoretical and methodological insights have provided archaeologists with new tools for investigating sustainability in premodern societies. Here, we use Gini coefficients on residence size measurements as an estimate of material inequality and information on the persistence of settlements as a measure of continuity. Persistence is derived from the length of time a settlement endured in a particular state, and we assume that higher levels of persistence indicate greater adaptive capacity and resilience. We articulate an approach which allows us to combine these proxies to investigate the relationship between these two sides of sustainability and apply this to a global dataset of settlements from the last 10,000 y. We find that persistence is weakly correlated with material inequality, rather than equality, overall. We also find that this relationship grows stronger as settlement systems increase in scale and is strongest for larger sites in larger systems. This pattern may be the result of both increased functional diversity at a site level and network effects whereby residents of larger settlements were able to claim a larger share of the surplus produced by the settlement system.

Fabrication of Fe-doped biochar for Pb adsorption through pyrolysis of agricultural waste with red mud

Synthesis of metal-doped biochar have gained prominence due to their adsorption capability for heavy metal(loid)s. In this study, iron-doped biochar (Fe-BC) was fabricated through pyrolysis of waste mushroom substrate (WMS) with red mud (RM). The synthesised Fe-BC was employed as an adsorbent for Pb removal. During pyrolysis of WMS, introducing RM contributed to the enhanced syngas formation, this observation was attributed to the catalytic function of Fe species in RM. The Fe-BCs were made at three different temperatures (500, 600, and 700 °C), and their adsorption capabilities for Pb were evaluated. Among the prepared Fe-BCs, Fe-BC fabricated at 700 °C (Fe-BC-700) demonstrated the highest Pb adsorption performance (243.07 mg g-1). This performance primarily stemmed from the presence of zero-valent Fe and surface functional groups (-OH) in Fe-BC-700. Pb removal by Fe-BC-700 was dominated by surface precipitation and complexation mechanisms. Therefore, this study highlights a promising approach for producing an effective adsorbent for Pb removal from industrial wastewater by utilizing wastes such as RM and WMS.