Travertine, a secondary calcite deposit formed in tectonically and geothermally active regions of the Tibetan Plateau, preserves diverse environmental signals, including evidence of past human activity. The Quesang site contains prehistoric human hand- and footprint impressions whose ages have long been debated. Here, we applied isothermal thermoluminescence dating to travertine samples, evaluating the reliability of the equivalent dose measurements and the influence of erosion on dose rate estimates. Electron spin resonance and U-Th dating were also used for cross-validation. Our results show that isothermal thermoluminescence dating provides robust and reliable ages, confirming the prehistoric origin of the hand- and footprints and resolving previous chronological controversies. Beyond Quesang, isothermal thermoluminescence dating offers a promising approach for dating human traces in travertine and other carbonate deposits, providing new insights into the timing and distribution of early human presence on the Tibetan Plateau.

Outbreaks of epidemics are human ecological disasters and have caused huge losses of human life and social disturbances in human history. But their impact on human culture has never been systematically and quantitatively studied. This study hypothesizes that such gigantic human ecological pressure would have created a great need for cultural innovations. By quantitatively examining and modeling the process using the time-series of cultural innovations and human ecological-socioeconomic proxies in European history (1000-1900 CE) based on the basic principles of causal inference, the paper demonstrates that infectious disease epidemics and socioeconomic stress stimulated the flourishment of thinkers and philosophical thoughts across different philosophies in truth, knowledge, and ethics, and promoted scientific discovery/technological innovations in a macro scale. Based on the results of Poisson regression and analysis of marginal effects, when the epidemics increased by 1, the average number of philosophical thinkers increased by 0.85, and their average impact score increased by 4.04. When the Consumer Price Index (CPI) increased by 0.1, the average number of philosophical thinkers increased by 8.9, and the average impact score increased by 29.79. The results of linear regression further show that when the epidemics increased by 1, the average scientific discoveries and technological innovations (SDTI) increased by 0.128 units; when CPI increased by 10%, the average SDTI increased by 0.15 units. Infectious disease epidemics have generally played an important role in generating cultural dynamics during the study period. The results imply that the recurrent outbreaks of the COVID-19 pandemic would likely lead to another thriving phase of cultural innovations.

Issues related to whether climate change have caused great calamites in human society are of fundamental importance to current climate change research. The causes and ecological consequences of climate change can, of course, be measured at different levels according to different scales because the natural sciences have long understood the verification of causality and importance of scale. Research regarding human responses to climate change in the humanities and social sciences has been less explicit, less precise, and more variable. The growing need for interdisciplinary work in the issues across the natural/social science boundary (gap), however, demands some common understandings about the causality and scaling issues on climate impact. We seek to facilitate the dialogue between natural and social scientists by reviewing some of the fundamental aspects of the philosophical concepts of causality and scale that can be employed in the climate change/human response study, especially as they relate to large scales of the human responses to ever-changing global climate in history. Here we present the common philosophical concepts of causality and scale in natural sciences and social sciences, examine how researchers in the field employ the philosophical concepts to verify the relationship between human societies and climate change using various samples with multiple scales and explore how to connect and break the links between climate change, human calamites and resilience at different levels of hierarchies.

Climate change has fundamentally led to social crises across Eurasia, regarded as Malthusian catastrophes, the core of which lies in resource scarcity under climate-induced stress. Societies have generally dealt with reduced resources under climatic impacts through both behavioral and mental manners. However, there is still a lack of sufficient studies to empirically examine behavioral and mental resilience to maintain or increase resources under climate change on a macro scale. This study thus selected Europe and China during the last millennium as focal regions based on several representative indicators of behavioral and mental resilience, including land input, migration, scientific and technological innovation, and philosophical thinkers. Land input and migration belong to behavior resilience, while innovation, philosophical thinkers, and their thoughts are mental resilience. Here we show that, land input and migration have expanded agricultural production, despite their non-sustained effects and potential negative costs. Innovation and cultural advancement as mental resilience would promote fundamental resilience, particularly in a long term. Besides, the study justifies that behavioral resilience strategies are reflections and fundamentally influenced by mental resilience. Overall, addressing behavioral resilience alone is insufficient when confronting climate-induced stress. A more efficient climate resilience framework must integrate both behavioral and mental approaches to relieve threats of climate change.

Multidisciplinary research has examined prehistoric human adaptation and survival in the Tibetan Plateau’s alpine and hypoxic environment. As an important prehistoric human hand and footprint site for studying prehistoric human activities, Quesang, on the central Tibetan Plateau, has witnessed prehistoric human arrivals at least twice: in the Middle Pleistocene and early-middle Holocene. Recent investigations along the gully incised by water flow of the active spring have discovered a series of prehistoric human footprints and repeated trampling marks on the residual travertine in the different locations of gully and their ichnological characteristics and ages are unknown. To determine whether and when the imprints were left by Hominin and explore their association with the surrounding environment and landform evolution, we conducted detailed stratigraphic and geomorphological analysis of travertine deposit, 3D modelling and morphological study of hand and footprints, as well as Uranium–Thorium and optically stimulated luminescence dating of hand and footprints and strata. Based on these analyses, we obtained the following results: The active hot springs formed after 17.37 ka BP, probably when the Bølling-Allerød Interstadial began. The newly discovered footprints and repeated trampling traces are ichnologically identified as Hominin traces, which were unintentionally impressed at 8.5–9.2 ka BP and 14.2 ka BP, respectively, and are related to the development of the gully. In the cold, dry, and anoxic environment of the Tibetan Plateau, the Quesang hot spring is undoubtedly a very attractive survival resource, attracting prehistoric humans to frequently patronise it for a long time. The discovery of these imprints provides new evidence of prehistoric human expansion and occupation on the Tibetan Plateau before and in the Holocene.

Rising El Niño–Southern Oscillation (ENSO) variability is expected to influence Earth’s forest ecosystems, through changes in how coordinated annual tree growth is across large spatiotemporal scales. However, the mechanisms by which changes in ENSO variability affect tree growth remains poorly understood, especially in understudied subtropical forests. We use a newly built tree ring network collected from 4,028 trees at 144 forest locations across East Asian subtropical forests (EASF) at subcontinental scales (∼2,000 km), to assess long-term influences of ENSO on the spatiotemporal variability in tree radial growth across China. Our results demonstrate a west-east dipole pattern of synchronized tree growth in EASF moisture-limited tree populations, with positive growth responses to El Nino in southeastern China, and negative growth responses in the southwestern China. Specifically, trees grew more in El Niño years in eastern populations, but less in western populations. This pattern likely results from the contrasting effects of ENSO on drought limitation along a longitudinal gradient. Our results also show that increasingly severe El Niño/La Niña years have caused a sharp rise in tree growth coherence over past 150 years in these moisture-limited populations. A further increase in climate variability, as is expected with climate change, could destabilize subtropical forest ecosystems by synchronizing tree growth to an unprecedented level. In all, our results highlight the need for further research on the ecological implications of rising synchrony, given its increasing relevance to global forest ecosystems in a time of rising climate variability.

The phenomenon of centralization or decentralization has been widely observed in archaeological research. Studies are usually related to the evolution and dynamics of culture or civilization, but less pertinent to the temporal–spatial pattern and variation of human settlement, especially the insufficient applications of statistics and spatial analyses; also, their relationship with climate change is unclear. In this study, using the one-way analysis of variance (one-way ANOVA) and standard deviational ellipse (SDE) with its parameters and frequency histogram, with thousands (>4,000) of document-based data on archaeological sites (the indicator of human settlement), two pairs of successive cultural types, i.e., Majiayao–Qijia cultures and Longshan–Yueshi cultures in both ends of northern China were compared as cross-regional cases to uncover whether the locations of prehistoric settlements with ended or started ages were (de-) centralized under the impacts of climate cooling and aridification during the well-known “4.2 ka BP event” (4200–3900 BP). The results illustrate that the “inherited” sites become more decentralized. Such a pattern embodies human resilience (including adaptation and migration) for pursuing better living conditions under the circumstances of climatic and environmental deterioration over the mid–late Holocene cultural transition, which provides some implications for the response to contemporary climate change.

The cold and hypoxic environment of the Tibetan Plateau was a major challenge for its prehistoric human occupants. The earliest known hominin occupation (or visitation) of the Tibetan Plateau was at ~200 ka, in the middle Pleistocene, and these hominins must have had survival strategies for this harsh environment. We report the discovery of 5 handprints and 17 footprints on the travertine near the outlet of the Quesang hot spring, a well-documented archeological site with well-studied hominin hand and footprints on the Tibetan Plateau. Based on ichnological analysis and U-Th dating, we found that these intentional and unintentional traces were impressed during the early to middle Holocene. Combined with the 19 previously-dated hand and footprints from around the hot spring, we conclude that this site was attractive to ancient humans who made repeated visits over a long period. The strengthened monsoon in the early and middle Holocene may have promoted the expansion of prehistoric human activity onto the central Tibetan Plateau. The frequent human activities near the Quesang hot spring imply that the widespread hot springs on the Tibetan Plateau provided resources that facilitated human survival in this cold and dry plateau region.

Studies on the spatiotemporal relationship between historical climate change and the patterns of population and war are rare. In this research, statistical methods (such as correlation test and Granger causality analysis) and visualization technique are applied to demonstrate how temperature, in terms of long-term trend and cyclic mode, fundamentally affects the temporal-spatial variations of population center and war center during imperial China (5–1911 CE). Results show that (1) the consistent southward migration of population center and war center overall accords with the macro-trend of temperature cooling over the last two millennia. (2) The extent of the outward expansion of the Chinese Empire is measured by the population center–war center distance that lengthens during warm periods but shortens in cold phases, which correspond to the north/west/northwestward advancement and south/east/eastward retreatment of war center, respectively, while population center moves within a small range. (3) The shift of population latitude precedes that of war latitude, indicating the change from ecological-demographic to social-political sphere in space. We suggest that similar to population center, the temperature-influenced ancient Hu Line, which symbolizes the disparity of population density in different regions of China, may shift by several hundred kilometers; latitudinal rather than longitudinal variations of population center and war center are more robust in history. We also find that precipitation controls war center and population center on the multicentennial scale, but not the scale focused upon in this study. These findings provide new insights and theoretical implications into the in-depth understanding of the nature–human nexus.

Concerning the ecological and economical importance of the Pearl River basin, short-term climate changes have been widely studied by using the instrumental records in the basin, but there is still a lack of long-term climatic reconstructions that can be used to evaluate the centennial scale climate anomalies. Here, we present a 237-year tree-ring width chronology from Tsuga longibracteata in the north-central Pearl River basin, with reliable coverage from 1824 to 2016. Based on the significant relationship between tree growth and mean temperature from the previous March to the previous October, we reconstructed the previous growing season (pMar-pOct) temperatures for the past 193 years, with an explained variance of 43.3% during 1958–2016. The reconstruction reveals three major warm (1857–1890, 1964–1976, and 1992–2016) and cold (1824–1856, 1891–1963, and 1977–1991) periods during 1824–2016. Comparison with other temperature sensitive proxy records from nearby regions suggests that our reconstruction is representative of large-scale temperature variations. Significant correlations of tree growth with the sea surface temperatures (SSTs) in the western Pacific Ocean, northern Indian Ocean, and Atlantic Ocean suggest that SST variability in these domains may have strongly influenced the growing season temperature change in the Pearl River basin.

The ancient Silk Road played a crucial role in cultural exchange and commercial trade between western and eastern Eurasia during the historical period. However, the exchanges were interrupted in the early 16th century CE, during the Ming dynasty. Various causes for the decline of the ancient Silk Road have been suggested. Unlike social factors, natural factors have not been adequately addressed. In this study, we use evidence from a sedimentary site (Xishawo, XSW) in Dunhuang oasis, together with analysis of historical archives, to demonstrate the occurrence of extreme droughts and desertification events in the Dunhuang area post ∼ 1450 CE, which persisted at least for decades. The desertification may be closely associated with the accessibility of the ancient Silk Road in the area, which was responsible for a steep fall in the volume of trade, as well as political chaos and mass migrations. Therefore, besides socio-economic factors, climate change may have played an important role in trade exchange between the Ming government and the West and may have even influenced the rise and decline of the ancient Silk Road.

At Quesang on the Tibetan Plateau we report a series of hand and foot impressions that appear to have been intentionally placed on the surface of a unit of soft travertine. The travertine was deposited by water from a hot spring which is now inactive and as the travertine lithified it preserved the traces. On the basis of the sizes of the hand and foot traces, we suggest that two track-makers were involved and were likely children. We interpret this event as a deliberate artistic act that created a work of parietal art. The travertine unit on which the traces were imprinted dates to between ∼169 and 226 ka BP. This would make the site the earliest currently known example of parietal art in the world and would also provide the earliest evidence discovered to date for hominins on the High Tibetan Plateau (above 4000 m a.s.l.). This remarkable discovery adds to the body of research that identifies children as some of the earliest artists within the genus Homo.

Studies about climate change and the variation of the spatial pattern of war are extremely scarce in academia at present. Therefore, the temperature series and battle coordinates in imperial China from AD 5 to 1911 are integrated in this research, and their long-term quantitative relationship is examined by employing mathematical statistics such as one-way ANOVA, as well as the spatial analytical tool, standard deviational ellipse (SDE) in ArcGIS. Meanwhile, the temperature sequence is divided into three multicentennial warm–cold cycles, which are combined with different types of war (all war, agri-nomadic conflict, and rebellion) to reveal the spatial disparity of war under the influence of secular and periodic temperature change. Results show that (1) battle longitude and battle latitude are significantly different between warm and cold phases. (2) SDEs stretch toward the north/west/northwest in warm intervals but retreat south-/east-/southeastward in cold stages. (3) SDEs generally shift southeastward over time, and the variation of latitude is more evident than that of longitude, which corresponds to the overall cooling trend throughout the past 2000 years. Based on these research findings, we conclude that temperature fundamentally regulates the spatial difference of war in imperial China via controlling agricultural and pastoral productivity. This innovative study provides a robust climatological explanation of the historical conundrum why wars in ancient China distribute with specific directions, and it also lays a foundation for spatiotemporal investigations of climate change and human responses at long-term scales in the future.

Abstract. The Ancient Silk Road played a crucial role in cultural exchange and commercial trade between western and eastern Eurasia during the historical period. However, the exchanges were interrupted in the early 16th century AD, in the Ming dynasty. Three causes of the demise of the ancient Silk Road have been suggested: (1) the thriving of the sea trade route after the great geographic discovery in the Ming dynasty; (2) frequent incursions by the Wala and Turpan kingdoms, or fighting in border areas; and (3) climate change. In this study, new evidence from a sedimentary site in Dunhuang oasis together with analysis of historical archives indicate that neither the sea trade route nor the frontier wars were the pivotal reason for the closure of the Jiayuguan Pass. Extreme droughts and desertification events, caused by climate change, occurred in the Dunhuang area, west of the Jiayuguan Pass, during ~ 1440–1460 AD. After ~ 1450 AD, desertification rendered the ancient Silk Road impassable in the area, which resulted in a steep fall in the volume of trade as well as political chaos and mass migrations. The final closure of the Jiayuguan Pass in 1539 AD and the abandonment of Dunhuang city further interrupted the operation of the ancient Silk Road.

Quantitative research on climate change and war hot spots throughout history is lacking. In this study, the spatial distribution and dynamic process of war hot spots under different climatic phases in imperial China (1–1911 CE) are revealed using Emerging Hot Spot Analysis (EHSA), based on the Global Moran’s Index for testing the degree of spatial autocorrelation or dependency. The results show that: (1) Battles were significantly clustered regardless of any climatic mode or war category. (2) Hot spots for all war were generally located in the Loess Plateau and the North China Plain during warm and wet periods, but in the Central Plain, the Jianghuai region, and the lower reaches of the Yangtze River/Yangtze River Delta during cold and dry conditions. (3) Hot spots for agri-nomadic conflict have similar patterns as those for all war, whereas rebellion hot spots expanded outward during warm and wet intervals yet contracted inward during cold and dry stages. These findings, by providing insightful evidence into the spatiotemporal patterns of war under the movements of climatic-ecological zones and geopolitical variations in ancient China, can be a starting point for future exploration of the long-term relationship between climate change and social security.

This research empirically analyzes the association between climate change, population size, and demographic crises as indicated by what we term "population checks," or major wars, epidemics, and famines from AD 1000 to AD 1900 in the Northern Hemisphere based on historical records and climate reconstructions. We conducted this study at two temporal scales: (1) the entire study period of 900 years and (2) three climate phases according to temperature (cold, mild, and warm) of 300 years each. By adopting linear and nonlinear statistical methods, we found climate change and population size to have significant roles in driving the demographic crisis at the temporal scale of the entire study period. In terms of the three climate phases of 300 years each, we find that war is more closely correlated to climate change than to population size for all three phases. However, population size itself is more likely to trigger epidemics during mild and warm phases and is more important in relation to famines than climate change during all three climate phases. This study emphasizes the importance of scale in reviewing the social past in terms of climate change and population size. Empirical evidence of large-scale demographic crises within the three climate phases could also provide a timely reference for scientists or policymakers in addressing the potential effects of global warming.

Short-term climate change in South China has been extensively studied based on meteorological or hydrological records. However, tree ring-based long-term climate change research is rare, especially in the Pearl River basin, owing to the difficulty in finding old-aged trees. Here, we present a 200-year tree ring width chronology of Pinus kwangtungensis in the east Pearl River basin with reliable coverage from 1894 to 2014. Based on the significant climate-growth relationship between tree growth and annual self-calibrating Palmer drought severity index (scPDSI) from previous May to current April, the pMay-cApr scPDSI was reconstructed for the period 1894–2014. The reconstruction reveals four dry periods during 1899–1924, 1962–1974, 1988–1994, and 2003–2014, and four wet periods during 1894–1898, 1925–1961, 1975–1987, and 1995–2002. Significant spatial correlations between the reconstructed scPDSI and the Climatic Research Unit (CRU) gridded scPDSI indicate that our reconstruction can effectively represent regional moisture variability in the Pearl River basin. Spatial correlations with global sea surface temperatures (SSTs) show that our reconstruction is negatively correlated with northern and western Pacific SSTs while positively correlated with eastern Pacific SSTs, suggesting that SST variability in these domains strongly affects moisture change in the Pearl River basin.

The Yellow River has caused suffering to people with its devastating floods throughout human history. Understanding the occurrence of Yellow River floods and their relationship with climate change is crucial for sustainable water governance in North China. Here we synthesize historical and climatic records in the Yellow River basin to investigate their relationship during the past two millennia. Based on historical archives of river floods and levee breaches, we developed a decadally resolved Yellow River flooding frequency record from 221 BCE to 1949 CE, which provides a rare chance to perceive the river’s long-term flood dynamics. As revealed, the Yellow River flooding can be divided into two distinct stages: an early stage of low-frequency floods from the 220s BCE to the 890s CE; and a late stage of high-frequency floods during the 900s–1940s CE. A substantial increase in flooding frequency around the 10th century fell within the transition period into the Medieval Climate Anomaly (MCA), during which the Yellow River basin featured warm and wet climate conditions. Coincidentally, human management of the Yellow River intensified as a response to more severe and frequent floods. The intense river management persisted thereafter and resulted in the super-elevation of the riverbed, which made the river more prone to flooding. Consequently, the Yellow River flooding frequency remained high even after entering the Little Ice Age, during which the river basin featured cool temperature and reduced precipitation. Our study suggests that the dramatic transition from a previous cool, dry into a warm, wet climate during the MCA period triggered intense human management of river channels and the establishment of the flood-prone nature of the Yellow River.

Humans possess limited knowledge on what generated cultural dynamics to strengthen human resilience to overcome climate-induced stresses. Although the highly developed mental ability of humans could have enabled significant human resilience in history, no study has empirically explained or has even scientifically confirmed how and when such dynamics arose. To fill the current research gap, this study therefore explores the associations among climatic conditions, the evolutional dynamics of human thinkers and their thoughts, and human ecological-socioeconomic conditions in the past 2500 years in Europe. Results from quantitative modellings and causal analyses confirm that climatic-ecological stresses led to human ecological-socioeconomic crises, and thereby dramatically increased twice of the thinkers' number and their thoughts' impact across different philosophies in truth, knowledge, and ethics for adaptation at multi-decadal to centennial temporal scales, especially in spirituality oriented mentality. The process of the stress-generated cultural dynamics displays some similarities with the stress-induced mutagenesis in organism evolution. Ultimately, climatic-ecological stresses prompt the escalation in the number of thinkers and impacts of their thoughts and flourishing of philosophy. Such stress-regenerated cultural dynamics imply that the current climate change threat may stimulate another thriving phase of cultural selection and lift humans to the next homeostatic plateau of civilization. Findings also extend the cognate scope of psychological, sociological, and civilization studies.

This study examines China's urban rural transition in the process of development and change. Regarding tourism as a discourse of difference, it focuses on a rural ethnic community, Jiabang, in Southwest China. It aims to highlight the role of tourism in providing a stimulus for the creation of a local group identity that subverts wider discourses of rural areas. With the goal of understanding how toured places are imagined, presented and consumed, this study utilises mixed data sources collected from tourism promotional materials and ethnographic fieldwork. The findings suggest that the forces behind the touristic place creation and consumption are both integral to and the result of the changing attitudes and perceptions of people and places in contemporary China.