Mid-Late Holocene Stalagmite δ18O and δ13C Records in Naduo Cave, Guizhou Province, China

Global warming and climate anomalies have attracted worldwide attention. The study of global climate change has received increasing attention from all countries and fields worldwide. Paleoclimate research is an important way to understand past global change and environmental evolution and to simulate and predict future climate development. A stalagmite ND3 collected in Naduo Cave was used to reconstruct the history of local climate and environmental changes from 0.55 to 5.07 ka BP based on the data of 13 230Th ages and 642 groups of oxygen and carbon stable isotopes. First, according to correlation analysis, δ18O and δ13C were significantly correlated (correlation coefficient r = 0.308, n = 318, P < 0.001 ) during the 5.07–2.00 ka BP period. However, during the period of 2–0.55 ka BP, there was no significant correlation P > 0.05 . The δ18O and δ13C data indicate that the climatic environment changed asynchronously during the period of 2.00–0.55 ka BP. During the period of 5.07–2.00 ka BP, the influence of human activities was weak, and δ18O and δ13C indicate similar climatic and environmental conditions, both of which changed in the same direction (positive correlation). In other words, when δ18O was positive, it indicated weak summer monsoons and lower precipitation, which led to declines in vegetation, weakened biological activity, and decreased soil CO2 and positive δ13C. The reverse patterns were also true. Since 2.0 ka BP, the intensity of human activities and the transformation and influence of surface vegetation have increased, and native vegetation has been destroyed in large quantities. Therefore, the climatic and environmental significance indicated by δ13C and δ18O has been well demonstrated. Second, the δ18O records showed that stalagmite ND3 responded to the weak monsoon drought events of 4.2 ka BP and 2.8 ka BP in the Holocene in a discontinuous deposition manner, which brings up new directions for future research.

Potential impacts of concurrent and recurrent climate extremes on the global food system by 2030

The risk of food-supply instability is expected to increase along with the frequency and intensity of extreme agro-climatic events in many regions. Assessing the sensitivity of the global agricultural system to evolving extremes requires the probability of occurrence of such events to be estimated and their links with potential food supply and demand culminations to be established. From this perspective, in this article we implement a novel approach that can be used as a tool to inform decision-makers about the resilience of agricultural markets to climate extremes. By incorporating simulated climate-stress events into a partial-equilibrium model of interconnected agricultural commodity markets, we examine the complex manifestations of grain supply, demand and prices attributable to hazardous extremes. Market outcomes are further synthesized into coherently defined vulnerability and risk indicators. The proposed framework currently covers compound heat and water anomalies at the country level, potentially concurrent and recurrent, that impact annual crop yields and market balances in a recursive-dynamic manner until 2030. Our findings indicate that extreme-climate anomalies significantly distort expected market equilibria in the medium term. Moreover, extreme global prices may result either from climate anomalies in single key countries or from simultaneous events in many regions. Last but not least, trade and storage come forth as important alleviative mechanisms of the market uncertainty provoked by recurrent extremes.

Desert Climate Regionalization for Joshua Tree National Park and Surrounding Areas Using New Climate Network Observations

A new amalgamation of weather stations in and around Joshua Tree National Park in southeastern California, USA has allowed for objective climate analysis regionalization at a much finer scale than past studies. First, it sets a baseline for many regions within the park’s boundaries which were not subject to direct observations. Second these new observations are key to understanding shifting microclimate regimes in a desert ecosystem prone to the effects of climate change. Principal component analysis was used to regionalize the climate network based on monthly temperature and precipitation climate observations and standardized anomalies. Both the observation values and standardized climate anomalies identified regional boundaries. In general, these boundaries align with traditional ideas and past studies of the Mojave and Sonoran Deserts based on elevation (specifically the 1000m contour) for the National Park. Standardized anomaly values identified a boundary based on seasonal precipitation, while observation values identified a boundary based on elevation. The boundary line within the park is similar for both data approaches, with the boundary running along the higher western third of the park. Conversely, the two methods differ significantly in the Coachella Valley, where low elevations and low precipitation meets winter dominated seasonal precipitation. This study highlights the importance and opportunity of field observations to create climatological and ecological regionalization, as well as constructs a baseline to monitor and manage shifting desert regions in the future.

How long and how strong must a climatic anomaly be in order to evoke a social transformation? Historical and contemporaneous case studies

In recent years, scholarly interest in the nexus between climate change and human societies has risen dramatically, and many researchers from different disciplines have begun studying the possible effects of climate change and climate anomalies on past and present societies. In this article, we join this lively debate, seeking to extend it by raising, and providing possible answers to, two fundamental questions: what type of climatic anomalies can undermine social stability? What duration and intensity are necessary to instigate structural change? When attempting to answer these questions, researchers tend to view short-term climatic events, such as storms or mudslides, as “unusual” events that instigate an “unusual” reality for temporary, and measurable, time periods. We argue, instead, that gradual and more “usual” climatic events, such as prolonged droughts or extended periods of untimely rains, impact societies in a more profound and “extraordinary” manner, and it is here that our paper meets the theme of the extraordinary and the usual, the axes of the current collection of essays. Based on qualitative examination of collapse periods in western Asia and northern China during the eleventh and early twelfth centuries, and a high-resolution re-examination of the crisis in Mali at the beginning of 2010, we argue that extended climate anomalies that cause decreases in the amount of available food are the anomalies that most affect the fate of human civilizations. While people can cope with short-term climate anomalies that cause periodical food crises, lasting a year or two, extended climate anomalies that affect the availability of food, like droughts, cold spells or untimely rains, can have disastrous, long-term effects: they accelerate decisive processes, push people to migrate outside their regions of residence, increase violence and religious extremism, and, ultimately, lead to structural changes in the societies that are affected by the crises.

Why super sandstorm 2021 in North China

Severe sandstorms reoccurred in the spring of 2021 after absence for more than 10 years in North China. The dust source area, located in Mongolia, suffered destructive cooling and warming in early and late winter which loosened the land. Lacked precipitation, excessive snow melt, and strong evaporation resulted in dry soil and exiguous spring vegetation. A super-strong Mongolian cyclone developed on the bare and loose ground, and easily blew and transported large amounts of sand particles into North China. Furthermore, the top-ranking anomalies of sea ice shift in the Barents and Kara Sea and the sea surface temperatures in east Pacific and northwest Atlantic were identified to induce the aforementioned tremendous climate anomalies in dust source area. Analyses, based on large-ensemble CMIP6, yield identical results as the reanalysis data. Thus, the climate variabilities at different latitudes and synoptic disturbances jointly facilitated the strongest spring sandstorm over the recent decade.