Search

The practice of religions and spirituality is common in Africa. In many ways, religion may be considered as a routine of life, living and practising it either as inherited or borrowed. Religious pluralism is a reality in Africa, dating back to the 1st century up to the 19th century when Africa became a bedrock of traders and colonisers both from Europe and Asia. The paper explores plural religiosity with a view to developing a conducive atmosphere that may promote a suitable inter-religious dialogue in Africa. Largely, the most pronounced and practised religions are Christianity symbolised by the cross, Islam symbolised by the crescent, and African indigenous religion that does not have a common symbol nor sacred scriptures. We note that, for generations, religions have caused division among communities, but have in the recent years developed the quest to create good relations and dialogue with each other. Because of the diverse nature of insecurity in Africa, it is hoped that inter-religious dialogue may cause community cohesion, integration, inclusivity, and co-existence. In the wake of different types of inter-religious dialogue that are globally being researched, this paper suggests a specific inter-religious dialogue that Africans can exercise: 'dialogue for life'. Contribution: Inter-religious dialogue for life is contextual in that, it touches upon the life situations of ordinary people in society. The author argues that, by embracing it religiously, inter-religious dialogue for life shall address crucial issues such as poverty, radicalisation, terrorism, climate change, bad governance, and human trafficking that adversely affect African society. [ABSTRACT FROM AUTHOR]

Since the 1950s, divergence problems have reduced the temporal stability of tree rings in response to climate, shaken the foundations of dendroclimatology, and affected the reliability of reconstructed models based on tree rings and the accuracy of historical climate series. Therefore, it is of great importance to investigate divergence problems, which will help us to better understand the growth strategies of trees in response to climate warming and provide a scientific basis for accurate climate reconstruction and simulation of forest dynamics. This paper aims to elucidate the mechanism of divergent growth of Picea schrenkiana at high altitudes in the western Tianshan from three aspects: variations in atmospheric circulation, changes in climatic factors, and the coping strategy of trees with climate change. High spring temperatures accelerate the melting of snow cover. Large amounts of snowmelt initially replenish soil water, leading to the rapid growth of trees, but later, the continuous consumption of snowmelt reduces the available water capacity of soil, resulting in water stress on trees. The pattern of trees' response to changes in climate ranges from a pure temperature limitation to a collaborative temperature–moisture limitation. Since the 1990s, the weakening of the westerly circulation and the North Atlantic Oscillation has reduced their impacts on the hydroclimate in the Tianshan Mountains of Central Asia. The combination of heat-induced water deficit and a long-term weakening trend in atmospheric circulation has slowed tree growth over the past decade. [ABSTRACT FROM AUTHOR]

Water shortage has plagued the social development and human well-being of global closed basins. However, the hydroclimate research on different time scales in these regions remains inadequate at a global scale. In this paper, the hydrological responses from global closed basins to millennial-scale and centennial-scale cold/warm events since the Last Glacial Maximum were explored. Closed-basin lake records indicate that the westerlies-dominated closed basins are generally wetter during cold events than the corresponding warm ones on the millennial and centennial scales. In contrast, the monsoon-influenced closed basins prevail wetter climates during warm events. According to the hydroclimate simulations, precipitation seasonality plays a significant role in causing above spatial–temporal patterns. There is more winter rainfall in westerlies-dominated closed basins during cold events in the Last Glacial Maximum and Little Ice Age and more summer rainfall in monsoon-influenced closed basins during warm events in the mid-Holocene and Medieval Climate Anomaly. Under modern and future global warming, the hydroclimate changes in global closed basins show more regional differentiation, resulting in wetter mid-latitude Asian and low-latitude African closed basins but drier southwest North American and Australian closed basins. [ABSTRACT FROM AUTHOR]

The long-term evolution of deep-sea turbidity current activity is closely related to climate and sea level changes; however, the impact of abrupt climate change (e.g. millennial-scale events in high northern latitudes) is poorly known. In this paper, deep-sea turbidite records in the western part of the lower Bengal Fan were identified since the Last Glacial Maximum (LGM) to investigate the effects of abrupt climate change on the development of the Earth's largest deep-sea fan. Our records show a termination of turbidite activity in the western lower fan at 16.6 ka–15.4 ka almost contemporaneous with Heinrich 1 event (a cooling stadial in high northern latitudes). The trigger of this termination in turbidite activity may have been a sharp decrease in erosion rates during a time of relatively stable sea level and rapid source-sink processes. The subsequent episodes of the Bolling/Allerod warm interstadial and Younger Dryas cold stadial and the rapid sea level rise event that followed possibly induced adjustment of turbidity current activities in the Bengal Fan, as indicated by other published records. In summary, we show that close links exist between abrupt climate changes in the high-latitude Northern Hemisphere and deep-sea turbidity current activity in the low-latitude South Asia. • Deep-sea turbidite records in the Bengal Fan since LGM were recovered. • Termination of turbidite in the western lower fan was triggered by HS1 event. • Links between high latitudes climate and low latitudes sedimentation were revealed. [ABSTRACT FROM AUTHOR]

We examine major reorganizations of the terrestrial ecosystem around Mono Lake, California during the last deglacial period from 16,000– 9,000 cal yr BP using pollen, microcharcoal, and coprophilous fungal spores (Sporormiella) from a deep-water sediment core. The pollen results record the assemblage, decline, and replacement of a mixed wooded community of Sierran and Great Basin taxa with Alkali Sink and Sagebrush Steppe biomes around Mono Lake. In particular, the enigmatic presence of Sequoiadendron-type pollen and its extirpation during the early Holocene hint at substantial biogeographic reorganizations on the Sierran-Great Basin ecotone during deglaciation. Rapid regional hydroclimate changes produced structural alterations in pine–juniper woodlands facilitated by increases in wildfires at 14,800 cal yr BP, 13,900 cal yr BP, and 12,800 cal yr BP. The rapid canopy changes altered the availability of herbaceous understory plants, likely putting pressure on megafauna populations, which declined in a stepwise fashion at 15,000 cal yr BP and 12,700 cal yr BP before final extirpation from Mono Basin at 11,500 cal yr BP. However, wooded vegetation communities overall remained resistant to abrupt hydroclimate changes during the late Pleistocene; instead, they gradually declined and were replaced by Alkali Sink communities in the lowlands as temperature increased into the Early Holocene, and Mono Lake regressed. [ABSTRACT FROM AUTHOR]

During abrupt climate changes of the last glacial period paleorecords show large amplitude changes in the dust cycle. We use Earth System model simulations to evaluate processes operating across these events. Idealized Heinrich stadial‐like simulations show a southwards migration of tropical rainfall that dries the Sahel and reduces wet deposition causing a widespread enhancement of tropical dust loading. However, several discrepancies with marine core dust deposition reconstructions are evident. Simulations with a more limited freshwater forcing (0.4 Sv instead of 1.0 Sv) and weaker cooling over the North Atlantic (less than 3°C) show a switch in sign of the stadial dust deposition anomaly in several regions, improving agreement with paleorecords. The simulated dust cycle therefore displays in places a non‐linear response to abrupt change. The global‐mean stadial dust radiative forcing in the more realistic simulations is around −0.2 to −0.6 W m−2 and so could represent an amplifying feedback during these events. Plain Language Summary: Mineral dust in the atmosphere is mostly sourced from arid regions like the Sahara desert. The amount and geographical spread of this dust in the atmosphere is sensitive to environmental conditions such as drought. Paleoclimate records show that rapid cooling events centered on the North Atlantic during the last ice‐age also saw large increases in the rate of dust deposited over the ocean. Earth System models are a computational tool that can be used to understand the links between climate and the dust cycle. Using a series of such simulations we found that abrupt cooling events in the North Atlantic can lead to a massive increase in dust over the equatorial (tropical) regions. However, the model's response is in many places non‐linear, meaning that the change in dust is very sensitive to the magnitude of the climate changes occurring. This non‐linearity is mostly due to interactions between changes in the water cycle and the dust. We show that a less severe cooling produces a more realistic dust response when evaluated against paleo‐dust records. Since dust scatters incoming sunlight, increased atmospheric dust during these events may have amplified and even extended the cold phases. Key Points: Freshwater hosing forcing increases tropical dust loading in Earth System model simulations of the last glacial maximumSimulated response is non‐linear with forcing in some regions, particularly North AfricaWeaker events improve agreement with data and emitted dust produces a self‐amplifying feedback [ABSTRACT FROM AUTHOR]

We combine our ice-sheet and climate models to formulate a deductive theory of abrupt climate changes pertaining to Heinrich/Dansgaard–Oeschger (H/DO) cycles and the last deglaciation punctuated by the Younger Dryas (YD). Since they are all accompanied by ice-rafted debris, we posit their common origin in the calving of the ice sheet due to a thermal switch at its bed, which naturally endows abruptness to these climate signals of the millennial timescale characteristics of the ice-mass balance. To distinguish the H/DO cycles, we differentiate the thermal triggers by geothermal-heat/surface-melt in the calving of inland/coastal ice, which provide their respective freshwater sources. Since surface-melt requires post-H warmth during the glacial, but is already operative in the Holocene, the DO cycles are encased within the H cycle during the glacial, but self-sustaining in the Holocene. They otherwise share the same time signature, thus resolving this seeming puzzle of commonality without invoking unknown climate forcing. The DO cycles transcend deglaciation to produce the observed sequence, but the calving-induced freshwater flux needs to be boosted by the rerouting of continental meltwater to cause YD. We discern a key process of an eddying ocean in its millennial adjustment toward maximum entropy production (MEP), which would melt the H-induced sea ice to cause an abrupt post-H warming followed by a gradual cooling that anchors the DO cycles to form the hierarchical Bond cycle. Since the modelled anatomies resemble the observed ones, our theory may provide a robust and unified account of abrupt climate changes. [ABSTRACT FROM AUTHOR]

We present new high‐resolution pollen records combined with palaeoceanographic proxies from the same samples in deep‐sea cores SHAK06‐5K and MD01‐2444 on the southwestern Iberian Margin, documenting regional vegetation responses to orbital and millennial‐scale climate changes over the last 28 ka. The chronology of these records is based on high‐resolution radiocarbon dates of monospecific samples of the planktonic foraminifera Globigerina bulloides, measured from SHAK06‐5K and MD01‐2444 and aligned using an automated stratigraphical alignment method. Changes in temperate and steppe vegetation during Marine Isotope Stage 2 are closely coupled with sea surface temperature (SST) and global ice‐volume changes. The peak expansion of thermophilous woodland between ~10.1 and 8.4 cal ka bp lags behind the boreal summer insolation maximum by ~2 ka, possibly arising from residual high‐latitude ice‐sheets into the Holocene. Rapid changes in pollen percentages are coeval with abrupt transitions in SSTs, precipitation and winter temperature at the onset and end of Heinrich Stadial 2, the ice‐rafted debris event and end of Heinrich Stadial 1, and the onset of the Younger Dryas, suggesting extrinsically forced southwestern Iberian ecosystem changes by abrupt North Atlantic climate events. In contrast, the abrupt decline in thermophilous elements at ~7.8 cal ka bp indicates an intrinsically mediated abrupt vegetation response to the gradually declining boreal insolation, potentially resulting from the crossing of a seasonality of precipitation threshold. [ABSTRACT FROM AUTHOR]

Since the 1950s, divergence problems have reduced the temporal stability of tree rings in response to climate, shaken the foundations of dendroclimatology, and affected the reliability of reconstructed models based on tree rings and the accuracy of historical climate series. Therefore, it is of great importance to investigate divergence problems, which will help us to better understand the growth strategies of trees in response to climate warming and provide a scientific basis for accurate climate reconstruction and simulation of forest dynamics. This paper aims to elucidate the mechanism of divergent growth of Picea schrenkiana at high altitudes in the western Tianshan from three aspects: variations in atmospheric circulation, changes in climatic factors, and the coping strategy of trees with climate change. High spring temperatures accelerate the melting of snow cover. Large amounts of snowmelt initially replenish soil water, leading to the rapid growth of trees, but later, the continuous consumption of snowmelt reduces the available water capacity of soil, resulting in water stress on trees. The pattern of trees’ response to changes in climate ranges from a pure temperature limitation to a collaborative temperature–moisture limitation. Since the 1990s, the weakening of the westerly circulation and the North Atlantic Oscillation has reduced their impacts on the hydroclimate in the Tianshan Mountains of Central Asia. The combination of heat-induced water deficit and a long-term weakening trend in atmospheric circulation has slowed tree growth over the past decade.

The article explores that author said that I was fortunate to be among the younger scholars Marilyn Gaull encouraged and counseled. Late at night, I would head to my study to solicit her opinion about this or that, seek inspiration when my confidence flagged, chew fat, complain, or just tell her about what I was reading.Her responses were unfailingly generous and fully alive. Those who knew her will recognize what I mean by the last phrase.

Climatic changes threaten freshwater resources and aquatic ecosystem health in the Sierra Nevada (California, USA), which has important consequences for millions of people and the world's fifth largest economy. However, the timing and magnitude of ecological changes driven by hydroclimate oscillations remain poorly understood in California's headwater region. Here, we develop a precisely dated, annually to decadally resolved lake sediment record of ecological change from the eastern Sierra Nevada that spans the last three millennia. Diatom paleoecology reveals a detailed history of abrupt limnologic transitions, best explained by modifications in water column stratification, mixing, and nutrient status in response to changing seasonality. Seasonally stratified conditions were registered during the Late Holocene Dry Period and the Medieval Climate Anomaly, illustrating the sensitivity of fossil diatoms to well‐known periods of drought. Yet the most striking feature of the record is the uniqueness of ~1840–2016 CE: a period of singularly strong water column stratification, increased algal diversity, and reduced diatom productivity consistent with unprecedented "hot droughts." The data demonstrate that hot–dry conditions of the Industrial Era altered lake state to conditions unseen in the past ~3180 years, and suggest that regional trends identified by historical monitoring began far earlier than previously recognized. Our record illustrates the profound influence of anthropogenic climate warming on high‐elevation lakes and the ecosystem services they provide in the Sierra Nevada, which hold implications for water quality and availability in California. [ABSTRACT FROM AUTHOR]

While paleoclimate records show that the Earth System is characterized by several different tipping points, their representation within Earth System models (ESMs) remains poorly constrained. This is because historical observations do not encompass variations large enough to provoke such regime changes, and paleoclimate conditions are rarely used to help develop and tune ESMs, which potentially ignores a rich source of information on abrupt climate change. A critical example is the early to mid-Holocene "greening" and subsequent rapid desertification of the Sahara, which most ESMs fail to reproduce, casting doubt on the representation of land-atmosphere coupling and monsoon dynamics. Here, we show that this greening and abrupt termination can be successfully simulated with one ESM after optimizing uncertain model components using both present-day observations and crucially mid-Holocene (6,000 y before present) reconstructions. The optimized model displays abrupt threshold behavior, which shows excellent agreement with long paleoclimate records that were not used in the original optimization. These results suggest that in order to realistically capture climate-system thresholds, ESMs first need to be conditioned with appropriate paleoclimate information. [ABSTRACT FROM AUTHOR]