Human responses to hydroclimate fluctuations over the last 200 kyr in Ethiopia

2020 ◽  
Author(s):  
Frank Schäbitz ◽  
Verena Foerster ◽  
Asfawossen Asrat ◽  
Andrew S. Cohen ◽  
Melissa S. Chapot ◽  
...  
Keyword(s):  
Climate Change ◽  
Environmental Change ◽  
Environmental Changes ◽  
Homo Sapiens ◽  
Human Mobility ◽  
Regional Scale ◽  
Eastern Africa ◽  
Southern Ethiopia ◽  
Ethiopian Rift ◽  
Mobility Patterns

<p><span>Humans </span><span>have been adapting to more demanding habitats in the course of their evolutionary history</span><span>. </span><span>Nevertheless</span><span>, environmental changes coupled with overpopulation naturally limit competition for resources. In order to find such limits, reconstructions of climate and </span><span>population changes </span><span>are increasingly used for the continent of our origin, Africa.</span> <span>However, </span><span>continuous and high-resolution records of climate-human interactions are still scarce. </span></p><p><span>Using a 280 m sediment core from Chew Bahir*, a wide tectonic basin in southern Ethiopia,</span> <span>we reconstruct the paleoenvironmental conditions during the development of <em>Homo sapiens.</em> The complete multiproxy record of the composite core covers the last ~600 ka </span><span>, allowing tests of hypotheses about the influence of climate change on human evolution and technological innovation from the Late Acheulean to the Middle/Late Stone Age, and on dispersal within and out of Africa</span><span>. </span></p><p><span>Here we present results from the uppermost 100 meters of the Chew Bahir core, spanning the last 200 kiloyears (ka). </span><span>The record shows two modes of environmental change that are associated with two types of human mobility. The first mode is a long-term trend towards a more arid climate, overlain by precession-driven wet-dry alternation. Through comparison with the archaeological record, humid episodes appear to have led to the opening of ‘green’ networks between favourable habitats and thus to increased human mobility on a regional scale. The second mode of environmental change resembles millennial-scale Dansgaard-Oeschger and Heinrich events, which seem to coincide with enhanced vertical mobility from the Ethiopian rift to the highlands, especially in the time frame between ~65–21 ka BP. The coincidence of climate change and human mobility patterns help to define the limiting conditions for early <em>Homo sapiens</em> in eastern Africa.</span></p><p><span>___________________</span></p><p><span>*</span> <span>cored in the context of HSPDP (<em>Hominin Sites and Paleolakes Drilling Project</em>) and CRC </span><span>(<em>Collaborative Research </em><em>Centre</em>) 806 “<em>Our way to Europe</em>”</span></p>

scholarly journals Farmers’ Perspective on Agriculture and Environmental Change in the Circumpolar North of Europe and America

Land ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 190 ◽  
Author(s):  
Christopher Poeplau ◽  
Julia Schroeder ◽  
Ed Gregorich ◽  
Irina Kurganova
Keyword(s):  
Climate Change ◽  
Environmental Change ◽  
Online Survey ◽  
Environmental Changes ◽  
Biogeochemical Cycles ◽  
Small Scale ◽  
Local Market ◽  
Food Transport ◽  
Circumpolar North ◽  
Global Biogeochemical Cycles

Climate change may increase the importance of agriculture in the global Circumpolar North with potentially critical implications for pristine northern ecosystems and global biogeochemical cycles. With this in mind, a global online survey was conducted to understand northern agriculture and farmers’ perspective on environmental change north of 60° N. In the obtained dataset with 67 valid answers, Alaska and the Canadian territories were dominated by small-scale vegetable, herbs, hay, and flower farms; the Atlantic Islands were dominated by sheep farms; and Fennoscandia was dominated by cereal farming. In Alaska and Canada, farmers had mostly immigrated with hardly any background in farming, while farmers in Fennoscandia and on the Atlantic Islands mostly continued family traditions. Accordingly, the average time since conversion from native land was 28 ± 28 and 25 ± 12 years in Alaska and Canada, respectively, but 301 ± 291 and 255 ± 155 years on the Atlantic Islands and in Fennoscandia, respectively, revealing that American northern agriculture is expanding. Climate change was observed by 84% of all farmers, of which 67% have already started adapting their farming practices, by introducing new varieties or altering timings. Fourteen farmers reported permafrost on their land, with 50% observing more shallow permafrost on uncultivated land than on cultivated land. Cultivation might thus accelerate permafrost thawing, potentially with associated consequences for biogeochemical cycles and greenhouse gas emissions. About 87% of the surveyed farmers produced for the local market, reducing emissions of food transport. The dynamics of northern land-use change and agriculture with associated environmental changes should be closely monitored. The dataset is available for further investigations.

Should we turn the tent? Inuit women and climate change

2011 ◽  
Vol 34 (1) ◽  
pp. 151-165 ◽  
Author(s):  
Martha Dowsley ◽  
Shari Gearheard ◽  
Noor Johnson ◽  
Jocelyn Inksetter
Keyword(s):  
Climate Change ◽  
Environmental Change ◽  
Social Impact ◽  
Environmental Changes ◽  
Social Changes ◽  
Secondary Effects ◽  
The Social ◽  
Women’S Perceptions ◽  
Inuit Knowledge ◽  
Women's Role

Abstract Most of the climate change literature for Arctic Canada in the social sciences has focused on men’s knowledge and experiences. Drawing on research from Qikiqtarjuaq and Clyde River, Nunavut, we explore Inuit women’s perspectives on recent environmental changes, many of which are often attributed to climate change by Inuit or others. We divide issues resulting from environmental change into primary and secondary effects. Primary effects are changes in environmental features that affect, for example, hunting, fishing, and travelling. Secondary effects occur in the community as a result of environmental change. These include changes in the use and condition of country products like seal skins, and the psychological and social impact of environmental changes, such as going out on the land less often due to fear of dangerous conditions. We also offer a preliminary discussion on women’s role in responses to climate change, through their often dominant economic and political roles in their communities, the territory, and various wider global governance fora. Our research indicates that gender helps shape Inuit knowledge of environmental change, as well as social responses to perceptions of change. By examining women’s perceptions of environmental change, we draw attention to the social aspects and also highlight how women can contribute to adaptation, not only to physical changes but also to the resulting social changes.

scholarly journals Simulating the spatiotemporal variations in aboveground biomass in Inner Mongolian grasslands under environmental changes

2021 ◽  
Vol 21 (4) ◽  
pp. 3059-3071
Author(s):  
Guocheng Wang ◽  
Zhongkui Luo ◽  
Yao Huang ◽  
Wenjuan Sun ◽  
Yurong Wei ◽  
...  
Keyword(s):  
Climate Change ◽  
Aboveground Biomass ◽  
Large Scale ◽  
Environmental Changes ◽  
Regional Scale ◽  
Future Climate Change ◽  
Desert Steppe ◽  
Meadow Steppe ◽  
Grassland Type ◽  
Spatiotemporal Changes

Abstract. Grassland aboveground biomass (AGB) is a critical component of the global carbon cycle and reflects ecosystem productivity. Although it is widely acknowledged that dynamics of grassland biomass is significantly regulated by climate change, in situ evidence at meaningfully large spatiotemporal scales is limited. Here, we combine biomass measurements from six long-term (> 30 years) experiments and data in existing literatures to explore the spatiotemporal changes in AGB in Inner Mongolian temperate grasslands. We show that, on average, annual AGB over the past 4 decades is 2561, 1496 and 835 kg ha−1, respectively, in meadow steppe, typical steppe and desert steppe in Inner Mongolia. The spatiotemporal changes of AGB are regulated by interactions of climatic attributes, edaphic properties, grassland type and livestock. Using a machine-learning-based approach, we map annual AGB (from 1981 to 2100) across the Inner Mongolian grasslands at the spatial resolution of 1 km. We find that on the regional scale, meadow steppe has the highest annual AGB, followed by typical and desert steppe. Future climate change characterized mainly by warming could lead to a general decrease in grassland AGB. Under climate change, on average, compared with the historical AGB (i.e. average of 1981–2019), the AGB at the end of this century (i.e. average of 2080–2100) would decrease by 14 % under Representative Concentration Pathway (RCP) 4.5 and 28 % under RCP8.5. If the carbon dioxide (CO2) enrichment effect on AGB is considered, however, the estimated decreases in future AGB can be reversed due to the growing atmospheric CO2 concentrations under both RCP4.5 and RCP8.5. The projected changes in AGB show large spatial and temporal disparities across different grassland types and RCP scenarios. Our study demonstrates the accuracy of predictions in AGB using a modelling approach driven by several readily obtainable environmental variables and provides new data at a large scale and fine resolution extrapolated from field measurements.

Education on Global Climate and Environmental Change in University of China

2013 ◽  
Vol 838-841 ◽  
pp. 3195-3198
Author(s):  
Jian Cheng Kang ◽  
Xiaochen Su
Keyword(s):  
Climate Change ◽  
Environmental Change ◽  
Environmental Changes ◽  
Global Climate ◽  
Earth System ◽  
Ecological Civilization ◽  
Environment Change ◽  
Climate And Environmental Change ◽  
The Earth ◽  
Normal University

Global Climate and Environmental Change is an international hot field. To enhance native awareness on climate change is one mission of "State Policy and Action on Climate Change 2009 in China". As an implement, a course on Global Climate and Environmental Change has been opened in Shanghai Normal University since 2005. The course includes three fields. In the first field, it is introduced on which problems and harms have been caused from Global Climate and Environmental Changes according to UNEP Year Books 2003~2013. In the second field, to introduce the Earth System and Climate-Environment Change. In the third part, the hot climate-environmental issues are analyzed and discussed. By joining this course, the students have understanding earth system science and global change. It helped students to set up the view of ecological civilization of the harmonious development between human and nature, inspire students responsibility to protect the earth. During past 8 year, there were 4 to 5 classes opening for different levels in Shanghai Normal University for each year, more than 1000 students joined the study in the course.

scholarly journals Annual rhythms that underlie phenology: biological time-keeping meets environmental change

2013 ◽  
Vol 280 (1765) ◽  
pp. 20130016 ◽  
Author(s):  
Barbara Helm ◽  
Rachel Ben-Shlomo ◽  
Michael J. Sheriff ◽  
Roelof A. Hut ◽  
Russell Foster ◽  
...  
Keyword(s):  
Climate Change ◽  
Environmental Change ◽  
Environmental Conditions ◽  
Homo Sapiens ◽  
Thermal Conditions ◽  
Biological Processes ◽  
Anthropogenic Influences ◽  
Public Concern ◽  
Biological Time ◽  
Annual Rhythms

Seasonal recurrence of biological processes (phenology) and its relationship to environmental change is recognized as being of key scientific and public concern, but its current study largely overlooks the extent to which phenology is based on biological time-keeping mechanisms. We highlight the relevance of physiological and neurobiological regulation for organisms’ responsiveness to environmental conditions. Focusing on avian and mammalian examples, we describe circannual rhythmicity of reproduction, migration and hibernation, and address responses of animals to photic and thermal conditions. Climate change and urbanization are used as urgent examples of anthropogenic influences that put biological timing systems under pressure. We furthermore propose that consideration of Homo sapiens as principally a ‘seasonal animal’ can inspire new perspectives for understanding medical and psychological problems.

scholarly journals Projected Impacts of Climate Change on the Physical and Biogeochemical Environment in Southeast Asian Seas

2021 ◽  
Author(s):  
Susan Kay ◽  
Arlene L. Avillanosa ◽  
Victoria V. Cheung ◽  
Ngoc Hung Dao ◽  
Benjamin J. Gonzales ◽  
...  
Keyword(s):  
Climate Change ◽  
Environmental Change ◽  
21St Century ◽  
Regional Scale ◽  
Coastal Communities ◽  
Small Scale ◽  
Biogeochemical Model ◽  
Temperature Changes ◽  
Natural Systems ◽  
Impacts Of Climate Change

Abstract The seas of Southeast Asia are home to some of the world’s most diverse ecosystems and resources that support the livelihoods and wellbeing of millions of people. Climate change will bring temperature changes, acidification and other environmental change, with uncertain consequences for human and natural systems in the region. We present the first regional-scale projections of change in the marine environment up to the end of 21st century. A coupled physical-biogeochemical model with a resolution of 0.1° (approximately 11 km) was used to create projections of future environmental conditions under two greenhouse gas scenarios, RCP4.5 and RCP8.5. These show a sea that is warming by 1.1–2.9°C through the 21st century, with surface pH falling by up to 0.02 and dissolved oxygen decreasing by 5 to 13 mmol m− 3. Changes for different parts of the region, including four sensitive coastal sites, are presented. The changes reach all parts of the water column and many places are projected to experience conditions well outside the range seen at the start of the century. Altered species distribution and damage to coral reefs resulting from this environmental change would have consequences for biodiversity, for the livelihoods of small-scale fishers and for the food security of coastal communities across the region. Projections of this type are a key tool for communities planning how they will adapt to the challenge of climate change.

scholarly journals Age of the oldest Homo sapiens from eastern Africa

2021 ◽  
Author(s):  
Céline Vidal ◽  
Christine Lane ◽  
Asfawossen Asrat ◽  
Dan Barfod ◽  
Emma Tomlinson ◽  
...  
Keyword(s):  
Explosive Eruption ◽  
Homo Sapiens ◽  
Modern Human ◽  
Eastern Africa ◽  
Ethiopian Rift ◽  
Tephra Layer ◽  
Main Ethiopian Rift ◽  
Minimum Age ◽  
Geochemical Analyses ◽  
Human Fossils

Abstract Efforts to date the oldest modern human fossils in East Africa, from Omo-Kibish and Herto in Ethiopia, have drawn on a variety of chronometric evidence, including 40Ar/39Ar ages of stratigraphically-associated tuffs. The generally-accepted ages for these fossils are ca. 196 thousand years (ka) for the Kibish Omo I and ca. 160-155 ka for the Herto hominins. However, stratigraphic relationships and tephra correlations that underpin these estimates have been challenged. Here, we report new geochemical analyses that link the Kamoya Hominin Site (KHS) Tuff, which conclusively overlies the Kibish Formation member containing Omo I, with a major explosive eruption of Shala volcano in the Main Ethiopian Rift. By dating the proximal deposits of this eruption, we obtain a new minimum age for the Omo fossils of 212±16 ka. Contrary to previous arguments, we also show that the KHS Tuff does not correlate with another widespread tephra layer, the Wadaido Vitric Tuff (WAVT), and therefore cannot anchor a minimum age for the Herto fossils. Shifting the age of the oldest known Homo sapiens fossils in eastern Africa to before ~200 ka is consistent with several independent lines of evidence for greater antiquity to the modern human lineage.

scholarly journals Modelling Soil Carbon Content in South Patagonia and Evaluating Changes According to Climate, Vegetation, Desertification and Grazing

2018 ◽  
Vol 10 (2) ◽  
pp. 438 ◽  
Author(s):  
Pablo Peri ◽  
Yamina Rosas ◽  
Brenton Ladd ◽  
Santiago Toledo ◽  
Romina Lasagno ◽  
...  
Keyword(s):  
Climate Change ◽  
Vegetation Index ◽  
Environmental Changes ◽  
Regional Scale ◽  
Monitoring Network ◽  
Stepwise Multiple Regression ◽  
Linear Regression Models ◽  
Erosion Processes ◽  
Precipitation Seasonality ◽  
Southern Patagonia

In Southern Patagonia, a long-term monitoring network has been established to assess bio-indicators as an early warning of environmental changes due to climate change and human activities. Soil organic carbon (SOC) content in rangelands provides a range of important ecosystem services and supports the capacity of the land to sustain plant and animal productivity. The objectives in this study were to model SOC (30 cm) stocks at a regional scale using climatic, topographic and vegetation variables, and to establish a baseline that can be used as an indicator of rangeland condition. For modelling, we used a stepwise multiple regression to identify variables that explain SOC variation at the landscape scale. With the SOC model, we obtained a SOC map for the entire Santa Cruz province, where the variables derived from the multiple linear regression models were integrated into a geographic information system (GIS). SOC stock to 30 cm ranged from 1.38 to 32.63 kg C m−2. The fitted model explained 76.4% of SOC variation using as independent variables isothermality, precipitation seasonality and vegetation cover expressed as a normalized difference vegetation index. The SOC map discriminated in three categories (low, medium, high) determined patterns among environmental and land use variables. For example, SOC decreased with desertification due to erosion processes. The understanding and mapping of SOC in Patagonia contributes as a bridge across main issues such as climate change, desertification and biodiversity conservation.

scholarly journals 46 000 years of alternating wet and dry phases on decadal to orbital timescales in the cradle of modern humans: the Chew Bahir project, southern Ethiopia

2014 ◽  
Vol 10 (2) ◽  
pp. 977-1023 ◽  
Author(s):  
V. Foerster ◽  
A. Junginger ◽  
A. Asrat ◽  
H. F. Lamb ◽  
M. Weber ◽  
...  
Keyword(s):  
Human Evolution ◽  
High Latitude ◽  
Environmental Changes ◽  
Climatic Variability ◽  
Southern Ethiopia ◽  
Ethiopian Rift ◽  
Environmental Response ◽  
Climate Shifts ◽  
Decadal Climate ◽  
Abrupt Shifts

Abstract. Rapid changes in environmental conditions are considered to be an important driver for human evolution, cultural and technological innovation, and expansion out of Africa. However, the nature of these environmental changes, their amplitude and correlation with steps in human evolution is the subject of current debates. Here we present a high-resolution (~3–12 yr) and well-dated (32 AMS 14C ages) lake-sediment record of the last 46 000 yr from the Chew Bahir basin in the southern Ethiopian Rift. The record was obtained from six cores along a NW–SE transect across the basin, which has been selected as the drilling location within the ICDP Hominin Sites and Paleolakes Drilling Project (HSPDP). Multi-proxy data and the comparison between the transect coring sites provide initial insight into intra-basin dynamics and major mechanisms controlling the sedimentation of the proxies that was used to develop a basic proxy concept for Chew Bahir for the last two wet-dry cycles. The environmental response to orbitally induced sinusoidal insolation changes is usually nonlinear, as climate changes abruptly compared to changes in the forcing, or gradual but punctuated by multi-decadal intervals of drier conditions. The second major control on the environment is millennial-scale climate variability lasting ~1500 yr, similar in duration to the high-latitude Dansgaard–Oeschger cycles and Heinrich events including the Younger Dryas cold reversal at the end of the last glacial, mostly causing abrupt shifts from extreme arid to wet conditions. The duration and character of orbitally induced, high-latitude controlled, and multi-decadal climate shifts provides important constraints for the adaptation of humans to the changing environment. Therefore, Chew Bahir is a perfect site to study and understand climatic variability on different timescales.

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