http://ruby.fgcu.edu/courses/twimberley/envirophilo/wanner.pdf

Mid- to Late Holocene climate change: an overview

A rapidly growing body of research examines whether human conflict can be affected by climatic changes. Drawing from archeology, criminology, economics, geography, history, political science, and psychology, we assemble and analyze the 60 most rigorous quantitative studies and document, for the first time, a remarkable convergence of results. We find strong causal evidence linking climatic events to human conflict across a range of spatial and temporal scales and across all major regions of the world. The magnitude of climate's influence is substantial: for each 1 standard deviation (1σ) change in climate toward warmer temperatures or more extreme rainfall, median estimates indicate that the frequency of interpersonal violence rises 4% and the frequency of intergroup conflict rises 14%. Because locations throughout the inhabited world are expected to warm 2-4σ by 2050, amplified rates of human conflict could represent a large and critical impact of anthropogenic climate change.

/pdf/quantifying-the-influence-of-climate-on-human-conflict-4mo6ysanym.pdf

Quantifying the influence of climate on human conflict

Modern complex societies exhibit marked resilience to interannual-to- decadal droughts, but cultural responses to multidecadal-to-multicentury droughts can only be addressed by integrating detailed archaeological and paleoclimatic records. Four case studies drawn from New and Old World civilizations document societal responses to prolonged drought, including population dislocations, urban abandonment, and state collapse. Further study of past cultural adaptations to persistent climate change may provide valuable perspective on possible responses of modern societies to future climate change.

/pdf/cultural-responses-to-climate-change-during-the-late-4q5db2bl39.pdf

Cultural Responses to Climate Change During the Late Holocene

Sea-land oxygen isotopic relationships from planktonic foraminifera and speleothems in the Eastern Mediterranean region and their implication for paleorainfall during interglacial intervals

Six ice cores from Kilimanjaro provide an ∼11.7-thousand-year record of Holocene climate and environmental variability for eastern equatorial Africa, including three periods of abrupt climate change: ∼8.3, ∼5.2, and ∼4 thousand years ago (ka). The latter is coincident with the “First Dark Age,” the period of the greatest historically recorded drought in tropical Africa. Variable deposition of F – and Na + during the African Humid Period suggests rapidly fluctuating lake levels between ∼11.7 and 4 ka. Over the 20th century, the areal extent of Kilimanjaro9s ice fields has decreased ∼80%, and if current climatological conditions persist, the remaining ice fields are likely to disappear between 2015 and 2020.

https://science.sciencemag.org/content/sci/298/5593/589.full.pdf

Kilimanjaro Ice Core Records: Evidence of Holocene Climate Change in Tropical Africa

The Akkadian empire ruled Mesopotamia from the headwaters of the Tigris-Euphrates Rivers to the Persian Gulf during the late third millennium B.C. Archeological evidence has shown that this highly developed civilization collapsed abruptly near 4170 ± 150 calendar yr B.P., perhaps related to a shift to more arid conditions. Detailed paleoclimate records to test this assertion from Mesopotamia are rare, but changes in regional aridity are preserved in adjacent ocean basins. We document Holocene changes in regional aridity using mineralogic and geochemical analyses of a marine sediment core from the Gulf of Oman, which is directly downwind of Mesopotamian dust source areas and archeological sites. Our results document a very abrupt increase in eolian dust and Mesopotamian aridity, accelerator mass spectrometer radiocarbon dated to 4025 ± 125 calendar yr B.P., which persisted for ~300 yr. Radiogenic (Nd and Sr) isotope analyses confirm that the observed increase in mineral dust was derived from Mesopotamian source areas. Geochemical correlation of volcanic ash shards between the archeological site and marine sediment record establishes a direct temporal link between Mesopotamian aridification and social collapse, implicating a sudden shift to more arid conditions as a key factor contributing to the collapse of the Akkadian empire.

/pdf/climate-change-and-the-collapse-of-the-akkadian-empire-573bqqcv5m.pdf

G. Hemming

Papers

Climate change and the collapse of the Akkadian empire: Evidence from the deep sea