Nonlinear landscape and cultural response to sea-level rise

Abstract

Rising sea levels have been associated with human migration and behavioral shifts throughout prehistory, often with an emphasis on landscape submergence and consequent societal collapse. However, the assumption that future sea-level rise will drive similar adaptive responses is overly simplistic. While the change from land to sea represents a dramatic and permanent shift for preexisting human populations, the process of change is driven by a complex set of physical and cultural processes with long transitional phases of landscape and socioeconomic change. Here, we use reconstructions of prehistoric sea-level rise, paleogeographies, terrestrial landscape change, and human population dynamics to show how the gradual inundation of an island archipelago resulted in decidedly nonlinear landscape and cultural responses to rising sea levels. Interpretation of past and future responses to sea-level change requires a better understanding of local physical and societal contexts to assess plausible human response patterns in the future.

Mid-Late Holocene Paleoenvironmental and Sea Level Reconstruction on the Al Lith Red Sea Coast, Saudi Arabia

“…A more rigorous assessment of Holocene sea level changes in eastern Saudi Arabia by Parker et al (2020) showed that the transgression rose above mean sea level at about 7000 year BP and the mean highest high tide water level was recorded as up to 3.75 m above present sea level at 5400 year BP. The Late Holocene sea level fall in the Red Sea follows the global sea level pattern (Ramsay and Cooper, 2002;Siddall et al, 2003;Sloss et al, 2018) but differs from that in the Mediteranean Sea where sea level is continuing to rise (Barnett et al, 2020).…”

Artificial shorelines lack natural structural complexity across scales

“…They must balance the usual considerations of cost, engineering and social and environmental impact assessment, while also building-in space in their design envelope for habitat provision [ 71 ]. With this balancing act becoming increasingly complex, incorporation of multiscale structural complexity and environmentally sensitive design may be vital for meeting biodiversity targets in the coastal environment [ 37 , 72 ]. Our results highlight the specific scales at which artificial structures are particularly deficient in structural complexity compared to natural shores, and which could be the focus of future targeted interventions.…”

Population level models for testing hunter-gatherer resilience and settlement response to the combined impact of abrupt climatic events and sea level change: A case study from the Holocene of northern Britain

“…Although the extent of postglacial sea level change has long been recognised, its impact on Mesolithic communities has received surprisingly limited study and is also a subject of contrasting views. Sea level rise can have positive impacts on hunter-gatherers by increasing the extent of resource-rich inter-tidal areas and providing new routes of travel by expanding sea ways (Barnett et al, 2020). Lewis et al (2020) attributed population growth in Scandinavia to the high levels of marine productivity that arose from a combination of sea level rise and increasing temperature.…”

“…For both past and future sea level rise these impacts disturb invertebrate, fish, bird, and sea mammal communities; they destabilise food-webs with consequences for hunter-gatherer resource availability. Benjamin et al (2017) noted that sea level rise in the Mediterranean Basin flooded coastal sites, displaced fishing and shell fishing grounds, creating isolated environments in the form of new islands, bays, and straits, while Barnett et al (2020) described the increased vulnerability of insular and island communities arising from sea level rise. In northern regions, where isostatic rebound was significant, the fall in relative sea level may have had equivalent environmental and economic impacts.…”