Climate, water and society in arid regions: from ancient civilizations to the Anthropocene

The largest region of arid climate stretches from North Africa, across the Middle East and into Central Asia. In these regions, water availability is an important restriction and yet this is where the first cities, first kingdoms and first empires rose and fell. Many of these societal changes have been shown to correlate with fluctuations in rainfall and climate, but often these changes are relatively small (for example ~10% change in precipitation; Hill, 2019; Cookson et al., 2019) and the mechanisms through which these changes affect society are poorly understood. There are important hydrological changes happening in these areas today, through both contemporary climate change and water management, such as the drying of lakes (Figure 1), and the loss of agricultural land (Kelley et al., 2015). Many of these dry regions are expected to experience significantly greater rainfall changes in the coming centuries due to anthropological climate change (IPCC, 2021; Lyon et al., 2021).

 

Utilising novel transient climate model simulations, climate and hydrological changes over the last 6000 years will be assessed. Combining these new simulations with new and emerging datasets of long term settlement patterns, land use, demographic change and environmental proxies, will provide powerful new tools to understand the changing nature of human-environment interactions in these areas. These datasets will feed water balance calculations and modelling of key basins, potentially including the Nile River Basin, the Dead Sea, the Tigris-Euphrates Basin and the Aral Sea. These same models can then be used to assess the impact of modern climate changes, extraction policies and agricultural practices, as well as assess the impact of future climate changes on hydrology.

 

Figure 1: NASA satellite images of the Aral Sea in 1989 (left) and 2014 (right).

 

Project Objectives

Although there is plenty of scope for candidates to tailor the research programme to their own interests, the following represents a reasonable expectation of what the project could aim to address:

  • Assess existing climate model simulations in relation to hydrological and societal changes over the last 6000 years in the arid regions of North Africa, the Middle East and central Asia.
  • Develop models of the hydrological systems in these regions and how the climatological and societal impacts change over time.
  • Simulate and understand present and future changes in these hydrological systems and how they may affect the populations that live here.

 

Training and Research Environment

The student will be trained in the analysis of large climate datasets and will have the opportunity to gain skills in the setting up, running and development of a variety of models. Being based in the Palaeo@Leeds research group, within the Earth Surface Science Institute (ESSI) and the Institute for Climate and Atmospheric Science (ICAS) gives the student access to a wealth of palaeoclimate, hydrological and climate change expertise. The project will also require collaboration with archaeologists (including Dan Lawrence, Durham University), historians (including Nir Arelli, University of Leeds) and a broad range of palaeoclimate researchers. As part of the Panorama NERC DTP, there will be many opportunities to develop new skills. The student will be expected to attend and present at national and international scientific meetings.

 

Student Profile

No applicant will have all the required skills and knowledge prior to starting this PhD and the strong interdisciplinary nature of the research means that it is suitable for a broad range of academic backgrounds. These include, but are not limited to physics, maths, environmental science, oceanography, archaeology, computer science etc. Numeracy, computing and programming skills would be an advantage, but are not essential.

 

References

Cookson, E. et al., 2019. Impacts of long term climate change during the collapse of the Akkadian Empire, Journal of Archaeological Science, 106:1-9.

Hill, D.J., 2019. Climate Change and the Rise of the Central Asian Silk Roads. In: Socio-Environmental Dynamics along the Historical Silk Road. Springer, Cham.

IPCC, 2021. Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press.

Kelley, C.P. et al., 2015. Climate change in the Fertile Crescent and implications of the recent Syrian drought. PNAS, 112:3231-3246.

Lyon, C. et al., 2021. Climate change research and action must look beyond 2100. Global Change Biology, 00, 1-13.