As a consequence of climatic change, climate variability is expected to increase and climate extremes to become more frequent. Rising water and food demand are further exacerbating the risks to global water and food security. The variability but also the spatial inter-connectedness in our globalized world make our systems more vulnerable to shocks and disasters. To sustain the global water and food security, more knowledge about risks, especially risks of simultaneous shocks is needed. This thesis maps and quantifies risks to global water and food security from a water-food-climate perspective. It starts on a global scale looking at water security in major river basins and then concentrates on major food producing regions of three important crops. The thesis explores how storage can buffer inter- and intra-regional hydrological variability. A water balance model is developed and used to find hotspots of water shortages and to identify river basins where more investment in infrastructure is needed to improve and sustain water security. Looking at food security, global wheat, maize and soybean breadbaskets are identified and used to estimate risks of simultaneous production shocks. Focusing on wheat, I apply different copula approaches to model joint risks of low yields. It is shown quantitatively that (i) it is important to include spatial dependencies in risks studies and that (ii) inter-regional risk pooling could decrease post-disaster liabilities of governments and international organizations. The last part of the thesis focuses on climate impacts on food production. Relevant climate variables for crop growth in the breadbaskets are identified and joint climate risks are estimated using regular vine copulas. It is shown that so far, only wheat has experienced an increase in simultaneous climate risks. In maize and soybean production regions, positive and negative climate risk changes are offsetting each other on a global scale. Looking at future projections, however, it is shown that under a 1.5 and 2 °C global mean warming, simultaneous climate risks increase for all three crops, especially for maize where the return periods of all five breadbaskets experiencing climate risks decrease from 16 to every second year. The findings of this thesis can inform policy makers, businesses and international organizations about risks to global water and food security resulting from climate variability and extremes. It indicates where policies and infrastructure investments are needed to maintain water security, it can assist in building inter-governmental risk pooling schemes and contribute to current climate policy discussions.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:729305 |
| Date | January 2017 |
| Creators | Gaupp, Franziska |
| Contributors | Hall, Jim ; Dadson, Simon |
| Publisher | University of Oxford |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | https://ora.ox.ac.uk/objects/uuid:a9a1a456-0f3f-4795-8b9d-149cd804aeb0 |
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