The risk to food security posed by global environmental change is one of the most significant threats to health and economic stability for a large fraction of the world’s population. Studies suggest a strong response of crops to climate variability and change, due to impacts of changes in e.g. water availability, and temperature (e.g. Challinor et al., 2014). In addition to climate, surface tropospheric ozone pollution is known to impact crop yield, by limitation of plant growth, acceleration of leaf senescence, and direct injury to leaf tissue (McKee et al., 1997). Several studies provide evidence of ozone-induced reduction in crop yield in sensitive major food crop species in Europe and North America, with an estimated annual cost to arable production of ~7 billion Euro and $2-4 billion respectively. Despite this progress in knowledge, few studies have integrated both climatic and ozone impacts; and studies that assess associated nutritional implications are extremely rare or non-existent.
The aim of the PhD is to quantify the combined impact of climate change and ozone on crops and nutrition using the GLAM-ROC model
- A number of scenarios will be investigated, including current legalization, and a number of mitigation scenarios. The approach will be to investigate potential realistic emission pathways over the next 30-50 years, focusing on the climate and tropospheric ozone responses to these scenarios, and determining their coupled impacts on crop productivity and nutrition. An important component of this work will be the development and evaluation of GLAM-ROC for combined stresses, especially ozone plus drought.
- The study regions will be determined as part of the project, based on an initial analysis of ozone damage hotspots, and investigation of regions where potential interactions between drought stress and ozone stress may become increasingly important. For analysis of such regional focus areas (e.g. India, Southern Europe), high-resolution regional model output is available.
- The project will make use of a robust dataset of observed impacts of ozone and other abiotic stressors (heat and drought) on grain yield, protein and mineral nutrient content available through an ongoing collaboration with the University of Arhus. The dataset will be used to extend the GLAM-ROC model to represent plant responses to environmental stresses, an in particular the metabolism and/or accumulation of particular nutrients. We will combine this knowledge with human dietary intake data to assess the demands for nutrients in selected populations in high-ozone scenarios.
The GLAM-ROC model (Droutsas et al., 2020) is a world-leading approach, developed at Leeds, to the modelling of crop response to ozone and climate. The model expresses crop responses to environment as a set of simultaneous equations, which are then solved using the Newton–Raphson method. This project will use GLAM-ROC to quantify the effect of varying atmospheric ozone concentrations on the yield and nutritional properties of selected crops, beginning with wheat. Existing ozone and climate output from the UK Earth System Model (UKESM) model will be used to drive GLAM-ROC for a range of climate and pollution emissions scenarios. These UKESM simulations are driven by new state-of-the-art emissions datasets for short-lived climate pollutants (SLCPs) (including ozone precursors), developed for recent assessment of SLCP climate and air quality impacts.
You will join the vibrant Climate Impacts research group of 12 Academic Staff and Postgraduate Researchers. There are about 80 PhD students across the Institute for Climate and Atmospheric Science (ICAS) covering climate, air pollution, meteorology and climate impacts, with extensive programmes in observations, modelling and lab studies. Atmospheric science at Leeds is ranked 9th in the Centre for World University Rankings (http://cwur.org/2017) and 13th in the Academic Ranking of World Universities out of 400 (http://www.shanghairanking.com). Wider interdisciplinary experience is guaranteed through our new cross-campus Priestley Centre (http://climate.leeds.ac.uk). Peer exchange and learning occurs through frequent institute and group seminars, discussion meetings and paper review groups.
The project would suit a numerate student with a science background and experience of quantitative analysis who is enthusiastic about problem solving and the use of simulation modelling programmes. The student will be provided with training including the methods and tools needed and will have access to a broad spectrum of training workshops offered in house e.g. image analysis, presentation skills, through to ‘managing your degree’ and ‘preparing for your viva’ (http://www.emeskillstraining.leeds.ac.uk/).
Challinor, A.J., Watson, J., Lobell, D.B., Howden, S.M., Smith, D.R., Chhetri, N. (2014). A meta-analysis of crop yield under climate change and adaptation. Nature Climate Change. 4, pp.287 – 291.
Droutsas, I., Challinor, A.J., Arnold, S.R., Mikkelsen, T.N., Hansen, E.M.O., (2020). A new model of ozone stress in wheat including grain yield loss and plant acclimation to the pollutant. European Journal of Agronomy. 120, article no: 126125.