Prof N Unger
Prof P M Cox
No more applications being accepted
Funded PhD Project (Students Worldwide)
Professor Nadine Unger, University of Exeter
Professor Peter Cox, University of Exeter
Dr Fiona O’Connor, UK Met Office Hadley Centre
Dr Gerd Folberth, UK Met Office Hadley Centre
College of Engineering, Mathematics, and Physical Sciences, Streatham Campus, Exeter
The University of Exeter’s College of Engineering, Mathematics and Physical Sciences is inviting applications for a fully-funded PhD studentship to commence in September 2019 or as soon as possible thereafter. For eligible students the studentship will cover tuition fees (UK/EU/International) plus an annual tax-free stipend of at least £14,777 for 3.5 years full-time, or pro rata for part-time study. The student will be based in Mathematics in the College of Engineering, Mathematics and Physical Sciences at the Streatham Campus in Exeter.
The studentship will be awarded on the basis of merit for 3.5 years of full-time study to commence in September 2019.
Methane mitigation is a critical component of achieving humanity’s goal to limit global warming to less than 1.5°C or 2°C. Through atmospheric oxidation, methane is linked to all short-lived climate pollutants, including ozone and aerosols. Methane mitigation increases the allowable carbon budget and reduces global surface ozone with co-benefits to human and ecosystem health. Agriculture (30-40%), landfill (10-20%) and fossil fuel energy-use (30-40%) are the largest global human sources of methane in today’s world. In addition, methane has substantial natural sources from wetland ecosystems that are sensitive to climate change. Methane behaves as both a human-induced climate forcing and a climate feedback in the Earth system.
Methane’s atmospheric growth rate and variability depend on changes in human and natural emissions, and changes in the atmospheric oxidation capacity. Past and present changes in methane growth rate remain enigmatic because of uncertainties in the global methane budget. For example, atmospheric methane has experienced puzzling dynamics over the past 15 years. After a period of relative stagnation in the early 2000s, atmospheric methane concentrations have increased rapidly since 2007 at more than ten times that rate. What is controlling these puzzling methane dynamics? Changes in human emissions, natural emissions, or oxidation capacity, or a combination of all?
Evolution of global atmospheric methane 1980-2012.
For the first time, this exciting project takes a new approach to identifying constraints on methane in the Earth system in our rapidly forced climate. Emergent constraints are relationships between observable variations in the Earth System and future changes, which are evident across an ensemble of models. This project applies multiple measurement and model data to reveal new insights into the atmospheric methane dynamics with a particular focus on the past 3 decades. Improved understanding of atmospheric methane variability is a requirement for accurate quantification of the role of methane in global climate mitigation. This PhD position is suitable for candidates with a strong quantitative background who are interested in international policy-relevant climate research and data science.
The main goals include: (1) Quantify relationships between satellite and surface methane observations and drivers of variability including climatic variables, oxidation capacity and emissions; (2) Apply an Earth system box model to examine factors controlling the past and present variability in atmospheric methane, and quantitatively explain key features in past 20 years including the slow-down in the early 2000s and current rapid growth; (3) Perform and analyse Earth system methane climate mitigation experiment simulations with UK-ESM1 in collaboration with UK Met Office Hadley Centre.
Cox, P.M., C. Huntingford, M.S. Williamson, Emergent constraint on equilibrium climate sensitivity from global temperature variability, Nature, 553, 319-322, doi:10.1038/nature25450, 2018.
Chadburn, S.E., E.J. Burke, P.M. Cox, P. Friedlingstein, G. Hugelius, S. Westermann, An observation-based constraint on permafrost loss as a function of global warming, Nature Climate Change, 7, 340-344, doi:10.1038/nclimate3262, 2017.
Harper K.L, Y. Zheng, N. Unger, Advances in representing interactive methane in ModelE2-YIBs (version 1.1), Geoscientific Model Development, 11, 4417-4434, doi:10.5194/gmd-11-4417-2018, 2018.
Saunois, M., R.B. Jackson, P. Bousquet, B. Poulter, J.G. Canadell, The growing role of methane in anthropogenic climate change, Environmental Research Letters, 11, doi.org/10.1088/1748-9326/11/12/120207, 2016.
Saunois, M., et al., The global methane budget 2000-2012, Earth Syst. Sci. Data, 8, 697-751, https://doi.org/10.5194/essd-8-697-2016, 2016.