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A more direct assessment of emissions from offshore oil and gas industries

Prof Alastair Lewis (YDC), Dr Ruth Purvis (YDC)

Project partner(s): BEIS (CASE)

Contact email:


The reporting of offshore atmospheric emissions of air pollutants forms a key part of the UK’s commitments to international agreements that limit both greenhouse gases and trans-boundary air pollution.  The UK regulatory bodies and operators are known worldwide for their “Gold standard regulation” in the field of offshore oil & gas.  The initial emission estimates from oil and gas facilities are assessed before permits are issued and then reported as a regulatory requirement when in operation using EEMS (Environmental Emissions Monitoring System). The Department for Business, Energy and Industrial Strategy (BEIS), and other government departments, regard EEMS as a key source of evidence for environmental policy and data reported in EEMS is used to confirm regulatory compliance, to meet government’s national and international reporting requirements and to inform policy development and implementation. Emissions are based on ‘bottom-up’ estimates and supported by periodic stack monitoring as directed BEIS. Crucially however there is no independent methodology for confirming whether the industry-reported emissions of air pollutants from any given installation are correct.  This makes the modelling  the dispersion of emissions difficult and does not confirm whether the emission estimates detailed in the permit applications or reported emissions into EEMS are reliable or need to be reviewed.

Techniques developed by NCAS for monitoring gas plumes during the Elgin gas release, and subsequently more widely across the North Sea, have demonstrated that airborne monitoring, coupled with innovative atmospheric modelling, can comprehensively survey large areas and many individual installations for their emissions within a few hours (800 nautical miles covered in 4 hours at one altitude). This ‘top-down’ approach to emissions assessment estimates the total released loads calculated from the elevation of various gases in the downwind plume. This approach has the potential to provide the regulator, BEIS, with an innovative new tool to validate emissions in practice, and has the potential to provide a monitoring method that is lower cost to the industry than regular stack monitoring surveys and more relevant to impact assessment.

The PhD will use a combination of existing observations of offshore measurements from the North Sea, alongside new data collection, to determine a links between atmospheric emissions and installation operations. The PhD will evaluate emissions of species including nitrogen oxides (NOx),  methane (CH4) and carbon dioxide (CO2) and non-methane hydrocarbons and use modelling techniques to calculate emissions estimates.


The student will take the research lead on the development of new knowledge and better estimates of atmospheric emissions arising from offshore oil and gas installations.

  1. Collect a comprehensive, quality controlled dataset of atmospheric CO2, CH4, NO, NO2, NOx, ethane, SO2 and H2S in the West of Shetland area. New installations are due to be commissioned in the near future and the study will provide a baseline for current regional pollutant levels against which the emissions from the new installations can be assessed, and provide data relating to the atmospheric levels of pollutants relating to specific existing and new installations.
  2. Collect a comprehensive, quality controlled dataset of atmospheric plumes of CO2, CH4, NO, NO2, NOx, ethane, SO2 and H2S downwind of selected installations in the North Sea.
  3. Compare the estimated emissions of atmospheric releases for specific installations with calculated emissions loads derived from records of operational activity during the study periods using current EEMS methodologies, to determine whether the methodologies should be reviewed.
  4. Investigate the use of pollutant ratios to discriminate between atmospheric pollutant loads relating to combustion activities (energy generation and flaring) and pollutant loads relating to hydrocarbon releases (venting and fugitives), to determine whether reporting methodologies for specific inputs should be reviewed.
  5. Translate the new observational and modeling science into policy advice on emissions from the oil and gas sector to the UK government and to other international bodies.

Potential for high impact outcome       

This project is a unique opportunity to lead cutting edge research into the emissions from the offshore oil and gas installations and to work on high impact environmental science, alongside a key UK commercial sector. The project is a CASE studentship and will work in partnership with BEIS to ensure the science generated is translated to users directly.  

Some of our recent examples of high impact science related to oil and gas emissions and pollution emissions from other sectors can be found at:

Lee, J et al. (2017), submitted Atmospheric Measurement Technique (

D. Helmig, S Rossabi, J Hueber, P Tans, S Montzka, K Masarie, K Thoning, C Plass-Duelme, A.C Lewis, L.J Carpenter, S Punjabi, S Reimann, M. Vollmer, R Steinbrecher, J Hannigan, L Emmons, E Mahieu, B Franco, D Smale & A Pozzer. A Reversal of global atmospheric ethane and propane trends largely due to US oil and gas production, Nature Geoscience. 9, 490-495, 2016.

A.C Lewis and Edwards P.M. Validate personal air pollution sensors. Nature, 535, 29-31, 2016.

A.R Vaughan, J.D Lee, P.K Misztal, S Metzger, M.D Shaw, A.C Lewis, R.M Purvis, D.C Carslaw, A.H Goldstein, C.N Hewitt, B Davison, S.D Beevers, & T.G Karl. Spatially resolved flux measurements of NOx from London suggest significantly higher emissions than predicted by inventories. Faraday Discussions. 189, 455- 473, 2016.

SMEDLEY, P L, WARD, R S, ALLEN, G, BAPTIE, B, DARAKTCHIEVA, Z, JONES, D G, JORDAN, C J, PURVIS, R M AND CIGNA, F. 2015. Site selection strategy for environmental monitoring in connection with shale-gas exploration: Vale of Pickering, Yorkshire and Fylde, Lancashire. British Geological Survey Open Report, OR/15/067. 22 pp.

Ward, R.S.; Smedley, P.S.; Allen, G.; Baptie, B.J.; Daraktchieva, Z.; Horleston, A.; Jones, D.G.; Jordan, C.J.; Lewis, A.; Lowry, D.; Purvis, R.M.; Rivett, M.O.. 2017 Environmental Baseline Monitoring Project. Phase II, final report. British Geological Survey, 163pp. (OR/17/049)


The student will work under the supervision of Dr Ruth Purvis, Prof Alastair Lewis at the Wolfson Atmospheric Chemistry Laboratories, part of the University of York’s Department of Chemistry, and NERCs National Centre for Atmospheric Science. The studentship is offered as part of the SPHERES Doctoral Training Programme that will provide training in addition to that offered by the department. Through both the departmental and SPHERES training, there are a wide range of training activities, including courses aimed at specific science objectives, at improving your transferable skills and putting your work into a wider scientific context.

Dr Purvis will provide comprehensive training in the technical aspects of the instrumentation used and the data analysis, whilst Prof Lewis will support areas of research including sampling and analytical strategies, and policy engagement.

Wolfson Atmospheric Chemistry Laboratories

The student will work in the Wolfson Atmospheric Chemistry Laboratories (WACL), part of the department of Chemistry, University of York. These were established in 2013 and comprise a state of the art 800 m2 dedicated research building, the first of its kind in the UK. Supported by a large award from the Wolfson Foundation and a private donor, the Laboratories enable experimental and theoretical studies relating to the science of local and global air pollution, stratospheric ozone depletion and climate change. The Laboratories offer access to state of the art facilities for atmospheric science, including analysis labs, workshops, prototyping facilities, high performance computation and data analysis. WACL provides an environment with exceptional scientific and technical support for PhDs including full-time experimental officers, instrument design, data and fieldwork specialists. The Laboratories are operated as collaborative venture between the University of York and the National Centre for Atmospheric Science (NCAS), co-locating around 55 researchers from seven academic groups and from NCAS. The Laboratories are a vibrant home to independent research fellows, postdoctoral researchers, PhD students and final year undergraduate research projects.

Related undergraduate subjects:

  • Applied mathematics
  • Atmospheric science
  • Chemistry
  • Computer science
  • Computing
  • Earth science
  • Earth system science
  • Engineering
  • Environmental policy
  • Environmental science
  • Mathematics
  • Mechanical engineering
  • Meteorology
  • Physical science
  • Physics