PRESS RELEASE: New SGI review clarifies the greenhouse gas emissions from the natural gas supply chain

CaptureThe Sustainable Gas Institute, at Imperial College London, launches today their first major piece of research – a White Paper, a comprehensive review of the available literature on methane and carbon dioxide emissions from the natural gas supply chain.

The authors examined over 250 papers to gain a comprehensive view of the current global profile of emissions. The report considered both conventional and unconventional methods of extracting natural gas (e.g. shale gas).

Natural gas has been regarded as environmentally cleaner than coal with respect to global warming. When combusted, it produces half as much CO2 than coal. However, releases of greenhouse gases can occur before natural gas is used for energy; for example, leakages can occur when it is being extracted, transported and processed.

The review explores some major questions such as how much methane and carbon dioxide is released in the production process, in order to see where they can be minimised.

Lead author Dr Paul Balcombe, from the Imperial College London, explained, “We found an extremely wide range of emission estimates across the supply chain, and our review highlights specific stages that have the largest emissions”.

“However, there is potential to significantly reduce any higher emissions with the use of modern equipment and effective operation and maintenance procedures. The aim of this paper is that it will serve as a crucial reference document on emissions for academia, the gas industry and policy makers.”

The report details what factors (e.g. equipment, procedures) affect emission ranges in order to understand the climate mitigation potential at each stage.


The key findings:

  • The range of greenhouse gas emissions across the supply chain is vast across a range of processes, stages, regions, and equipment.
  • The distribution of emissions estimates within studies is skewed by a small number of high-emitters or super emitters.
  • High emissions sources can be minimised with the use of modern equipment and effective operation and maintenance strategies.
  • There is a lack of data, particularly outside of the US.
  • One of the key challenges for research is to improve and standardise measurement techniques, as estimation methods varied significantly in the literature.


Professor Nigel Brandon, Director of the Sustainable Gas Institute at Imperial, added:

“With COP-21 on the horizon, this report comes at a critical time, with industry, policy makers, regulators and governments all making decisions on how they will respond to climate change.  The report shows that fugitive emissions of methane and carbon dioxide in the production and distribution of natural gas need to be reduced if we are to deliver a more sustainable natural gas supply chain, and identifies areas where efforts should be targeted to achieve this.”

Professor Jim Watson, Director, UK Energy Research Centre, commented on the review’s significance:

“This review provides important evidence to inform the debate on the role of gas in a low carbon energy system. Crucially, it highlights some of significant uncertainties in current estimates of emissions from different sources of natural gas – and also what could be done to tackle some of those emissions.’

For more information on this topic or to speak with an expert please contact:

Zara Qadir (Communications Manager) at or +44 (0)207 594 8875


Notes for editors:

About the White Paper Series

  • White Papers are systematic reviews of published literature within a given scope which provide an authoritative summary of the current state of play, clarifying contentious issues and identifying areas for further research.
  • The Sustainable Gas Institute (SGI) White Papers are targeted at a relatively non-technical audience to provide easy access for policy makers and industry.
  • The White Paper was developed with the help of an expert advisory group, who have offered valuable comments and guidance on the scoping and final report.

About the Sustainable Gas Institute (

  • In May 2014, the Sustainable Gas Institute (SGI), was launched in partnership with Imperial College London and BG Group, as the first collaborative academic centre for research, technology and education in gas sustainability.
  • The Institute draws on world-class expertise to answer key research questions on energy efficiency, gas innovation, and carbon capture, storage and use, in order to explore the role of natural gas in emerging low carbon energy systems.

Please download the PRESS RELEASE PDF Version.