Mobile integrated greenhouse gas assessment system (MIGGAS): targetting Net Zero.

This proposal is for a mobile integrated greenhouse gas assessment system (MIGGAS), to locate and isotopically identify greenhouse gas sources, and calculate emission fluxes. MIGGAS will be capable of deployment either on a moving vehicle, to map urban and rural emissions, or as a static installation in field campaigns. Should the request be granted, the university promises funding to develop a technically advanced high precision mid-infrared drone-mounted sensor, to operate directly with MIGGAS.

The UK is the global leader in committing for net zero carbon emissions by 2050. This demands far-reaching change to locate and reduce emissions of all major greenhouse gases and to remove them from the atmosphere. While focus is usually on carbon dioxide, methane emissions from industry, domestic gas use, sewers and landfills will also need to be drastically cut. Moreover, both CO2 and CH4 budgets will need measurement as the landscape changes, be it through restoration of peatland, increase in forest cover or change in agricultural land-use to growing biofuels. Whole-life greenhouse gas budgets of these changes are poorly known and urgently need to be quantified.

Emission fluxes can be quantified by either eddy covariance or with mobile instrumentation to map emissions and model plumes. MIGGAS will do both. The instrumentation will be field deployable for short campaigns and the high frequency (10 Hz) measurements of methane and carbon dioxide coupled to a 3D sonic anemometer allows eddy covariance to be used to calculate fluxes. It is also deployable on mobile platforms (car or boat) for emission mapping. A portable methane and CO2 analyser can pinpoint exact locations of emissions and can be connected to a chamber for very local real time emission flux calculations.

The RHUL team are very experienced in high precision measurements of methane isotopic ratios in air samples collected in the field and then analysed in the lab. Adding ability to carry out isotopic measurements in the field allows real time source apportionment, powerfully advancing specific source identification, for example where landfills, gas leaks and animal barns are closely juxtaposed.

Linked to the proposal is the college's exciting promise of providing funds to develop a very advanced drone-mounted mobile sensing system using mid-infrared optics that will deliver much higher-precision than currently available sensors. This will create a world-best integrated system for locating, identifying and quantifying greenhouse gas emissions.

Methane is particularly poorly known, with large uncertainties in fluxes from both natural and anthropogenic sources. Globally, methane's rise since 2007 threatens the Paris Agreement (e.g. Nisbet et al., 2019, GBC). Emissions urgently need to be cut. Different sources are often co-located (e.g. shale gas extraction next to cattle feedlots) but identifiable via differences in isotopic composition and ethane:methane ratio, allowing accurate source apportionment. The instruments will be primarily used in the UK as the nation seeks "Net Zero", but MIGGAS will also be deployable overseas for field campaigns, with close colleagues in Europe, Australia, Hong Kong and Kuwait.

Topics to be addressed include: 1) better understanding of changing emissions in the UK - how much are landfill methane emissions declining and how large are methane emissions from rapidly growing numbers of biogas plants? 2) What are the methane and CO2 balances of new sustainable forests, or 3) fields of bioenergy crop, and 4) how does this depend on soil and plant type? 5) How are natural methane emissions from water bodies and peats changing in a warming climate? Ultimately we address the big question - how can the UK, and the world, achieve net zero carbon emissions and keep warming below 1.5 degrees C?

By developing state-of-the-art instrumentation for coupled source location, flux quantification and isotopic identification, the new MIGGAS system will have far-reaching scientific impact and, further, will make a powerful contribution to achieving a major target in public policy. The primary impact will be to improve the UK's chance of success of achieving Net Zero carbon emissions by 2050, to meet the Paris Agreement's goals.

Accurate measurement and targetting of methane emissions is essential if the UK is to achieve 'Net Zero' carbon emissions by 2050. This is what the MIGGAS system will achieve, immediately as a mobile vehicle-mounted system, and then in partnership with the innovative new high precision drone technology whose development it will help make possible. Royal Holloway was one of the first labs worldwide to adopt high precision cavity-based mole fraction measurement for methane: our previous lab choices have been very widely followed. Similarly, our CF-IRMS methodology for isotopic analysis of methane has helped lead European work in the field for 15 years, as our WP2 leadership on the H20:20 MEMO2 project testifies.

The results from our studies of emissions from different energy sectors (e.g. offshore and onshore gas, biogas, bioenergy) will directly inform government as plans are made for future energy provision. Similarly studies of emissions from different types of land use will inform policy makers how progress can be made towards reducing carbon emissions.

The scientific impact will be strong. We don't know why methane began rising in 2007, nor why that rise accelerated in 2014, and a key factor behind that lack of knowledge is the absence of good isotopic measurement and emission rates of sources. Our recent 2019 paper in Global Biogeochemical Cycles has a current Altmetrics impact rating >750, highest of all papers in the journal and in the top 7k of the 13 million papers surveyed by Altmetrics for impact. Interest is very strong: in this decade our team has produced papers in 2016 with >100, 2014 with >200, and 2011 with >300 Scopus citations. Results will be made available to the scientific community and will be well publicised at international conferences and in high impact publications.

There will be wide media impact. This research has an important impact on public perception of climate change and thence on public policy. There is currently deep interest in how to reduce impending climate warming and we have had intense media interest following recent publications in this field. As examples, the 2016 and 2019 synthesis papers from NERC's MOYA consortium were very widely reported in the international print and broadcast media. Nature and Science have both reported on our work, and long-read articles on our science have been published, inter alia, in The Economist, Los Angeles Times, with lengthy news reports in the FT, Observer, Daily Mail, NZZ-Zurich, New Scientist etc. etc. For example, in a long-read piece, the South China Morning Post called our prototype mobile system the "Gasbusters".

Impact to industry - gas extraction, distribution, landfills and biogas - is very important. In the UK, for BEIS we carry out environmental baseline monitoring associated with shale gas extraction. Although we do not accept industry funding, we are in close touch with corporate colleagues in the gas industry, landfill management and with industry regulatory bodies. The new facility will provide advances in mapping source distributions and quantifying fluxes; powerful tools in mitigation efforts, improving the ability of major energy companies to find and cut gas leaks and other industrial emissions.

The instrumentation will be used as a teaching tool in our Environmental M.Sc course and the portable methane and carbon dioxide analyser will also be ideal for use in outreach events where we can show the public how greenhouse gas emissions can be measured and how they are distributed.