Measurement and analysis of bioenergy greenhouse gases (MAGLUE)
Led by Professor Gail Taylor at the University of Southampton, this project aims to quantify the real GHG balance of different land use transitions to bioenergy crops, for both UK and imported bioenergy feedstocks. More details can be found below:
Against this background of increased demand, there remains significant uncertainty on whether the use of biomass for energy is environmentally sustainable. Any type of managed land use can incur a carbon ‘debt’ – a net loss of carbon or other greenhouse gases to the atmosphere that contributes to global warming. Other greenhouse gases include methane and the oxides of nitrogen. But quantifying the net impact of a bioenergy crop relative to what it might replace (sometimes called the counterfactual), is less than straightforward. This has led to many claims and counter-claims from commercial interests, environmental groups and academics, on the real greenhouse gas impact of land use change to bioenergy systems, where there still remains much disagreement and controversy.
The project described here is aimed at addressing this controversial issue – quantifying the real GHG balance of different land use transitions to bioenergy crops, for both UK and imported bioenergy feedstocks. We will deploy sophisticated state-of-the-art instrumentation that is able to measure GHGs very rapidly, to gain a better insight into the dynamic range of GHG emissions that can occur in such systems, including when fields are ploughed and planted and when fertilisers are added. Following data collection, we will extend our analysis by modelling a wide geographical range across the UK and for biomass feedstock sourced from other areas of the world. The models we use should work if we can utilise available datasets, globally, for weather, soils and yield data of the range of crops of interest.
The GHG data in such systems are usually used to develop emissions factors that are inputted into whole life cycle assessments (LCAs) of carbon (or C equivalent) costs, but these in the past have often been unverified data. We will assess the quality of past data and from our measurement and model campaigns we can test the effectiveness of emissions factors and how they might be improved from our work, including for overseas feedstocks. Finally, in an allied project we have developed a value chain model to optimise the technology options for the UK for bioenergy, depending on how cost, GHG balance and land availability are defined. We will run this model to identify the best bioenergy chains, in terms of GHG balance, for the UK and test scenarios (‘what if’ questions), to determine how much imported feedstock might be sustainable in the future.