Communicating the uncertainty in estimated greenhouse gas emissions from agriculture

In an effort to mitigate anthropogenic effects on the global climate system, industrialised countries are required to quantify and report, for various economic sectors, the annual emissions of greenhouse gases from their several sources and the absorption of the same in different sinks. These estimates are uncertain, and this uncertainty must be communicated effectively, if government bodies, research scientists or members of the public are to draw sound conclusions. Our interest is in communicating the uncertainty in estimates of greenhouse gas emissions from agriculture to those who might directly use the results from the inventory. We tested six methods of communication. These were: a verbal scale using the IPCC calibrated phrases such as ‘likely’ and ‘very unlikely’; probabilities that emissions are within a defined range of values; confidence intervals for the expected value; histograms; box plots; and shaded arrays that depict the probability density of the uncertain quantity. In a formal trial we used these methods to communicate uncertainty about four specific inferences about greenhouse gas emissions in the UK. Sixty four individuals who use results from the greenhouse gas inventory professionally participated in the trial, and we tested how effectively the uncertainty about these inferences was communicated by means of a questionnaire. Our results showed differences in the efficacy of the methods of communication, and interactions with the nature of the target audience. We found that, although the verbal scale was thought to be a good method of communication it did not convey enough information and was open to misinterpretation. Shaded arrays were similarly criticised for being open to misinterpretation, but proved to give the best impression of uncertainty when participants were asked to interpret results from the greenhouse gas inventory. Box plots were most favoured by our participants largely because they were particularly favoured by those who worked in research or had a stronger mathematical background. We propose a combination of methods should be used to convey uncertainty in emissions and that this combination should be tailored to the professional grou

Analysis of uncertainties in the estimates of nitrous oxide and methane emissions in the UK’s greenhouse gas inventory for agriculture

The UK’s greenhouse gas inventory for agriculture uses a model based on the IPCC Tier 1 and Tier 2 26 methods to estimate the emissions of methane and nitrous oxide from agriculture. The inventory 27 calculations are disaggregated at country level (England, Wales, Scotland and Northern Ireland). 28 Before now, no detailed assessment of the uncertainties in the estimates of emissions had been 29 done. We used Monte Carlo simulation to do such an analysis. We collated information on the 30 uncertainties of each of the model inputs. The uncertainties propagate through the model and result 31 in uncertainties in the estimated emissions. Using a sensitivity analysis, we found that in England and 32 Scotland the uncertainty in the emission factor for emissions from N inputs (EF1) affected 33 uncertainty the most, but that in Wales and Northern Ireland, the emission factor for N leaching and 34 runoff (EF5) had greater influence. We showed that if the uncertainty in any one of these emission 35 factors is reduced by 50%, the uncertainty in emissions of nitrous oxide reduces by 10%. The 36 uncertainty in the estimate for the emissions of methane emission factors for enteric fermentation 37 in cows and sheep most affected the uncertainty in methane emissions. When inventories are 38 disaggregated (as that for the UK is) correlation between separate instances of each emission factor 39 will affect the uncertainty in emissions. As more countries move towards inventory models with 40 disaggregation, it is important that the IPCC give firm guidance on this topic

The landscape model: a model for exploring trade-offs between agricultural production and the environment

We describe a model framework that simulates spatial and temporal interactions in agricultural landscapes and that can be used to explore trade-offs between production and environment so helping to determine solutions to the problems of sustainable food production. Here we focus on models of agricultural production, water movement and nutrient flow in a landscape. We validate these models against data from two long-term experiments, (the first a continuous wheat experiment and the other a permanent grass-land experiment) and an experiment where water and nutrient flow are measured from isolated catchments. The model simulated wheat yield (RMSE 20.3–28.6%), grain N (RMSE 21.3–42.5%) and P (RMSE 20.2–29% excluding the nil N plots), and total soil organic carbon particularly well (RMSE 3.1 − 13.8 %), the simulations of water flow were also reasonable (RMSE 180.36 and 226.02%). We illustrate the use of our model framework to explore trade-offs between production and nutrient losses

Interpretation and Relevance:​ Metadata challenges for Broadbalk, the world’s longest running agricultural experiment

Presentation on the challenges for presenting metadata for Broadbalk, the world's longest continuously running agricultural experiment. Presented at Springer Nature & Wellcome Trust Better Science through Better Data 2017 (#scidata17), London, 25^th October 201

The potential distribution of bioenergy crops in the UK under present and future climate

We have predicted the potential distribution of 26 bioenergy crops in the UK, based on the simple model described by Tuck et al. [1]. The model has been applied at a 5 km resolution using the UKCIP02 model for scenarios at Low, Medium-Low, Medium-High and High emissions. In the analysis of the results the limitations for crop growth are assigned to elevation, temperature, high and low rainfall. Most of the crops currently grown are predicted to remain prevalent in the UK. A number of crops are suitable for introduction to the UK under a changing climate, whereas others retreat to northern parts of the UK. The greatest changes are expected in England. The simplicity of the model means that it has a relatively high uncertainty, with minor modifications to the model leading to quite different results. Nevertheless, it is well suited for identifying areas and crops that are most likely to be affected by the greatest changes. It has been noted that Miscanthus and Short Rotation Coppice (SRC) willow and poplar, which are currently regarded as highly suitable for UK conditions, may be less suited to southern areas in the future, where, for example, kenaf could have a greater potential. Further investigations are required to reduce uncertainty associated with the projections based on this simple model and to make conclusions more firmly

Report to NERC : InformaTec Soils : report for the InformaTec-Soils meeting at Defra, Nobel House, March 14th 2011

InformaTec is a 2-year, NERC-funded project that seeks to identify how to manage the increasing wealth of environmental data and information so that it can be transmitted, distributed, stored, archived, analysed and visualised, and in so doing, aims to recognise and develop opportunities for knowledge and technology transfer, both nationally and internationally. As such, InformaTec addresses a major objective of the NERC science strategy, namely, the “exploitation of technological advances to develop improved methods of monitoring environmental change.” InformaTec-Soils is one component of InformaTec; other aspects of the project focus on environmental monitoring, data standards, interoperability, and distributed computing. The specific aim of InformaTec-Soils is to draw together key players having interest in the collection and synthesis of large-scale soil data sets with a view to identifying what needs to be done to improve understanding of soil and environmental change. As part of the InformaTec-Soils initiative, a meeting of 24 experts from across the UK was convened at Defra, in London, on 14 March 2011. Through presentations, roundtable discussions and breakout groups, the meeting explored, current informatics, methodological and cultural challenges, and constraints, to the synthesis of UK and European soils data for understanding soil and environmental change. This report presents a vision for an ecosystems approach to soils and summarizes the conclusions and recommendations of the meeting held in London. As well as identifying opportunities for the soils community generally, the report will be presented to NERC to inform decisions on future funding. The authors of the report extend their gratitude to all who contributed to the meeting and the production of this report. The report identifies the following important research topics for soils: Key areas for research: 1) Framework development. 2) Quantifying the soil resource, stocks, fluxes, transformations and identifying indicators. 3) Valuing the soil resource for its ecosystem services and natural capital. 4) Developing management strategies and decision support tools. Within these 4 key areas for research we identify the following 5 major challenges that the NERC technologies theme should address: Major research challenges: 1. Ecosystem approach to national soil monitoring; how we measure and model at a range of scales. 2. Exploit new technologies for airborne, ground based sensor networks, and molecular biology techniques to link from structure through to function and on to service. 3. Develop data accessibility (via cloud), and integration by exploiting new data IT tools (eg Open MI) to support projects building exemplar or baseline data/models eg EVOp project (Community). 4. Decision support tools, simple, practical tools for people trying to utilize and visualise data for a range of common purposes (e.g. planning). 5. Pathways to ‘valuation’. How do you link users perceptions of value to the parameters created by the data and models? (e.g developing techniques from social–science research in terms of perceptions and value judgements). Some of the challenges and opportunities to arise from the meeting with regard to ‘Data Handling’ and ‘Measurement Methods and Technologies’ are identified in two appendices to the report

Nutrient Management in Support of Environmental and Agricultural Sustainability

Given that we must farm land in order to eat, the total environmental burden imposed by farming a crop, such as winter wheat in the UK, appears to be close to the minimum given current production techniques. The value of the services other than food production, such as flood water buffering, pollination, carbon storage and so on, that land can provide is relatively large compared with the value in reducing environmental burdens from pesticide use, nutrient pollution and greenhouse gas emissions that might arise by farming less intensively. More land will need to be brought into cultivation in order to provide the same amount of food if the intensity of farming is reduced and the resultant loss of ecosystem services (ES) outweighs the reduction in other burdens. Nevertheless, losses of nutrients, especially nitrogen (N), from agriculture are a serious concern and the current cost of the environmental footprint of agriculture is significant compared with the value of the food it produces. This article examines nutrient burdens and analyses the means by which the total environmental burden might be reduced relative to productivity. These include increasing the efficiency of farming, removing constraints to yield, and establishing multiple uses for land at the same time as farming. It concludes that agronomic measures which improve nutrient capture and which obtain more yield per unit area are valuable means to avoid degradation of environmental quality because both nutrient pollution and land consumption can be avoided