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Implications of farm-scale methane mitigation measures for long-term national methane emissions - CC0270

Methane (CH4) is the second most important greenhouse gas after CO2, contributing 20% to global warming. Agriculture (particularly dairy farming) contributes 43% to the UK’s emissions of CH4 and under the Kyoto Protocol there is a target to reduce these by 12.5% of the 1990 levels. A number of CH4 mitigation measures have been suggested and identified but there is a need to know whether these would be effective over broad spatial scales and under future scenarios. Additionally it is necessary to ascertain whether widespread implementation of these mitigations would have other consequences e. g. for levels of production and emissions of other pollutants. In this project we shall identify a range of potentially effective measures for reducing CH4 emissions from livestock (dairy) farming in England and Wales. The effectiveness of these measures will be quantified at the farm, regional and national scales through concerted scenario exploration with a new modelling framework comprising 3 linked, existing models. The 3 models are the Reading rumen model, the IGER NGAUGE field/farm model and the CEH AENEID countrywide spatial model. The project involves some modifications to the existing models to enable suitable interfacing and time-step compatibilities. The Reading model will be driven by inputs from NGAUGE which will together simulate emissions of CH4 from animals (according to diet, level of production and herd management), from manure managements and unmanaged areas of the farm and also emissions of NH3, N2O and NO3- (according to site soil and weather factors and farm managements). Leaching of phosphorus will be dealt with using a separate export coefficient approach based upon fertiliser input, site factors and feed and manure quality. These emissions will be passed on to the CEH model which will assess the impacts of measures against baseline strategies when scaling up to regions and nationally and over projected futures of 1, 3 and 10 years. The main project deliverable is a detailed assessment and quantification of the effectiveness of CH4 mitigation strategies that could be applied to dairy farms and the impacts of these on other forms of atmospheric and water pollution at broad spatial scales within selected regions of England and Wales and nationally.
The overall objective of the project is to investigate the implications of various methane mitigation measures, often investigated at the individual animal- to farm- scale, on long-term national emissions The objectives of the work are; 1. To carry out a review of the feasibility, cost and potential benefits and risks of options for methane abatement 2. Feed these data into mechanistic and non-linear models of productivity, methane and nitrogen emissions at an animal and herd level3. Integrate the outputs of these models into a whole farm model taking into account other sources of methane (manure management) and describing the influence of variables such as climate, soil type, grassland area and farming practice on N2O and NH3 emissions and NO3- and phosphorus leaching 4. Relate whole farm model outputs to a spatial consideration of agricultural practice within the UK considering the consequences of displaced production and the potential for increased national production 5. Scenario test over a 1, 3 and 10 year time framework to take into account impacts of mitigation strategies over the longer term, e.g. to take into account predicted trends in UK dairy farm management and rates of replacements at the herd level.
Project Documents
• Final Report : Implications of farm-scale methane mitigation measures for long-term national methane emissions   (1358k)
Time-Scale and Cost
From: 2004

To: 2005

Cost: £59,826
Contractor / Funded Organisations
Institute of Grassland and Environment Research (IGER)
Air quality monitoring              
Environmental monitoring              
Environmental Protection              
Fields of Study
Agriculture and Climate Change