Methane emissions from slurry stores on dairy farms may be up to five times greater than official statistics suggest, a new study by the University of East Anglia has found.
According to the study, Estimating methane emissions from manure: a suitable case for treatment?, which was published in the Environmental Research journal, the findings illustrate the potential for turning said emissions into a renewable energy source.
Underestimating emissions
“The standard international methodology looks to be underestimating methane emissions from slurry storage,” commented Prof Neil Ward, of the Tyndall Centre for Climate Change Research at UEA.
“Fortunately, we have the technology to turn this problem into a business opportunity for farmers who can reduce energy bills and become energy independent if they capture and make use of methane as a fuel.”
The researchers estimate that methane conversion could save more than £400 million a year in fuel costs, providing an average-sized dairy farm with savings of around £52,500 annually.
Capture technology already exists, they note, and if said technology was rolled out across the EU dairy herd, the resulting biofuel could reduce emissions equivalent to an estimated 5.8% of the remaining global temperature rise budget (if temperatures were to be kept to 1.5C of warming).
“If emissions from manure management are being significantly under-estimated, this not only means that official estimates are inaccurate, but also that priorities around mitigation options might be being distorted,” Ward added. “This research therefore represents an urgent call for action and further work to better understand methane emissions from manure management.”
Greenhouse gas contribution
The study, conducted in collaboration with the International Fugitive Emissions Abatement Association (IFEAA), found that current national inventories might overlook methane emissions from slurry storage, which could be contributing much more to greenhouse gases than previously thought.
While enteric emissions from cows’ digestive systems have traditionally been seen as the primary source, this new data suggests that emissions from manure management may be nearly equal to this – potentially accounting for 50% of dairy-related methane emissions.
“The technology exists for capturing, processing and utilising the methane that is currently lost to the atmosphere and contributing to GHG accumulation, and looks economically promising particularly if an incentives framework for capital investment on farms, coupled with regulatory support, can be implemented,” added Prof Penny Atkins, IFEAA CEO.
“The cumulative contribution of methane from dairy farm manure management is significant and this data shows we must act now to curb emissions.”
More information on the report can be found here.
