New studies indicate that methane emissions from slurry storage on dairy farms could be up to five times higher than previously reported figures. This research also points out a significant opportunity to convert these emissions into renewable energy.
Recent findings show that methane emissions from slurry storage at dairy farms may be five times more than what official numbers report, emphasizing the potential for transformation into a renewable energy resource.
The research reveals that if this emitted methane were captured and converted into biogas, it could save the dairy industry over £400 million annually in fuel costs, which averages out to approximately £52,500 for a typical dairy farm.
Existing capture technologies, if implemented across the European dairy farms, could decrease emissions by up to an estimated 5.8% of the remaining global temperature increase allowance, assuming the goal is to maintain warming below 1.5 °C.
This study, conducted by the University of East Anglia (UEA) alongside the International Fugitive Emissions Abatement Association (IFEAA), is based on emission measurements from two dairy farms located in Cornwall, England. In conjunction with a growing body of international field studies, it suggests that the ‘Tier 2’ estimation methods used by countries to report emissions to the Intergovernmental Panel on Climate Change (IPCC) may not be precise.
Current National Inventories reporting greenhouse gas (GHG) emissions suggest that enteric emissions, which come from the digestion of animals, are three to nine times larger than emissions from manure management practices, such as slurry storage and application.
However, the new findings, published in Environmental Research: Food Systems and a white paper from the IFEAA Net Zero Methane Hub today, propose that the emissions balance between enteric sources and manure management could be closer to an even split of 50:50. The authors stress the need for more research focus and political attention on manure management emissions.
Professor Neil Ward from the Tyndall Centre for Climate Change Research at UEA remarked, “The conventional international methods appear to underestimate methane emissions from slurry storage.”
“Fortunately, we possess the technology to convert this issue into a business advantage for farmers, enabling them to reduce energy costs and gain energy independence by utilizing methane as a fuel source.”
“If manure management emissions are significantly underestimated, this has implications not only for the accuracy of official statistics but could also skew priorities for mitigation strategies.”
“This study is therefore an urgent call to action for further research into methane emissions from manure management.”
The researchers evaluated emissions from slurry lagoons at the two farms during 2022-2023, using airtight covers to capture the methane.
The analysis revealed that the real methane emissions from slurry lagoons far exceed current official estimates based on IPCC methods. Actual emissions were found to be 145 kg and 198 kg per cow per year for the two respective farms, which is four to five times the official UK estimate of 38 kg per cow included in the National Inventory.
Recommendations for the government include prioritizing research and development, increasing financial grants for slurry covering technologies, and extending funding for related gas processing systems.
Professor Penny Atkins, CEO of IFEAA, stated, “We have the technology for capturing, processing, and using methane that is currently escaping into the atmosphere and adding to greenhouse gas levels. Economically, this path shows promise, especially if supportive investment incentives and regulatory frameworks are established for farms.”
“The overall impact of methane from dairy farm manure management is significant, and this data underscores the urgency of taking measures to reduce these emissions.”
The researchers also recommend streamlining planning and permitting processes and offering tax incentives for investments aimed at methane recovery and utilization, such as those made by milk processors working with supplier farms.
George Eustice, the former Secretary of State for Environment, Food and Rural Affairs and chair of IFEAA, added, “Methane is a powerful but short-duration greenhouse gas, and it is crucial to lower emissions as part of the journey toward Net Zero and restricting global temperature increases to 1.5 degrees.”
“While it is concerning that agricultural emissions are higher than previously estimated, it is reassuring that this methane can be captured easily and used as an alternative to fossil fuels, providing farms with an additional revenue stream.”
