Research into the abolition of milk quotas and agriculture’s contribution to greenhouse gas (GHG) emissions has found that GHG emission intensity per kilogramme (kg) of milk produced decreased by 13% between 2000 and 2017.
This means that dairy farmers are producing each kg of milk with considerably fewer emissions than 20 years ago.
The research – a collaboration between the National University of Ireland Galway (NUI Galway), Teagasc and University of California, Davis – drew on data from the Teagasc National Farm Survey from (2000-2017), as well as data on emissions per farm, calculated as part of the work Teagasc conducts on sustainability.
The aim of the research was to explore how changes in production methods have influenced GHG emission intensity during a time of significant policy change for the dairy sector, specifically the abolition of milk quotas in 2015.
Dr. Doris Laepple, lecturer at NUI Galway explained to Agriland:
“We were interested in conducting this research as Ireland’s dairy sector is growing and is heavily livestock dependent.
“Agriculture accounts for 35% of GHG emissions. Cutting these requires a contribution from agriculture.”
GHG emissions and efficiency
The research also found that dairy farmers have made considerable improvements in terms of environmental efficiency over time.
Dr. Laepple explained:
“Absolute GHG emissions have increased by 86% per farm between 2000-2017, while milk output has increased on average by 123% over the same time.
“This suggests that, without improvement in environmental efficiency of production, farm-level emissions would have increased to a greater extent.”
A ‘strong negative correlation’ between productivity and emission per kg of milk produced was also identified.
“This means increased productivity is associated with lower GHG emission intensity,” she added.
‘Not a panacea’
So, what do these findings mean for the dairy industry?
“On average, productivity increases can contribute to lowering GHG emission intensities,” Dr. Laepple said.
“However, pushing productivity growth as a mitigation option for GHG emissions from the dairy sector is not a panacea.
“For instance, if dairy farms expand output through greater use of chemical fertiliser or imported purchased feeds, this could lead to productivity gains, but at the same time increased emission intensity and, consequently, higher total GHG emissions.”
Productivity gains need to be achieved through increasing output with the same or fewer inputs, such as improved breeding or grassland management, she added.
GHG emission intensity are GHG emissions per litre (L) of milk produced.
Absolute GHG emissions are GHG emissions per farm (these are also calculated by enterprise, i.e. dairy). Lower emission intensity will result in lower total emissions when milk production is constant, this link gets more complicated when milk production increases, as has been the case in Ireland over the last decade.