11% higher methane emissions from livestock
New estimates of methane emissions from livestock are 11 per cent higher than figures obtained using established methods for calculations based on the IPCC 2006 emission factors. The reasons for this is that the size and numbers of cattle has changed in many regions, as well as management practices. There has been an 8.4 per cent increase in enteric fermentation methane, and a 36.7 per cent increase in manure management methane.
The study includes updated information for cattle and swine by region, based on reported recent changes in animal body mass, feed quality and quantity, milk productivity, and management of animals and manure. Based on this data, the researchers have been able to calculate new emission factors.
The new factors for enteric fermentation for dairy cattle are higher in all regions except Eastern Europe and most notably in Eastern/Southeastern Asia and Africa. Another significant result is that the factor for dairy cattle manure management has more than doubled in the US and Canada, because of an increase in manure managed in lagoon systems.
Source: Carbon Balance and Management, 29 September 2017, https://cbmjournal.springeropen.com/articles/10.1186/s13021-017-0084-y