Estimation of Methane Enteric Fermentation from Ruminants in Indonesia Using ALU Software at Tier 1 and Tier 2 Levels

ABSTRACT The estimation of methane enteric fermentationemission from ruminants in Indonesia using the Tier 1 approach seems to overestimatefrom the actual emission value. Onthe other hand, using Tier 2 is very complicated because of very diverse circumstance of managements and environmental systems in Indonesian livestock. The purpose of this study was to compare the estimation of ruminant enteric emissions in Indonesia using the Tier 1 and Tier 2 approaches. Those estimations were calculated using the “Agriculture and Land Use-National Greenhouse Gas Inventory” (ALU) Software. The livestock (buffalo, dairy cattle, beef cattle, sheep and goats) population data were from the Indonesian Livestock and Animal Health Statistics by 2016. At Tier 1 approach, we used the default emission factors of IPCC (2006), while at Tier 2,we used emission factors for livestock subcategories. The values were obtainedfrom enhanced inventory data and other data such as age, animal productivity, diet quality and management circumstances; afterward by ALU software, the data were entered step by step to estimate methane emission from each type of livestock. The estimated enteric methane emissions using Tier 1 was1,030,851 Gg CH4yr-1, consisted of 74,532; 36,307; 752,193; 78,583; and 89,236 Gg CH4 yr-1 from buffalo, dairy cows, beef cattle, sheep and goats, respectively. Using Tier 2 approach it was845,951 consisted of 60,578;26,262; 596,931; 72,944and 89,236 Gg CH4yr-1,from buffalo, dairy cattle, beef cattle, sheep and goats, respectively. This concluded that the Tier 2 estimation of enteric methane emissions of major livestock in Indonesia was 15% lower than that of Tier 1. The Tier 2 estimation was likely to be closer with the actual condition