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Based on the yearly land cover maps in the study area from 2000 to 2016 referred to in Kiswanto et al. 2018, the change in carbon stock for each period was estimated using the IPCC guideline for national GHG inventories (IPCC, 2006) for agriculture, forestry, and other land use (AFOLU) by calculating carbon stock difference before (B) and after (A), multiplying by the total changed area, and divided by interval year periods (Eq. (1.1)):

(1.1)

where:

ΔC_BA= annual change in carbon stock from the change in the land cover, tC yr^‐1

C_B= carbon stock of the land cover class before (B) the change, tC ha^‐1

C_A= carbon stock of the land cover class after (A) the change, tC ha^‐1

ƩA=total amount of the changed area of the land cover, ha

t₁= year of before the change

t₂= year of after the change

The sign (–/+) of the calculation result represents the C stock difference. The positive (+) stock difference represents the increase in C stocks known as negative emission (sequestration). The negative (–) stock changes represent the decreases in C stocks known as positive emission (emission). The remaining unchanged land cover class during the analysis period or among similar carbon stock would be estimated as no emission. For example, Table 1.1 showed similar carbon stock for paddy/rice field and port and harbor (5 tC yr^–1), transmigration areas and mixed dry agriculture (10 tC yr^–1), and bare ground, mining area, open swamp, open water, fish pond/aquaculture, and cloud/no data (0 tC yr^–1). The CO₂ emission based on the total C stock difference was estimated for each land cover class every year by multiplying the total C stock change by 44/12.