Wildfire national carbon accounting: how natural and anthropogenic landscape fires emissions are treated in the 2020 Australian government greenhouse gas accounts report to the UNFCCC

Table 1 Thresholds and number of ‘natural disturbances’ caused by unmanaged forest fires in Australian States and Territories between 1990–2020 in the Australian National Greenhouse Gas Inventory [17]

	Geographic UNIT	Units	Statistic based on 2000–2012 baseline)	Threshold value	Number natural disturbance years
Step 1 Gross GHG emissions	National	CO²-e kt	µ + 2 σ	71,950	6
Step 2 Area burned by fire	Australian Capital Territory (ACT)	kha	µ + σ	0.01	3
	New South Wales (NSW)	kha	µ + σ	223.92	3
	Queensland (QLD)	kha	µ + σ	167.94	2
	South Australia (SA)	kha	µ + σ	42.40	3
	Tasmania (TAS)	kha	µ + σ	16.77	4
	Victoria (VIC)	kha	µ + σ	122.01	5
	Western Australia (WA)	kha	µ + σ	348.36	4

Estimation involves a two-step process: estimation of nationally anomalous (> mean (µ) plus two standard deviations (σ)) GHG emissions for a given year relative to 2002–2012 reference period (Step 1). If a given year is considered anomalous in Step 1, then the area burned in each State and Territory is estimated, to determine if this exceeds the threshold by one standard deviation of the non-natural disturbance years (Step 2). This only applies to non-natural disturbance years. Years with natural disturbances for a given state are excluded from the calculation. Emission from ‘natural disturbance years’ are deemed force majeure and not reported as human-induced emissions in the GHG accounts of each State or Territory. Northern Territory is excluded from the NGGI assessment because the ‘national definition of natural disturbances applies to wildfires in temperate forests, and does not apply to fires reported as controlled burning (e.g. in temperate forests or in wet-dry tropical forests and woodlands)’ [17]

ISSN: 1750-0680