Incorrect interpretation of carbon mass balance biases global vegetation fire emission estimates

N C Surawski; A L Sullivan; S H Roxburgh; C P Mick Meyer; P J Polglase

doi:10.1038/ncomms11536

Incorrect interpretation of carbon mass balance biases global vegetation fire emission estimates

Nat Commun. 2016 May 5:7:11536. doi: 10.1038/ncomms11536.

Authors

N C Surawski¹, A L Sullivan², S H Roxburgh², C P Mick Meyer³, P J Polglase²

Affiliations

¹ CSIRO Agriculture, GPO Box 1700, Canberra, Acton 2601, Australian Capital Territory, Australia.
² CSIRO Land and Water, GPO Box 1700, Canberra, Acton 2601, Australian Capital Territory, Australia.
³ CSIRO Oceans and Atmosphere, 107-121 Station Street, Aspendale, Victoria 3195, Australia.

Abstract

Vegetation fires are a complex phenomenon in the Earth system with many global impacts, including influences on global climate. Estimating carbon emissions from vegetation fires relies on a carbon mass balance technique that has evolved with two different interpretations. Databases of global vegetation fire emissions use an approach based on 'consumed biomass', which is an approximation to the biogeochemically correct 'burnt carbon' approach. Here we show that applying the 'consumed biomass' approach to global emissions from vegetation fires leads to annual overestimates of carbon emitted to the atmosphere by 4.0% or 100 Tg compared with the 'burnt carbon' approach. The required correction is significant and represents ∼9% of the net global forest carbon sink estimated annually. Vegetation fire emission studies should use the 'burnt carbon' approach to quantify and understand the role of this burnt carbon, which is not emitted to the atmosphere, as a sink enriched in carbon.