Continental-Scale Partitioning of Fire Emissions During the 1997 to 2001 El Niño/La Niña Period

Guido R Van Der Werf,Prasad S Kasibhatla,Avelino F Arellano,G James Collatz,Louis Giglio,Seth C Olsen,James T Randerson,Eric S Kasischke

doi:10.1126/science.1090753

Guido R Van Der Werf, Prasad S Kasibhatla + Show 6 more

Open Access

https://doi.org/10.1126/science.1090753

Copy DOI

Abstract

During the 1997 to 1998 El Niño, drought conditions triggered widespread increases in fire activity, releasing CH4 and CO2 to the atmosphere. We evaluated the contribution of fires from different continents to variability in these greenhouse gases from 1997 to 2001, using satellite-based estimates of fire activity, biogeochemical modeling, and an inverse analysis of atmospheric CO anomalies. During the 1997 to 1998 El Niño, the fire emissions anomaly was 2.1 +/- 0.8 petagrams of carbon, or 66 +/- 24% of the CO2 growth rate anomaly. The main contributors were Southeast Asia (60%), Central and South America (30%), and boreal regions of Eurasia and North America (10%).

Highlights

We evaluated the contribution of fires from different continents to variability in these greenhouse gases from 1997 to 2001, using satellite-based estimates of fire activity, biogeochemical modeling, and an inverse analysis of atmospheric CO anomalies
Converting these CO emissions anomalies to total carbon emissions anomalies by using published emissions factors [23], we found that Southeast Asia accounted for ϳ60% of the carbon emissions during the El Nino period (Table 1), with other important and previously underestimated contributions from Central America and northern South America (20%), boreal forests (10%), and southern South America (10%)
A previous study has identified wetlands as the primary source of the anomaly in the northern extratropics [5], our analysis suggests that almost all of the CH4 anomalies observed during 1997 and 1998 in this region can be attributed to fires

Summary

Introduction

We evaluated the contribution of fires from different continents to variability in these greenhouse gases from 1997 to 2001, using satellite-based estimates of fire activity, biogeochemical modeling, and an inverse analysis of atmospheric CO anomalies.

Results

Conclusion