Wetter environment and increased grazing reduced the area burned in northern Eurasia from 2002 to 2016

Wei Min Hao,Florent Mouillot,L Scott Baggett,Bryce L Nordgren,Rachel E Corley,Alexander Petkov,Chao Yue,Yves Balkanski,Shawn P Urbanski,Philippe Ciais,Matthew C Reeves

doi:10.5194/bg-18-2559-2021

Abstract

Abstract. Northern Eurasia is currently highly sensitive to climate change. Fires in this region can have significant impacts on regional air quality, radiative forcing and black carbon deposition in the Arctic which can accelerate ice melting. Using a MODIS-derived burned area dataset, we report that the total annual area burned in this region declined by 53 % during the 15-year period from 2002 to 2016. Grassland fires dominated this trend, accounting for 93 % of the decline in the total area burned. Grassland fires in Kazakhstan contributed 47 % of the total area burned and 84 % of the decline. A wetter climate and increased grazing are the principle driving forces for the decline. Our findings (1) highlight the importance of the complex interactions of climate–vegetation–land use in affecting fire activity and (2) reveal how the resulting impacts on fire activity in a relatively small region such as Kazakhstan can dominate the trends in burned areas across a much larger landscape of northern Eurasia.

Highlights

Fire activity worldwide is very sensitive to climate change and human actions, especially over high-latitude ecosystems (Goetz et al, 2007)
We focused on Kazakhstan, as it was the region with the largest decline in burned area in northern Eurasia
Forest is the major ecosystem that covers 27 % of northern Eurasia (Friedl et al, 2010), but it only contributes to 18 % of the total area burned

Summary

Introduction

Fire activity worldwide is very sensitive to climate change and human actions, especially over high-latitude ecosystems (Goetz et al, 2007). Identifying and unraveling confounding drivers of fire is critical for understanding the recent and future impacts of fire activity. In northern Eurasia, fire activity impacts of chief concern include carbon cycling, boreal ecosystem dynamics, fire emissions (Hao et al, 2016a), accelerated ice melting in the Arctic (Hao et al, 2016a; Evangeliou et al, 2016), early thawing of permafrost and the hydrological cycle at high latitudes (IPCC, 2014). An improved understanding of the region’s fire dynamics can be applied to develop climate change mitigation policy and can be incorporated into the fire modules of Earth system models to improve their predictions (Hantson et al, 2016). The global mean surface temperature rose by approximately 0.72 ◦C from the year 1951 to 2012 according to the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC, 2013), but it remained relatively constant (“warming slowdown”) from 1998 to 2013

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